Spanwise transition section for blended wing-body aircraft

NASA Technical Reports Server (NTRS)

Hawley, Arthur V. (Inventor)

1999-01-01

A blended wing-body aircraft includes a central body, a wing, and a transition section which interconnects the body and the wing on each side of the aircraft. The two transition sections are identical, and each has a variable chord length and thickness which varies in proportion to the chord length. This enables the transition section to connect the thin wing to the thicker body. Each transition section has a negative sweep angle.

ED01-0230-1

NASA Image and Video Library

2001-08-13

NASA's Helios Prototype aircraft taking off from the Pacific Missile Range Facility, Kauai, Hawaii, for the record flight. As a follow-on to the Centurion (and earlier Pathfinder and Pathfinder-Plus) aircraft, the solar-powered Helios Prototype is the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions in the stratosphere. Developed by AeroVironment, Inc., of Monrovia, California, under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project, the unique craft is intended to demonstrate two key missions: the ability to reach and sustain horizontal flight at 100,000 feet altitude on a single-day flight in 2001, and to maintain flight above 50,000 feet altitude for at least four days in 2003, with the aid of a regenerative fuel cell-based energy storage system now in development. Both of these missions will be powered by electricity derived from non-polluting solar energy. The Helios Prototype is an enlarged version of the Centurion flying wing, which flew a series of test flights at NASA's Dryden Flight Research Center in late 1998. The craft has a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of its solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. The remotely piloted, electrically powered Helios Prototype went aloft on its maiden low-altitude checkout flight Sept. 8, 1999, over Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center in the Southern California desert. The initial flight series was flown on battery power as a risk-reduction measure. In all, six flights were flown in the Helios Protoype's initial development series. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingsp

Moveable Leading Edge Device for a Wing

NASA Technical Reports Server (NTRS)

Pitt, Dale M. (Inventor); Eckstein, Nicholas Stephen (Inventor)

2013-01-01

A method and apparatus for managing a flight control surface system. A leading edge section on a wing of an aircraft is extended into a deployed position. A deformable section connects the leading edge section to a trailing section. The deformable section changes from a deformed shape to an original shape when the leading edge section is moved into the deployed position. The leading edge section on the wing is moved from the deployed position to an undeployed position. The deformable section changes to the deformed shape inside of the wing.

Experimental and calculated characteristics of three wings of NACA 64-210 and 65-210 airfoil sections with and without 2 degree washout

NASA Technical Reports Server (NTRS)

Sivells, James C

1947-01-01

Report presents the results of an investigation conducted to determine some of the effects of airfoil section and washout on the experimental and calculated characteristics of 10-percent-thick wings. Three wings of aspect ratio 9 and ratio of root chord to tip chord 2.5 were tested. One wing had NACA 64-210 sections and 2 degree washout, the second had NACA 65-210 sections and 2 degree washout, and the third had NACA 65-210 sections and 0 degree washout. It was found that the experimental characteristics of the wings could be satisfactorily predicted from calculations based upon two-dimensional data when the airfoil contours of the wings conformed to the true airfoil sections with the same high degree of accuracy as the two-dimensional models.

Centurion in Flight with Internal Wing Structure Visible

NASA Technical Reports Server (NTRS)

1998-01-01

The lightweight wing structure and covering of the Centurion remotely piloted flying wing can be clearly seen in this photo of the plane during one of its initial low-altitude, battery-powered test flights in late 1998 at NASA's Dryden Flight Research Center, Edwards, California. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Silhouetted under a bright blue sky, a quarter-scale model of the Centurion solar-powered flying wing shows off its long, narrow wing as it flies over the broad expanse of El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Internal-external flow integration for a thin ejector-flapped wing section

NASA Technical Reports Server (NTRS)

Woolard, H. W.

1979-01-01

Thin airfoil theories of an ejector flapped wing section are reviewed. The global matching of the external airfoil flow with the ejector internal flow and the overall ejector flapped wing section aerodynamic performance are examined. Mathematical models of the external and internal flows are presented. The delineation of the suction flow coefficient characteristics are discussed. The idealized lift performance of an ejector flapped wing relative to a jet augmented flapped wing are compared.

Geometric Analysis of Wing Sections

DOT National Transportation Integrated Search

1995-04-01

This paper describes a new geometric analysis procedure for wing sections. This procedure is based on the normal mode analysis for continuous functions. A set of special shape functions is introduced to represent the geometry of the wing section. The...

A swept wing panel in a low speed flexible walled test section

NASA Technical Reports Server (NTRS)

Goodyer, M. J.

1987-01-01

The testing of two-dimensional airfoil sections in adaptive wall tunnels is relatively widespread and has become routine at all speeds up to transonic. In contrast, the experience with the three-dimensional testing of swept panels in adaptive wall test sections is very limited, except for some activity in the 1940's at NPL, London. The current interest in testing swept wing panels led to the work covered by this report, which describes the design of an adaptive-wall swept-wing test section for a low speed wind tunnel and gives test results for a wing panel swept at 40 deg. The test section has rigid flat sidewalls supporting the panel, and features flexible top and bottom wall with ribs swept at the same angle as the wing. When streamlined, the walls form waves swept at the same angle as the wing. The C sub L (-) curve for the swept wing, determined from its pressure distributions taken with the walls streamlined, compare well with reference data which was taken on the same model, unswept, in a test section deep enough to avoid wall interference.

View of center section of south elevation of Building No. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View of center section of south elevation of Building No. 23. South Twenty-sixth Street in foreground. Looking northwest - Easter Hill Village, Building No. 23, North side of South Twenty-sixth Street, east of Corto Square, Richmond, Contra Costa County, CA

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Illuminated by early-morning sunlight, a quarter-scale model of the Solar-powered, remotely piloted Centurion ultra-high-altitude flying wing demonstrates its abilities during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Illuminated by early-morning sunlight, a quarter-scale model of the solar-powered, remotely piloted Centurion ultra-high-altitude flying wing soars over California's Mojave Desert on a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

With the snow-covered San Gabriel Mountains as a backdrop and a motorcycle-mounted chase crew alongside, a quarter-scale model of the Centurion solar-powered flying wing soars over El Mirage Dry Lake on an early test flight in March 1997. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Framed by wispy contrails left by passing jets high above, a quarter-scale model of the Centurion solar-electric flying wing shows off its graceful lines during a March 1997 test flight at El Mirage Dry Lake in California's Mojave Desert. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Trailed by a van carrying the remote pilot and observers, a radio-controlled quarter-scale model of the Centurion solar-electric flying wing makes a low pass over El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing on Lakebed

NASA Technical Reports Server (NTRS)

1997-01-01

A quarter-scale model of the Centurion solar-powered flying wing rests on the clay of El Mirage Dry Lake in Southern California's high desert after completion of of a March 1997 flight test. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing in Flight during Firs

NASA Technical Reports Server (NTRS)

1997-01-01

Silhouetted under a bright blue sky, a quarter-scale model of the Centurion solar-powered flying wing shows off its internal rib structure as it floats over the El Mirage Dry Lake in Southern California during a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing on Lakebed

NASA Technical Reports Server (NTRS)

1997-01-01

A quarter-scale model of the Centurion solar-powered flying wing rests on the clay of El Mirage Dry Lake in Southern California's high desert after completion of a March 1997 test flight. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Problem of the slotted wing : a communication from the Aerodynamic Institute of the Aachen Technical High School

NASA Technical Reports Server (NTRS)

Klemperer, W

1922-01-01

It is to be expected that the advantageous properties, hitherto discovered in many slotted wing sections, depend very largely on the contour of the slot and the structural details of the wing. It is therefore of interest, aside from measurements on wings of constant cross-section along the span, to measure also wing models in which the structural details have already been given practical consideration.

Determination of the Mass Moments and Radii of Inertia of the Sections of a Tapered Wing and the Center-of-Gravity Line along the Wing Span

NASA Technical Reports Server (NTRS)

Savelyev, V. V.

1943-01-01

For computing the critical flutter velocity of a wing among the data required are the position of the line of centers of gravity of the wing sections along the span and the mass moments and radii of inertia of any section of the wing about the axis passing through the center of gravity of the section. A sufficiently detailed computation of these magnitudes even if the weights of all the wing elements are known, requires a great deal of time expenditure. Thus a rapid competent worker would require from 70 to 100 hours for the preceding computations for one wing only, while hundreds of hours would be required if all the weights were included. With the aid of the formulas derived in the present paper, the preceding work can be performed with a degree of accuracy sufficient for practical purposes in from one to two hours, the only required data being the geometric dimensions of the outer wing (tapered part), the position of its longerons, the total weight of the outer wing, and the approximate weight of the longerons, The entire material presented in this paper is applicable mainly to wings of longeron construction of the CAHI type and investigations are therefore being conducted by CAHI for the derivation of formulas for the determination of the preceding data for wings of other types.

33 CFR 334.595 - Atlantic Ocean off Cape Canaveral; 45th Space Wing, Cape Canaveral Air Force Station, FL...

Code of Federal Regulations, 2014 CFR

2014-07-01

...; 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.595 Section 334.595.... The regulations in this section shall be enforced by the Commander, 45th Space Wing, Patrick Air Force... AND RESTRICTED AREA REGULATIONS § 334.595 Atlantic Ocean off Cape Canaveral; 45th Space Wing, Cape...

33 CFR 334.595 - Atlantic Ocean off Cape Canaveral; 45th Space Wing, Cape Canaveral Air Force Station, FL...

Code of Federal Regulations, 2013 CFR

2013-07-01

...; 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.595 Section 334.595.... The regulations in this section shall be enforced by the Commander, 45th Space Wing, Patrick Air Force... AND RESTRICTED AREA REGULATIONS § 334.595 Atlantic Ocean off Cape Canaveral; 45th Space Wing, Cape...

33 CFR 334.595 - Atlantic Ocean off Cape Canaveral; 45th Space Wing, Cape Canaveral Air Force Station, FL...

Code of Federal Regulations, 2012 CFR

2012-07-01

...; 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.595 Section 334.595.... The regulations in this section shall be enforced by the Commander, 45th Space Wing, Patrick Air Force... AND RESTRICTED AREA REGULATIONS § 334.595 Atlantic Ocean off Cape Canaveral; 45th Space Wing, Cape...

33 CFR 334.595 - Atlantic Ocean off Cape Canaveral; 45th Space Wing, Cape Canaveral Air Force Station, FL...

Code of Federal Regulations, 2010 CFR

2010-07-01

...; 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.595 Section 334.595.... The regulations in this section shall be enforced by the Commander, 45th Space Wing, Patrick Air Force... AND RESTRICTED AREA REGULATIONS § 334.595 Atlantic Ocean off Cape Canaveral; 45th Space Wing, Cape...

33 CFR 334.595 - Atlantic Ocean off Cape Canaveral; 45th Space Wing, Cape Canaveral Air Force Station, FL...

Code of Federal Regulations, 2011 CFR

2011-07-01

...; 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.595 Section 334.595.... The regulations in this section shall be enforced by the Commander, 45th Space Wing, Patrick Air Force... AND RESTRICTED AREA REGULATIONS § 334.595 Atlantic Ocean off Cape Canaveral; 45th Space Wing, Cape...

Encouraging Sixth-Grade Students' Problem-Solving Performance by Teaching through Problem Solving

ERIC Educational Resources Information Center

Bostic, Jonathan D.; Pape, Stephen J.; Jacobbe, Tim

2016-01-01

This teaching experiment provided students with continuous engagement in a problem-solving based instructional approach during one mathematics unit. Three sections of sixth-grade mathematics were sampled from a school in Florida, U.S.A. and one section was randomly assigned to experience teaching through problem solving. Students' problem-solving…

Experimental Aerodynamic Characteristics of a Joined-wing Research Aircraft Configuration

NASA Technical Reports Server (NTRS)

Smith, Stephen C.; Stonum, Ronald K.

1989-01-01

A wind-tunnel test was conducted at Ames Research Center to measure the aerodynamic characteristics of a joined-wing research aircraft (JWRA). This aircraft was designed to utilize the fuselage and engines of the existing NASA AD-1 aircraft. The JWRA was designed to have removable outer wing panels to represent three different configurations with the interwing joint at different fractions of the wing span. A one-sixth-scale wind-tunnel model of all three configurations of the JWRA was tested in the Ames 12-Foot Pressure Wind Tunnel to measure aerodynamic performance, stability, and control characteristics. The results of these tests are presented. Longitudinal and lateral-directional characteristics were measured over an angle of attack range of -7 to 14 deg and over an angle of sideslip range of -5 to +2.5 deg at a Mach number of 0.35 and a Reynolds number of 2.2x10(6)/ft. Various combinations of deflected control surfaces were tested to measure the effectiveness and impact on stability of several control surface arrangements. In addition, the effects on stall and post-stall aerodynamic characteristics from small leading-edge devices called vortilons were measured. The results of these tests indicate that the JWRA had very good aerodynamic performance and acceptable stability and control throughout its flight envelope. The vortilons produced a profound improvement in the stall and post-stall characteristics with no measurable effects on cruise performance.

ExFiT Flight Design and Structural Modeling for FalconLAUNCH VIII Sounding Rocket

DTIC Science & Technology

2010-03-01

frequencies of the test specimen. Next, the accelerometers were placed along the trailing edge of both the main wing and winglet sections. In the first...once again used however, the accelerometer originally in the winglet section was moved to the cut out portion of the main wing section. In this test...the part was struck on the joining section of the specimen connecting both main wing and winglet sections. Finally, the ping hammer was loaded with a

A Method for Determining Cloud-Droplet Impingement on Swept Wings

NASA Technical Reports Server (NTRS)

Dorsch, Robert G.; Brun, Rinaldo J.

1953-01-01

The general effect of wing sweep on cloud-droplet trajectories about swept wings of high aspect ratio moving at subsonic speeds is discussed. A method of computing droplet trajectories about yawed cylinders and swept wings is presented, and illustrative droplet trajectories are computed. A method of extending two-dimensional calculations of droplet impingement on nonswept wings to swept wings is presented. It is shown that the extent of impingement of cloud droplets on an airfoil surface, the total rate of collection of water, and the local rate of impingement per unit area of airfoil surface can be found for a swept wing from two-dimensional data for a nonswept wing. The impingement on a swept wing is obtained from impingement data for a nonswept airfoil section which is the same as the section in the normal plane of the swept wing by calculating all dimensionless parameters with respect to flow conditions in the normal plane of the swept wing.

Aircraft Wing for Over-The-Wing Mounting of Engine Nacelle

NASA Technical Reports Server (NTRS)

Hahn, Andrew S. (Inventor); Kinney, David J. (Inventor)

2011-01-01

An aircraft wing has an inboard section and an outboard section. The inboard section is attached (i) on one side thereof to the aircraft's fuselage, and (ii) on an opposing side thereof to an inboard side of a turbofan engine nacelle in an over-the-wing mounting position. The outboard section's leading edge has a sweep of at least 20 degrees. The inboard section's leading edge has a sweep between -15 and +15 degrees, and extends from the fuselage to an attachment position on the nacelle that is forward of an index position defined as an imaginary intersection between the sweep of the outboard section's leading edge and the inboard side of the nacelle. In an alternate embodiment, the turbofan engine nacelle is replaced with an open rotor engine nacelle.

General Potential Theory of Arbitrary Wing Sections

NASA Technical Reports Server (NTRS)

Theodorsen, T.; Garrick, I. E.

1979-01-01

The problem of determining the two dimensional potential flow around wing sections of any shape is examined. The problem is condensed into the compact form of an integral equation capable of yielding numerical solutions by a direct process. An attempt is made to analyze and coordinate the results of earlier studies relating to properties of wing sections. The existing approximate theory of thin wing sections and the Joukowski theory with its numerous generalizations are reduced to special cases of the general theory of arbitrary sections, permitting a clearer perspective of the entire field. The method which permits the determination of the velocity at any point of an arbitrary section and the associated lift and moments is described. The method is also discussed in terms for developing new shapes of preassigned aerodynamical properties.

F-8 supercritical wing flight pressure, Boundary layer, and wake measurements and comparisons with wind tunnel data

NASA Technical Reports Server (NTRS)

Montoya, L. C.; Banner, R. D.

1977-01-01

Data for speeds from Mach 0.50 to Mach 0.99 are presented for configurations with and without fuselage area-rule additions, with and without leading-edge vortex generators, and with and without boundary-layer trips on the wing. The wing pressure coefficients are tabulated. Comparisons between the airplane and model data show that higher second velocity peaks occurred on the airplane wing than on the model wing. The differences were attributed to wind tunnel wall interference effects that caused too much rear camber to be designed into the wing. Optimum flow conditions on the outboard wing section occurred at Mach 0.98 at an angle of attack near 4 deg. The measured differences in section drag with and without boundary-layer trips on the wing suggested that a region of laminar flow existed on the outboard wing without trips.

High performance forward swept wing aircraft

NASA Technical Reports Server (NTRS)

Koenig, David G. (Inventor); Aoyagi, Kiyoshi (Inventor); Dudley, Michael R. (Inventor); Schmidt, Susan B. (Inventor)

1988-01-01

A high performance aircraft capable of subsonic, transonic and supersonic speeds employs a forward swept wing planform and at least one first and second solution ejector located on the inboard section of the wing. A high degree of flow control on the inboard sections of the wing is achieved along with improved maneuverability and control of pitch, roll and yaw. Lift loss is delayed to higher angles of attack than in conventional aircraft. In one embodiment the ejectors may be advantageously positioned spanwise on the wing while the ductwork is kept to a minimum.

Wind-Tunnel Investigation of a Rectangular NACA 2212 Airfoil with Semispan Ailerons and with Nonperforated, Balanced Double Split Flaps for Use as Aerodynamic Brakes

NASA Technical Reports Server (NTRS)

Ivey, Margaret F

1945-01-01

Flat-plate flaps with no wing cutouts and flaps having Clark Y sections with corresponding cutouts made in wing were tested for various flap deflections, chord-wise locations, and gaps between flaps and airfoil contour. The drag was slightly lower for wing with airfoil section flaps. Satisfactory aileron effectiveness was obtained with flap gap of 20% wing chord and flap-nose location of 80 percent wing chord behind leading edge. Airflow was smooth and buffeting negligible.

An Experimental Study of Airfoil Icing Characteristics

NASA Technical Reports Server (NTRS)

Shaw, R. J.; Sotos, R. G.; Solano, F. R.

1982-01-01

A full scale general aviation wing with a NACA 63 sub 2 A415 airfoil section was tested to determine icing characteristics for representative rime and glaze icing conditions. Measurements were made of ice accretion shapes and resultant wing section drag coefficient levels. It was found that the NACA 63 sub 2 A415 wing section was less sensitive to rime and glaze icing encounters for climb conditions.

Shape control of an adaptive wing for transonic drag reduction

NASA Astrophysics Data System (ADS)

Austin, Fred; Van Nostrand, William C.

1995-05-01

Theory and experiments to control the static shape of flexible structures by employing internal translational actuators are summarized and plants to extend the work to adaptive wings are presented. Significant reductions in the shock-induced drag are achievable during transonic- cruise by small adaptive modifications to the wing cross-sectional profile. Actuators are employed as truss elements of active ribs to deform the wing cross section. An adaptive-rib model was constructed, and experiments validated the shape-control theory. Plans for future development under an ARPA/AFWAL contract include payoff assessments of the method on an actual aircraft, the development of inchworm TERFENOL-D actuators, and the development of a method to optimize the wing cross-sectional shapes by direct-drag measurements.

A Comparison of the Experimental and Theoretical Loading over Triangular Wings in Sideslip at Supersonic Speeds

NASA Technical Reports Server (NTRS)

Boyd, John W

1951-01-01

The results of an experimental investigation of the load distribution over two triangular wings in sideslip at Mach numbers from 1.20 to 1.79 are presented and compared with theory. The two wings tested have identical plan form, 45 degrees sweepback of the leading edge, and an aspect ratio of 4.0. One model was composed of round-nose airfoil sections and the other of sharp-nose, biconvex sections. For both wings the maximum thickness of streamwise sections was 6 percent and was located at the 30-percent chord.

Investigation in the Langley 19-foot Pressure Tunnel of Two Wings of NACA 65-210 and 64-210 Airfoil Sections with Various Type Flaps

NASA Technical Reports Server (NTRS)

Sivells, James C; Spooner, Stanley H

1949-01-01

Report presents the results of an investigation conducted in the Langley 19-foot pressure tunnel to determine the maximum lift and stalling characteristics of two thin wings equipped with several types of flaps. Split, single slotted, and double slotted flaps were tested on one wing which had NACA 65-210 airfoil sections and split and double slotted flaps were tested on the other, which had NACA 64-210 airfoil sections. Both wings were zero sweep, an aspect ratio of 9, and a taper ratio of 0.4.

Correction of downwash in wind tunnels of circular and elliptic sections

NASA Technical Reports Server (NTRS)

Lotz, Irmgard

1936-01-01

The downwash velocity distribution behind the wing was determined for the free jet and for the closed tunnel of both circular and elliptic cross sections. The wing was placed at the center of the tunnel. The theory makes it possible to determine the downwash at any point in the jet. The computations were performed for points in the plane determined by the jet axis and the center-of-pressure line of the wing. The downwash proved to be proportional to the wing lift and inversely proportional to the cross-sectional area of the tunnel.

77 FR 45651 - Notice of Filing of Plats

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-01

... during normal business hours. The FIRS is available 24 hours a day, 7 days a week, to leave a message or... INFORMATION: The supplemental plat of the SE1/4SE1/4 of Section 29, in Township 1 North, Range 71 West, Sixth.../4 of Section 25, in Township 1 North, Range 72 West, Sixth Principal Meridian, Colorado, was...

78 FR 79599 - Airworthiness Directives; Various Aircraft Equipped With Wing Lift Struts

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-31

... Airworthiness Directives; Various Aircraft Equipped With Wing Lift Struts AGENCY: Federal Aviation... wing lift struts. The list of affected airplanes in the Applicability section is incorrect. Several... wing lift struts for corrosion; repetitively inspecting the wing lift strut forks for cracks; replacing...

The Challenge to Sixth Form Funding: An Introduction to Government Proposals To Change the Way Sixth Forms Are Funded.

ERIC Educational Resources Information Center

Fletcher, Mick; Boney, Charles

This document, which is intended for senior staff at the United Kingdom's further education (FE) colleges, examines the content and possible impact of recent government proposals to change how school sixth forms are funded. The following are among the topics discussed in sections 1-8: (1) reasons underlying the talk about change; (2) existing…

Centurion on Lakebed during Functional Checkout

NASA Technical Reports Server (NTRS)

1998-01-01

A close-up view of the 14 wide-bladed propellers and electric motors on the Centurion solar-powered, remotely piloted flying wing. This photo was taken during a functional checkout of the aircraft prior to its first test flights at NASA's Dryden Flight Research Center, Edwards, California, in late 1998. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Centurion Quarter-scale Prototype Pre-flight Taxi Test

NASA Technical Reports Server (NTRS)

1997-01-01

As crewmen jog and cycle alongside, a battery-powered, quarter-scale prototype of the remotely-piloted Centurion flying wing rolls across the El Mirage Dry Lake during pre-flight taxi tests. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Centurion Quarter-scale Prototype Pre-flight Checkout

NASA Technical Reports Server (NTRS)

1997-01-01

Technicians perform pre-test checks of a battery-powered quarter-scale prototype of the remotely-piloted Centurion flying wing during taxi tests In March 1997 at California's El Mirage Dry Lake. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Quarter-scale Model of Solar-powered Centurion Ultra-high-altitude Flying Wing Landing during First

NASA Technical Reports Server (NTRS)

1997-01-01

A quarter-scale model of the future Centurion solar-powered high-altitude research aircraft settles in for landing after a March 1997 test flight at El Mirage Dry Lake, California. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Centurion in Flight over Lakebed

NASA Technical Reports Server (NTRS)

1998-01-01

The Centurion remotely piloted flying wing during an early morning test flight over the Rogers Dry Lake adjacent to at NASA's Dryden Flight Research Center, Edwards, California. The flight was one of an initial series of low-altitude, battery-powered test flights conducted in late 1998. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

Elements of the Wing Section Theory and of the Wing Theory

NASA Technical Reports Server (NTRS)

Munk, Max M

1925-01-01

This report contains those results of the theory of wings and of wing sections which are of immediate practical value. They are proved and demonstrated by the use of the simple conceptions of "kinetic energy" and "momentum" only, familiar to every engineer; and not by introducing "isogonal transformations" and "vortices," which latter mathematical methods are not essential to the theory and better are used only in papers intended for mathematicians and special experts.

The effect of morphologically representative corrugation on hovering insect flight

NASA Astrophysics Data System (ADS)

Feaster, Jeffrey; Battaglia, Francine; Bayandor, Javid

2017-11-01

The present work explores the influence of morphologically representative wing corrugation in three-dimensional symmetric hovering. The kinematics are applied to a processed μCT scan of a Bombus pensylvanicus and compared with a wing utilizing the same planform but a flat, rectangular cross-section. The Bombus pensylvanicus wing used in the present study was captured in Virginia, killed with Ethyl acetate dying with wings extended with the fore and hind wings connected by the wing humuli. The aerodynamics resulting from geometric differences between the true wing and flat plate are quantified using CL and CD, and qualified using slices of vorticity and pressure. Three-dimensional flow structures are visualized using vorticity magnitude and streamlines. The present analysis is to begin to determine and understand the effects of insect wing venation on aerodynamic performance and further, to better understand the effects of assuming a simplified cross-sectional geometry.

Development of direct-inverse 3-D methods for applied transonic aerodynamic wing design and analysis

NASA Technical Reports Server (NTRS)

Carlson, Leland A.

1989-01-01

Progress in the direct-inverse wing design method in curvilinear coordinates has been made. This includes the remedying of a spanwise oscillation problem and the assessment of grid skewness, viscous interaction, and the initial airfoil section on the final design. It was found that, in response to the spanwise oscillation problem that designing at every other spanwise station produced the best results for the cases presented, a smoothly varying grid is especially needed for the accurate design at the wing tip, the boundary layer displacement thicknesses must be included in a successful wing design, the design of high and medium aspect ratio wings is possible with this code, and the final airfoil section designed is fairly independent of the initial section.

Airfoil modification effects on subsonic and transonic pressure distributions and performance for the EA-6B airplane

NASA Technical Reports Server (NTRS)

Allison, Dennis O.; Sewall, William G.

1995-01-01

Longitudinal characteristics and wing-section pressure distributions are compared for the EA-6B airplane with and without airfoil modifications. The airfoil modifications were designed to increase low-speed maximum lift for maneuvering, while having a minimal effect on transonic performance. Section contour changes were confined to the leading-edge slat and trailing-edge flap regions of the wing. Experimental data are analyzed from tests in the Langley 16-Foot Transonic Tunnel on the baseline and two modified wing-fuselage configurations with the slats and flaps in their retracted positions. Wing modification effects on subsonic and transonic performance are seen in wing-section pressure distributions of the various configurations at similar lift coefficients. The modified-wing configurations produced maximum lift coefficients which exceeded those of the baseline configuration at low-speed Mach numbers (0.300 and 0.400). This benefit was related to the behavior of the wing upper surface leading-edge suction peak and the behavior of the trailing-edge pressure. At transonic Mach numbers (0.725 to 0.900), the wing modifications produced a somewhat stronger nose-down pitching moment, a slightly higher drag at low-lift levels, and a lower drag at higher lift levels.

Determination of mean camber surfaces for wings having uniform chordwise loading and arbitrary spanwise loading in subsonic flow

NASA Technical Reports Server (NTRS)

Katzoff, S; Faison, M Frances; Dubose, Hugh C

1954-01-01

The field of a uniformly loaded wing in subsonic flow is discussed in terms of the acceleration potential. It is shown that, for the design of such wings, the slope of the mean camber surface at any point can be determined by a line integration around the wing boundary. By an additional line integration around the wing boundary, this method is extended to include the case where the local section lift coefficient varies with spanwise location (the chordwise loading at every section still remaining uniform). For the uniformly loaded wing of polygonal plan form, the integrations necessary to determine the local slope of the surface and the further integration of the slopes to determine the ordinate can be done analytically. An outline of these integrations and the resulting formulas are included. Calculated results are given for a sweptback wing with uniform chordwise loading and a highly tapered spanwise loading, a uniformly loaded delta wing, a uniformly loaded sweptback wing, and the same sweptback wing with uniform chordwise loading but elliptical span load distribution.

Construction, wind tunnel testing and data analysis for a 1/5 scale ultra-light wing model

NASA Technical Reports Server (NTRS)

James, Michael D.; Smith, Howard W.

1993-01-01

This report documents the construction, wind tunnel testing, and data analysis of a 1/5 scale ultra-light wing section. Wind tunnel testing provided accurate and meaningful lift, drag, and pitching moment data. This data was processed and graphically presented as follows: C(sub L) vs. gamma; C(sub D) vs. gamma; C(sub M) vs. gamma; and C(sub L) vs. C(sub D). The wing fabric flexure was found to be significant and its possible effects on aerodynamic data was discussed. The fabric flexure is directly related to wing angle of attack and airspeed. Different wing section shapes created by fabric flexure are presented with explanations of the types of pressures that act upon the wing surface. This report provides conclusive aerodynamic data for ultra-light wings.

Summary Report on the High-Speed Characteristics of Six Model Wings Having NACA 65sub1-Series Sections

NASA Technical Reports Server (NTRS)

Hamilton, William T; Nelson, Warren H

1947-01-01

A summary of the results of wind-tunnel tests to determine the high-speed aerodynamic characteristics of six model wings having NACA 65sub1-series sections is presented in this report. The 8-percent-thick wings were superior to the 10-percent and 12-percent-thick wings from the standpoint of power economy during level flight for Mach numbers above 0.76. However, airplanes that are to fly at Mach numbers below 0.76 will gain aerodynamically if the percentage thickness of the wing and the aspect ratio are both increased. The lift-curve slopes for the 8-percent-thick wings at 0.85 Mach number were roughly twice their low-speed values.

Use of a pitot-static probe for determining wing section drag in flight at Mach numbers from 0.5 to approximately 1.0

NASA Technical Reports Server (NTRS)

Montoya, L. C.; Economu, M. A.; Cissell, R. E.

1974-01-01

The use of a pitot-static probe to determine wing section drag at speeds from Mach 0.5 to approximately 1.0 was evaluated in flight. The probe unit is described and operational problems are discussed. Typical wake profiles and wing section drag coefficients are presented. The data indicate that the pitot-static probe gave reliable results up to speeds of approximately 1.0.

A comparison of the structureborne and airborne paths for propfan interior noise

NASA Technical Reports Server (NTRS)

Eversman, W.; Koval, L. R.; Ramakrishnan, J. V.

1986-01-01

A comparison is made between the relative levels of aircraft interior noise related to structureborne and airborne paths for the same propeller source. A simple, but physically meaningful, model of the structure treats the fuselage interior as a rectangular cavity with five rigid walls. The sixth wall, the fuselage sidewall, is a stiffened panel. The wing is modeled as a simple beam carried into the fuselage by a large discrete stiffener representing the carry-through structure. The fuselage interior is represented by analytically-derived acoustic cavity modes and the entire structure is represented by structural modes derived from a finite element model. The noise source for structureborne noise is the unsteady lift generation on the wing due to the rotating trailing vortex system of the propeller. The airborne noise source is the acoustic field created by a propeller model consistent with the vortex representation. Comparisons are made on the basis of interior noise over a range of propeller rotational frequencies at a fixed thrust.

An Experimental Study of the Aerodynamics of a Swept and Unswept Semispan Wing with a Simulated Glaze Ice Accretion

NASA Technical Reports Server (NTRS)

Bragg, Michael B.

1994-01-01

Two semispan wings, one with a rectangular planform and one with 30 degrees of leading edge sweep were tested. Both had a NACA 0012 airfoil section, and both were tested clean and with simulated glaze ice shapes on their leading edges. Several surface roughness were tested. Each model geometry is documented and each surface roughness is explained. Aerodynamic performance of the wing in the form of sectional lift and integrated three-dimensional lift is documented through pressure measurements obtained from rows of surface pressure taps placed at five span locations on the wing. For the rectangular wing, sectional drag near the midspan is obtained from wake total pressure profiles. The data is presented in tabular and graphical form and is also available on computer disk.

An Iterative Decambering Approach for Post-Stall Prediction of Wing Characteristics using known Section Data

NASA Technical Reports Server (NTRS)

Mukherjee, Rinku; Gopalarathnam, Ashok; Kim, Sung Wan

2003-01-01

An iterative decambering approach for the post stall prediction of wings using known section data as inputs is presented. The method can currently be used for incompressible .ow and can be extended to compressible subsonic .ow using Mach number correction schemes. A detailed discussion of past work on this topic is presented first. Next, an overview of the decambering approach is presented and is illustrated by applying the approach to the prediction of the two-dimensional C(sub l) and C(sub m) curves for an airfoil. The implementation of the approach for iterative decambering of wing sections is then discussed. A novel feature of the current e.ort is the use of a multidimensional Newton iteration for taking into consideration the coupling between the di.erent sections of the wing. The approach lends itself to implementation in a variety of finite-wing analysis methods such as lifting-line theory, discrete-vortex Weissinger's method, and vortex lattice codes. Results are presented for a rectangular wing for a from 0 to 25 deg. The results are compared for both increasing and decreasing directions of a, and they show that a hysteresis loop can be predicted for post-stall angles of attack.

55. TOP (4TH) FLOOR OF 187380 WING LOOKING NORTH, WEST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

55. TOP (4TH) FLOOR OF 1873-80 WING LOOKING NORTH, WEST SIDE. NOTE SECTION, LEFT SIDE, MIDDLEGROUND, WHERE SMALL HIGH WINDOWS INDICATE POINT AT WHICH 1852 WING JOINS THIS WING. - Boston Manufacturing Company, 144-190 Moody Street, Waltham, Middlesex County, MA

LANN wing design

NASA Technical Reports Server (NTRS)

Firth, G. C.

1983-01-01

The LANN wing is the result of a joint effort between Lockheed, the Air Force, NASA, and the Netherlands to measure unsteady pressures at transonic speeds. It is a moderate-aspect-ratio transport wing configuration. The wing was machined from NITRONIC 40 and has 12 percent thick supercritical airfoil sections.

SOUTH WING, LOOKING NORTHEAST ALONG SOUTH SIDE, WEST SECTION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

SOUTH WING, LOOKING NORTHEAST ALONG SOUTH SIDE, WEST SECTION - Fort Sam Houston, San Antonio Quartermaster Depot, Northwest corner of New Braunfels Avenue & Grayson Street, San Antonio, Bexar County, TX

Wind-tunnel interference with particular reference to off-center positions of the wing and to the downwash at the tail

NASA Technical Reports Server (NTRS)

Silverstein, Abe; White, James A

1937-01-01

The theory of wind tunnel boundary influence on the downwash from a wing has been extended to provide more complete corrections for application to airplane test data. The first section of the report gives the corrections of the lifting line for wing positions above or below the tunnel center line; the second section shows the manner in which the induced boundary influence changes with distance aft of the lifting line. Values of the boundary corrections are given for off-center positions of the wing in circular, square, 2:1 rectangular, and 2:1 elliptical tunnels. Aft of the wing the corrections are presented for only the square and the 2:1 rectangular tunnels, but it is believed that these may be applied to jets of circular and 2:1 elliptical cross sections. In all cases results are included for both open and closed tunnels.

3. SOUTH WING, LOOKING NORTHEAST ALONG SOUTH SIDE, WEST SECTION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. SOUTH WING, LOOKING NORTHEAST ALONG SOUTH SIDE, WEST SECTION - Fort Sam Houston, San Antonio Quartermaster Depot, Northwest corner of New Braunfels Avenue & Grayson Street, San Antonio, Bexar County, TX

Detail of south wing south elevation wall section; camera facing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Detail of south wing south elevation wall section; camera facing northwest - Mare Island Naval Shipyard, Defense Electronics Equipment Operating Center, I Street, terminus west of Cedar Avenue, Vallejo, Solano County, CA

14 CFR 23.697 - Wing flap controls.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Wing flap controls. 23.697 Section 23.697... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap...

14 CFR 23.201 - Wings level stall.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wings level stall. 23.201 Section 23.201... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Stalls § 23.201 Wings level... airplane stalls. (b) The wings level stall characteristics must be demonstrated in flight as follows...

14 CFR 23.697 - Wing flap controls.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Wing flap controls. 23.697 Section 23.697...

14 CFR 23.697 - Wing flap controls.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Wing flap controls. 23.697 Section 23.697...

14 CFR 23.697 - Wing flap controls.

Code of Federal Regulations, 2014 CFR

2014-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Wing flap controls. 23.697 Section 23.697...

14 CFR 23.697 - Wing flap controls.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wing flap controls. 23.697 Section 23.697...

The transonic multi-foil Augmentor-Wing

NASA Technical Reports Server (NTRS)

Farbridge, J. E.; Smith, R. C.

1977-01-01

The paper describes the development of a transonic blown multi-foil Augmentor-Wing airfoil section that has a thickness/chord (t/c) value of 0.18. In comparison with an unblown single-foil supercritical section of the same overall t/c the new multi-foil section is characterized by an increased drag rise Mach number, increased buffet boundaries, and a reduction in 'effective' drag due to blowing. Potential advantages of the Augmentor-Wing are considered and the testing of three high-speed models in a trisonic pressurized wind tunnel (possessing a two-dimensional transonic insert) is discussed. The data indicate that a very thick wing is feasible since separations toward the rear of the main foil can be controlled both by shroud location and augmentor blowing.

An analysis of available data on effects of wing-fuselage-tail and wing-nacelle interference on the distribution of the air load among components of airplanes

NASA Technical Reports Server (NTRS)

Wollner, Bertram C

1949-01-01

Available information on the effects of wing-fuselage-tail and wing-nacelle interference on the distribution of the air load among components of airplanes is analyzed. The effects of wing and nacelle incidence, horizontal andvertical position of wing and nacelle, fuselage shape, wing section and filleting are considered. Where sufficient data were unavailable to determine the distribution of the air load, the change in lift caused by interference between wing and fuselage was found. This increment is affected to the greatest extent by vertical wing position.

Design and aerodynamic characteristics of a span morphing wing

NASA Astrophysics Data System (ADS)

Yu, Yuemin; Liu, Yanju; Leng, Jinsong

2009-03-01

Flight vehicles are often designed to function around a primary operating point such as an efficient cruise or a high maneuverability mode. Performance and efficiency deteriorate rapidly as the airplane moves towards other portions of the flight envelope. One solution to this quandary is to radically change the shape of the aircraft. This yields both improved efficiency and a larger flight envelope. This global shape change is an example of morphing aircraft . One concept of morphing is the span morphing wing in which the wingspan is varied to accommodate multiple flight regimes. This type of design allows for at least two discreet modes of the aircraft. The original configuration, in which the extensible portion of the wing is fully retracted, yields a high speed dash mode. Fully extending the wing provides the aircraft with a low speed mode tailored for fine tracking and loiter tasks. This paper discusses the design of a span morphing wing that permits a change in the aspect ratio while simultaneously supporting structural wing loads. The wing cross section is maintained by NACA 4412 rib sections . The span morphing wing was investigated in different configurations. The wing area and the aspect ratio of the span morphing wing increase as the wings pan increases. Computational aerodynamics are used to estimate the performance and dynamic characteristics of each wing shape of this span morphing wing as its wingspan is changed. Results show that in order to obtain the same lift, the conventional wing requires a larger angle of attach(AOA) than that of the span morphing wing.The lift of the span morphing wing increases as the wing span ,Mach number and AOA increases.

Applications of Ko Displacement Theory to the Deformed Shape Predictions of the Doubly-Tapered Ikhana Wing

NASA Technical Reports Server (NTRS)

Ko, William L.; Richards, W. Lance; Fleischer, Van Tran

2009-01-01

The Ko displacement theory, formulated for weak nonuniform (slowly changing cross sections) cantilever beams, was applied to the deformed shape analysis of the doubly-tapered wings of the Ikhana unmanned aircraft. The two-line strain-sensing system (along the wingspan) was used for sensing the bending strains needed for the wing-deformed shapes (deflections and cross-sectional twist) analysis. The deflection equation for each strain-sensing line was expressed in terms of the bending strains evaluated at multiple numbers of strain-sensing stations equally spaced along the strain-sensing line. For the preflight shape analysis of the Ikhana wing, the strain data needed for input to the displacement equations for the shape analysis were obtained from the nodal-stress output of the finite-element analysis. The wing deflections and cross-sectional twist angles calculated from the displacement equations were then compared with those computed from the finite-element computer program. The Ko displacement theory formulated for weak nonlinear cantilever beams was found to be highly accurate in the deformed shape predictions of the doubly-tapered Ikhana wing.

A Study of the Zero-Lift Drag-Rise Characteristics of Wing-Body Combinations Near the Speed of Sound

NASA Technical Reports Server (NTRS)

Whitcomb, Richard T

1956-01-01

Comparisons have been made of the shock phenomena and drag-rise increments for representative wing and central-body combinations with those for bodies of revolution having the same axial developments of cross-sectional areas normal to the airstream. On the basis of these comparisons, it is concluded that near the speed of sound the zero-lift drag rise of a low-aspect-ratio thin-wing and body combination is primarily dependent on the axial development of the cross-sectional areas normal to the airstream. It follows that the drag rise for any such configuration is approximately the same as that for any other with the same development of cross-sectional areas. Investigations have also been made of representative wing-body combinations with the body so indented that the axial developments of cross-sectional areas for the combinations were the same as that for the original body alone. Such indentations greatly reduced or eliminated the zero-lift drag-rise increments associated with the wings near the speed of sound.

Centurion in Flight over Lakebed with STS Mate-DeMate Device in Background

NASA Technical Reports Server (NTRS)

1998-01-01

The Centurion remotely piloted flying wing in flight during an initial series of low-altitude, battery-powered test flights in late 1998 at NASA's Dryden Flight Research Center, Edwards, California. The special Mate-DeMate structure used by NASA to attach Space Shuttle orbiters to the back of modified Boeing 747s for transport to other locations can be seen in the background of this photo. Centurion was a unique remotely piloted, solar-powered airplane developed under NASA's Environmental Research Aircraft and Sensor (ERAST) Program at the Dryden Flight Research Center, Edwards, California. Dryden joined with AeroVironment, Inc., Monrovia, California, under an ERAST Joint Sponsored Research Agreement, to design, develop, manufacture, and conduct flight development tests for the Centurion. The airplane was believed to be the first aircraft designed to achieve sustained horizontal flight at altitudes of 90,000 to 100,000 feet. Achieving this capability would meet the ERAST goal of developing an ultrahigh-altitude airplane that could meet the needs of the science community to perform upper-atmosphere environmental data missions. Much of the technology leading to the Centurion was developed during the Pathfinder and Pathfinder-Plus projects. However, in the course of its development, the Centurion became a prototype technology demonstration aircraft designed to validate the technology for the Helios, a planned future high-altitude, solar-powered aircraft that could fly for weeks or months at a time on science or telecommunications missions. Centurion had 206-foot-long wings and used batteries to supply power to the craft's 14 electric motors and electronic systems. Centurion first flew at Dryden Nov. 10, 1998, and followed up with a second test flight Nov. 19. On its third and final flight on Dec. 3, the craft was aloft for 31 minutes and reached an altitude of about 400 feet. All three flights were conducted over a section of Rogers Dry Lake adjacent to Dryden. For its third flight, the Centurion carried a simulated payload of more than 600 pounds--almost half the lightweight aircraft's empty weight. John Del Frate, Dryden's project manager for solar-powered aircraft, said he was impressed to see how well the aircraft handled the large weight increase from an initial payload of 150 pounds to one of 600 pounds. During 1999, Centurion gave way to the Helios Prototype, the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions. This was an enlarged version of the Centurion flying wing with a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of the solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved its lifting capability. This allows the Helios Prototype to carry a regenerative fuel-cell-based energy storage system that will enable flight at night, while still meeting the performance goals originally established for the Centurion.

The aerodynamic properties of thick aerofoils suitable for internal bracing

NASA Technical Reports Server (NTRS)

Norton, F H

1920-01-01

The object of this investigation was to determine the characteristics of various types of wings having sufficient depth to entirely inclose the wing bracing, and also to provide data for the further design of such sections. This type of wing is of interest because it eliminates the resistance of the interplane bracing, a portion of the airplane that sometimes absorbs one-quarter of the total power required to fly, and because these wings may be made to give a very high maximum lift. Results of the investigation of the following subjects are given: (1) effect of changing the upper and lower camber of thick aerofoils of uniform section; (2) effect of thickening the center and thinning the tips of a thin aerofoil; (3) effect of adding a convex lower surface to a tapered section; (4) effect of changing the mean thickness with constant center and tip sections; and (5) effect of varying the chord along the span.

XSECT: A computer code for generating fuselage cross sections - user's manual

NASA Technical Reports Server (NTRS)

Ames, K. R.

1982-01-01

A computer code, XSECT, has been developed to generate fuselage cross sections from a given area distribution and wing definition. The cross sections are generated to match the wing definition while conforming to the area requirement. An iterative procedure is used to generate each cross section. Fuselage area balancing may be included in this procedure if desired. The code is intended as an aid for engineers who must first design a wing under certain aerodynamic constraints and then design a fuselage for the wing such that the contraints remain satisfied. This report contains the information necessary for accessing and executing the code, which is written in FORTRAN to execute on the Cyber 170 series computers (NOS operating system) and produces graphical output for a Tektronix 4014 CRT. The LRC graphics software is used in combination with the interface between this software and the PLOT 10 software.

Leveraging Multi-Fidelity Models for Flexible Wing Systems

DTIC Science & Technology

2014-05-01

includes cataloging and defining of the various characteristics of insect wing morphology . His naming conventions of the venation are still in...J., 1992. Functional Morphology of Insect Wings. Annu. Rev. Entomol. 37, 113–140. doi:10.1146/annurev.en.37.010192.000553 Approved for public...FIGURES Figure Page Figure 1: Schematic illustration of a two-dimensional wing profile as a representative cross- section of an insect wing

Congressman Dave Weldon enjoys viewing the STS-97 launch

NASA Technical Reports Server (NTRS)

2000-01-01

Florida Congressman Dave Weldon enjoys the on-time launch of Space Shuttle Endeavour on the sixth construction flight to the International Space Station. Weldon and other guests of NASA viewed the launch from the Banana Creek VIP viewing site. Liftoff of Endeavour occurred at 10:06:01 p.m. EST. Endeavour is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to provide power to the Space Station. The 11-day mission includes two spacewalks to complete the solar array connections. Endeavour is expected to land Dec. 11 at 6:19 p.m. EST.

Transonic and Supersonic Wind-Tunnel Tests of Wing-Body Combinations Designed for High Efficiency at a Mach Number of 1.41

NASA Technical Reports Server (NTRS)

Grant, Frederick C.; Sevier, John R., Jr.

1960-01-01

Wind-tunnel force tests of a number of wing-body combinations designed for high lift-drag ratio at a Mach number of 1.41 are reported. Five wings and six bodies were used in making up the various wing-body combinations investigated. All the wings had the same highly swept dis- continuously tapered plan form with NACA 65A-series airfoil sections 4 percent thick at the root tapering linearly to 3 percent thick at the tip. The bodies were based on the area distribution of a Sears-Haack body of revolution for minimum drag with a given length and volume. These wings and bodies were used to determine the effects of wing twist., wing twist and camber, wing leading-edge droop, a change from circular to elliptical body cross-sectional shape, and body indentation by the area-rule and streamline methods. The supersonic test Mach numbers were 1.41 and 2.01. The transonic test Mach number range was from 0.6 to 1.2. For the transition-fixed condition and at a Reynolds number of 2.7 x 10(exp 6) based on the mean aerodynamic chord, the maximum value of lift- drag ratio at a Mach number of 1.41 was 9.6 for a combination with a twisted wing and an indented body of elliptical cross section. The tests indicated that the transonic rise in minimum drag was low and did not change appreciably up to the highest test Mach number of 2.01. The lower values of lift-drag ratio obtained at a Mach number of 2.01 can be attributed to the increase of drag due to lift with Mach number.

Induced drag ideal efficiency factor of arbitrary lateral-vertical wing forms

NASA Technical Reports Server (NTRS)

Deyoung, J.

1980-01-01

A relatively simple equation is presented for estimating the induced drag ideal efficiency factor e for arbitrary cross sectional wing forms. This equation is based on eight basic but varied wing configurations which have exact solutions. The e function which relates the basic wings is developed statistically and is a continuous function of configuration geometry. The basic wing configurations include boxwings shaped as a rectangle, ellipse, and diamond; the V-wing; end-plate wing; 90 degree cruciform; circle dumbbell; and biplane. Example applications of the e equations are made to many wing forms such as wings with struts which form partial span rectangle dumbbell wings; bowtie, cruciform, winglet, and fan wings; and multiwings. Derivations are presented in the appendices of exact closed form solutions found of e for the V-wing and 90 degree cruciform wing and for an asymptotic solution for multiwings.

Analysis of Mach number 0.8 turboprop slipstream wing/nacelle interactions

NASA Technical Reports Server (NTRS)

Welge, H. R.; Neuhart, D. H.; Dahlin, J. A.

1981-01-01

Data from wind tunnel tests of a powered propeller and nacelle mounted on a supercritical wing are analyzed. Installation of the nacelle significantly affected the wing flow and the flow on the upper surface of the wing is separated near the leading edge under powered conditions. Comparisons of various theories with the data indicated that the Neumann surface panel solution and the Jameson transonic solution gave results adequate for design purposes. A modified wing design was developed (Mod 3) which reduces the wing upper surface pressure coefficients and section lift coefficients at powered conditions to levels below those of the original wing without nacelle or power. A contoured over the wing nacelle that can be installed on the original wing without any appreciable interference to the wing upper surface pressure is described.

Teaching Physical Education in Elementary Schools. Sixth Edition.

ERIC Educational Resources Information Center

Vannier, Maryhelen; Gallahue, David L.

This source book of physical education activities for children from nursery school through the sixth grade covers five major areas of concern to the educator. Part one deals with the role of physical education in child development. The second section examines how children of different ages and abilities learn, discussing the preschool child, the…

DPW-VI Results Using FUN3D with Focus on k-kL-MEAH2015 (k-kL) Turbulence Model

NASA Technical Reports Server (NTRS)

Abdol-Hamid, K. S.; Carlson, Jan-Renee; Rumsey, Christopher L.; Lee-Rausch, Elizabeth M.; Park, Michael A.

2017-01-01

The Common Research Model wing-body configuration is investigated with the k-kL-MEAH2015 turbulence model implemented in FUN3D. This includes results presented at the Sixth Drag Prediction Workshop and additional results generated after the workshop with a nonlinear Quadratic Constitutive Relation (QCR) variant of the same turbulence model. The workshop provided grids are used, and a uniform grid refinement study is performed at the design condition. A large variation between results with and without a reconstruction limiter is exhibited on "medium" grid sizes, indicating that the medium grid size is too coarse for drawing conclusions in comparison with experiment. This variation is reduced with grid refinement. At a fixed angle of attack near design conditions, the QCR variant yielded decreased lift and drag compared with the linear eddy-viscosity model by an amount that was approximately constant with grid refinement. The k-kL-MEAH2015 turbulence model produced wing root junction flow behavior consistent with wind tunnel observations.

Static Performance of a Wing-Mounted Thrust Reverser Concept

NASA Technical Reports Server (NTRS)

Asbury, Scott C.; Yetter, Jeffrey A.

1998-01-01

An experimental investigation was conducted in the Jet-Exit Test Facility at NASA Langley Research Center to study the static aerodynamic performance of a wing-mounted thrust reverser concept applicable to subsonic transport aircraft. This innovative engine powered thrust reverser system is designed to utilize wing-mounted flow deflectors to produce aircraft deceleration forces. Testing was conducted using a 7.9%-scale exhaust system model with a fan-to-core bypass ratio of approximately 9.0, a supercritical left-hand wing section attached via a pylon, and wing-mounted flow deflectors attached to the wing section. Geometric variations of key design parameters investigated for the wing-mounted thrust reverser concept included flow deflector angle and chord length, deflector edge fences, and the yaw mount angle of the deflector system (normal to the engine centerline or parallel to the wing trailing edge). All tests were conducted with no external flow and high pressure air was used to simulate core and fan engine exhaust flows. Test results indicate that the wing-mounted thrust reverser concept can achieve overall thrust reverser effectiveness levels competitive with (parallel mount), or better than (normal mount) a conventional cascade thrust reverser system. By removing the thrust reverser system from the nacelle, the wing-mounted concept offers the nacelle designer more options for improving nacelle aero dynamics and propulsion-airframe integration, simplifying nacelle structural designs, reducing nacelle weight, and improving engine maintenance access.

Optimal redesign study of the harm wing

NASA Technical Reports Server (NTRS)

Mcintosh, S. C., Jr.; Weynand, M. E.

1984-01-01

The purpose of this project was to investigate the use of optimization techniques to improve the flutter margins of the HARM AGM-88A wing. The missile has four cruciform wings, located near mid-fuselage, that are actuated in pairs symmetrically and antisymmetrically to provide pitch, yaw, and roll control. The wings have a solid stainless steel forward section and a stainless steel crushed-honeycomb aft section. The wing restraint stiffness is dependent upon wing pitch amplitude and varies from a low value near neutral pitch attitude to a much higher value at off-neutral pitch attitudes, where aerodynamic loads lock out any free play in the control system. The most critical condition for flutter is the low-stiffness condition in which the wings are moved symmetrically. Although a tendency toward limit-cycle flutter is controlled in the current design by controller logic, wing redesign to improve this situation is attractive because it can be accomplished as a retrofit. In view of the exploratory nature of the study, it was decided to apply the optimization to a wing-only model, validated by comparison with results obtained by Texas Instruments (TI). Any wing designs that looked promising were to be evaluated at TI with more complicated models, including body modes. The optimization work was performed by McIntosh Structural Dynamics, Inc. (MSD) under a contract from TI.

Remote pivot decoupler pylon: Wing/store flutter suppressor

NASA Technical Reports Server (NTRS)

Hassler, J. M., Jr. (Inventor)

1986-01-01

A device for suspending a store from an aerodynamic support surface, such an an aircraft wing, and more specifically, for improving upon singlet pivot decoupler pylons by reducing both frequency of active store, alignment, and alignment system space and power requirements. Two links suspend a lower pylon/rack section and releasable attached store from an upper pylon section mounted under the wing. The links allow the lower pylon section to rotate in pitch about a remote pivot point. A leaf spring connected between the lower section and electrical alignment system servomechanism provides pitch alignment of the lower section/store combination. The servomechanism utilizes an electric servomotor to drive the gear train and reversibly move the leaf spring, thereby maintaining the pitch attitude of the store within acceptable limits. The damper strokes when the lower section rotates to damp large oscillations of store.

An investigation of tip planform influence on the aerodynamic load characteristics of semispan, upswept wing and wing-tip

NASA Technical Reports Server (NTRS)

Vanaken, Johannes M.

1986-01-01

A semi-span wing, equipped with an interchangeable tip, which was varied in planform and size was examined. Total wing aerodynamic loading was obtained from the wind tunnel scale system. The wing tip was mounted on a separate six-component strain gauge balance, which provided the aerodynamic loads on the tip. The tests were accomplished in the NASA Ames 7X10-Foot Wind Tunnel at a Mach number of 0.178. The aerodynamic load characteristics of the wing and of the tip were presented with the tip at several incidence angles relative to the wing inboard section.

Longitudinal aerodynamic characteristics of a generic fighter model with a wing designed for sustained transonic maneuver conditions

NASA Technical Reports Server (NTRS)

Ferris, J. C.

1986-01-01

A wind-tunnel investigation was made to determine the longitudinal aerodynamic characteristics of a fixed-wing generic fighter model with a wing designed for sustained transonic maneuver conditions. The airfoil sections on the wing were designed with a two-dimensional nonlinear computer code, and the root and tip section were modified with a three-dimensional code. The wing geometric characteristics were as follows: a leading-edge sweep of 45 degrees, a taper ratio of 0.2141, an aspect ratio of 3.30, and a thickness ratio of 0.044. The model was investigated at Mach numbers from 0.600 to 1.200, at Reynolds numbers, based on the model reference length, from 2,560,000 to 3,970,000, and through a model angle-of-attack range from -5 to +18 degrees.

Aircraft Configuration Study for Experimental 2-Place Aircraft and RPVs

DTIC Science & Technology

1990-03-01

area (sq. ft.) 84.24 82.86 Wing airfoil section Eppler Wing aspect ratio 8.09 Wing loading (GW) (lb./sq. ft.: 7.30 7.24 Canard span (ft.) 11.70 11.60...ESTIMATION FOR THE CANARD DRAG POLAR BUILDUP Aircraft Canard FG Input italicized data Wing for Eppler airfoil Cdmin = .0080 S = 82.9 Canard from Eppler ...DRAG POLAR BUILDUP Aircraft Canard FG Input italicized data Wing for Eppler airfoil Cdmin = .0080 S = 82.9 Canard from Eppler for GA(A)-1 airfoil Cdmin

33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.540 Section 334.540... enforced by the Commander, 45th Space Wing, Patrick Air Force Base, Florida and/or such persons or agencies... AND RESTRICTED AREA REGULATIONS § 334.540 Banana River at the Eastern Range, 45th Space Wing, Cape...

33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

Code of Federal Regulations, 2012 CFR

2012-07-01

..., 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.540 Section 334.540... enforced by the Commander, 45th Space Wing, Patrick Air Force Base, Florida and/or such persons or agencies... AND RESTRICTED AREA REGULATIONS § 334.540 Banana River at the Eastern Range, 45th Space Wing, Cape...

33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.540 Section 334.540... enforced by the Commander, 45th Space Wing, Patrick Air Force Base, Florida and/or such persons or agencies... AND RESTRICTED AREA REGULATIONS § 334.540 Banana River at the Eastern Range, 45th Space Wing, Cape...

33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

Code of Federal Regulations, 2010 CFR

2010-07-01

..., 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.540 Section 334.540... enforced by the Commander, 45th Space Wing, Patrick Air Force Base, Florida and/or such persons or agencies... AND RESTRICTED AREA REGULATIONS § 334.540 Banana River at the Eastern Range, 45th Space Wing, Cape...

33 CFR 334.540 - Banana River at the Eastern Range, 45th Space Wing, Cape Canaveral Air Force Station, FL...

Code of Federal Regulations, 2011 CFR

2011-07-01

..., 45th Space Wing, Cape Canaveral Air Force Station, FL; restricted area. 334.540 Section 334.540... enforced by the Commander, 45th Space Wing, Patrick Air Force Base, Florida and/or such persons or agencies... AND RESTRICTED AREA REGULATIONS § 334.540 Banana River at the Eastern Range, 45th Space Wing, Cape...

An Investigation of the Aerodynamic Characteristics of an Airplane Equipped with Several Different Sets of Wings

NASA Technical Reports Server (NTRS)

Crowley, J W , Jr; Green, M W

1929-01-01

This investigation was conducted by the National Advisory Committee for Aeronautics at Langley Field, Va., at the request of the Army Air Corps, for the purpose of comparing the full scale lift and drag characteristics of an airplane equipped with several sets of wings of commonly used airfoil sections. A Sperry Messenger Airplane with wings of R.A.F.-15, U.S.A.-5, U.S.A.-27, and Gottingen 387 airfoil sections was flown and the lift and drag characteristics of the airplane with each set of wings were determined by means of glide tests. The results are presented in tabular and curve form. (author)

Investigations at Supersonic Speeds of 22 Triangular Wings Representing Two Airfoil Sections for Each of 11 Apex Angles

NASA Technical Reports Server (NTRS)

Love, Eugene S

1955-01-01

The results of tests of 22 triangular wings, representing two leading-edge shapes for each of 11 apex angles, at Mach numbers 1.62, 1.92, and 1.40 are presented and compared with theory. All wings have a common thickness ratio of 8 percent and a common maximum-thickness point at 18 percent chord. Lift, drag, and pitching moment are given for all wings at each Mach number. The relation of transition in the boundary layer, shocks on the wing surfaces, and characteristics of the pressure distributions is discussed for several wings.

Utah Educational Quality Indicators. The Sixth in the Report Series: "How Good Are Utah Public Schools." Executive Summary.

ERIC Educational Resources Information Center

Nelson, David E.

For nearly 20 years, Utah's Office of Education has been systematically monitoring the academic performance and other characteristics of Utah's students. This executive summary, an overview of the sixth major report since 1967, examines several measures describing educational quality in Utah schools. The first section covers students' achievement…

THE NEGRO IN SCHOOLROOM LITERATURE, RESOURCE MATERIALS FOR THE TEACHER OF KINDERGARTEN THROUGH THE SIXTH GRADE. 2D ED.

ERIC Educational Resources Information Center

KOBLITZ, MINNIE W.

THIS ANNOTATED BIBLIOGRAPHY LISTS MORE THAN 250 BOOKS, CURRENT TO SEPTEMBER 1, 1966, WHICH CONTRIBUTE TO THE UNDERSTANDING AND APPRECIATION OF THE NEGRO HERITAGE. THESE RESOURCE MATERIALS, SUITABLE FOR STUDENTS IN KINDERGARTEN THROUGH SIXTH GRADE, ARE ARRANGED ACCORDING TO READING LEVEL. THERE ARE SECTIONS CONTAINING ADDITIONAL SOURCE MATERIALS…

Speed limits of aircraft

NASA Technical Reports Server (NTRS)

Everling, E

1923-01-01

This paper is restricted to the question of attainable speed limits and attacks the problem from different angles. Theoretical limits due to air resistance are presented along with design factors which may affect speed such as wing loads, wing areas, wing section shifting, landing speeds, drag-lift ratios, and power coefficients.

Analysis and design of planar and non-planar wings for induced drag minimization

NASA Technical Reports Server (NTRS)

Straussfogel, Dennis M.; Maughmer, Mark D.

1991-01-01

Improvements in the aerodynamic efficiency of commercial transport aircraft will reduce fuel usage with subsequent reduced cost, both monetary and environmental. To this end, the current research is aimed at reducing the overall drag of these aircraft with specific emphasis on reducing the drag generated by the lifting surfaces. The ultimate goal of this program is to create a wing design methodology which optimizes the geometry of the wing for lowest total drag within the constraints of a particular design specification. The components of drag which must be considered include profile drag, and wave drag. Profile drag is dependent upon, among other things, the airfoil section and the total wetted area. Induced drag, which is manifested as energy left in the wake by the trailing vortex system is mostly a function of wing span, but also depends on other geometric wing parameters. Wave drag of the wing, important in the transonic flight regime, is largely affected by the airfoil section, wing sweep, and so forth. The optimization problem is that of assessing the various parameters which contribute to the different components of wing drag, and determining the wing geometry which generates the best overall performance for a given aircraft mission. The primary thrust of the research effort to date was in the study of induced drag. Results from the study are presented.

Flapping Wings of an Inclined Stroke Angle: Experiments and Reduced-Order Models in Dual Aerial/Aquatic Flight

NASA Astrophysics Data System (ADS)

Izraelevitz, Jacob; Triantafyllou, Michael

2016-11-01

Flapping wings in nature demonstrate a large force actuation envelope, with capabilities beyond the limits of static airfoil section coefficients. Puffins, guillemots, and other auks particularly showcase this mechanism, as they are able to both generate both enough thrust to swim and lift to fly, using the same wing, by changing the wing motion trajectory. The wing trajectory is therefore an additional design criterion to be optimized along with traditional aircraft parameters, and could possibly enable dual aerial/aquatic flight. We showcase finite aspect-ratio flapping wing experiments, dynamic similarity arguments, and reduced-order models for predicting the performance of flapping wings that carry out complex motion trajectories.

Nonlinear Aerodynamics and the Design of Wing Tips

NASA Technical Reports Server (NTRS)

Kroo, Ilan

1991-01-01

The analysis and design of wing tips for fixed wing and rotary wing aircraft still remains part art, part science. Although the design of airfoil sections and basic planform geometry is well developed, the tip regions require more detailed consideration. This is important because of the strong impact of wing tip flow on wing drag; although the tip region constitutes a small portion of the wing, its effect on the drag can be significant. The induced drag of a wing is, for a given lift and speed, inversely proportional to the square of the wing span. Concepts are proposed as a means of reducing drag. Modern computational methods provide a tool for studying these issues in greater detail. The purpose of the current research program is to improve the understanding of the fundamental issues involved in the design of wing tips and to develop the range of computational and experimental tools needed for further study of these ideas.

Florida Governor Jeb Bush joins Daniel Goldin at KSC for STS-97 launch

NASA Technical Reports Server (NTRS)

2000-01-01

Florida's Governor Jeb Bush (center) joins NASA Administrator Daniel Goldin (right) for the launch of Space Shuttle Endeavour on mission STS-97. They viewed the launch from the Banana Creek VIP Site. Liftoff of Endeavour occurred on time at 10:06:01 p.m. EST with a crew of five. The sixth construction flight to the International Space Station, Endeavour is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to provide power to the Space Station. The 11-day mission includes two spacewalks to complete the solar array connections. Endeavour is expected to land Dec. 11 at 6:19 p.m. EST.

Florida Governor Jeb Bush joins Daniel Goldin at KSC for STS-97 launch

NASA Technical Reports Server (NTRS)

2000-01-01

Florida's Gov. Jeb Bush (left) joins NASA Administrator Daniel Goldin (right) for the launch of Space Shuttle Endeavour on mission STS-97. They viewed the launch from the Banana Creek VIP Site. Liftoff of Endeavour occurred on time at 10:06:01 p.m. EST with a crew of five. The sixth construction flight to the International Space Station, Endeavour is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to provide power to the Space Station. The 11-day mission includes two spacewalks to complete the solar array connections. Endeavour is expected to land Dec. 11 at 6:19 p.m. EST.

KSC-00pp1799

NASA Image and Video Library

2000-11-30

KENNEDY SPACE CENTER, FLA. -- Florida’s Gov. Jeb Bush (left) joins NASA Administrator Daniel Goldin (right) for the launch of Space Shuttle Endeavour on mission STS-97. They viewed the launch from the Banana Creek VIP Site. Liftoff of Endeavour occurred on time at 10:06:01 p.m. EST with a crew of five. The sixth construction flight to the International Space Station, Endeavour is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to provide power to the Space Station. The 11-day mission includes two spacewalks to complete the solar array connections. Endeavour is expected to land Dec. 11 at 6:19 p.m. EST

KSC00padig117

NASA Image and Video Library

2000-11-30

KENNEDY SPACE CENTER, FLA. -- Florida’s Governor Jeb Bush (center) joins NASA Administrator Daniel Goldin (right) for the launch of Space Shuttle Endeavour on mission STS-97. They viewed the launch from the Banana Creek VIP Site. Liftoff of Endeavour occurred on time at 10:06:01 p.m. EST with a crew of five. The sixth construction flight to the International Space Station, Endeavour is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to provide power to the Space Station. The 11-day mission includes two spacewalks to complete the solar array connections. Endeavour is expected to land Dec. 11 at 6:19 p.m. EST

KSC-00padig117

NASA Image and Video Library

2000-11-30

KENNEDY SPACE CENTER, FLA. -- Florida’s Governor Jeb Bush (center) joins NASA Administrator Daniel Goldin (right) for the launch of Space Shuttle Endeavour on mission STS-97. They viewed the launch from the Banana Creek VIP Site. Liftoff of Endeavour occurred on time at 10:06:01 p.m. EST with a crew of five. The sixth construction flight to the International Space Station, Endeavour is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to provide power to the Space Station. The 11-day mission includes two spacewalks to complete the solar array connections. Endeavour is expected to land Dec. 11 at 6:19 p.m. EST

KSC00pp1799

NASA Image and Video Library

2000-11-30

KENNEDY SPACE CENTER, FLA. -- Florida’s Gov. Jeb Bush (left) joins NASA Administrator Daniel Goldin (right) for the launch of Space Shuttle Endeavour on mission STS-97. They viewed the launch from the Banana Creek VIP Site. Liftoff of Endeavour occurred on time at 10:06:01 p.m. EST with a crew of five. The sixth construction flight to the International Space Station, Endeavour is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to provide power to the Space Station. The 11-day mission includes two spacewalks to complete the solar array connections. Endeavour is expected to land Dec. 11 at 6:19 p.m. EST

The development of a capability for aerodynamic testing of large-scale wing sections in a simulated natural rain environment

NASA Technical Reports Server (NTRS)

Bezos, Gaudy M.; Cambell, Bryan A.; Melson, W. Edward

1989-01-01

A research technique to obtain large-scale aerodynamic data in a simulated natural rain environment has been developed. A 10-ft chord NACA 64-210 wing section wing section equipped with leading-edge and trailing-edge high-lift devices was tested as part of a program to determine the effect of highly-concentrated, short-duration rainfall on airplane performance. Preliminary dry aerodynamic data are presented for the high-lift configuration at a velocity of 100 knots and an angle of attack of 18 deg. Also, data are presented on rainfield uniformity and rainfall concentration intensity levels obtained during the calibration of the rain simulation system.

A structural dynamics study of a wing-pylon-tiltrotor system

NASA Astrophysics Data System (ADS)

Khader, N.; Abu-Mallouh, R.

1992-12-01

A simple structural model for a three-bladed tiltrotor-pylon-wing assembly is presented, which accounts for chordwise, transverse, and torsional wing deformations, rigid pylon pitching motion with respect to the wing tip cross-section in its deformed position, lead-lag, flap, and torsional deformations of rotor blades. The model considers equivalent viscous damping associated with blade and wing elastic deformations and with rigid pylon pitching motion. It is established that blade-to wing bending rigidity ratio, pylon pitching frequency, equivalent viscous damping associated with blade elastic deformations, and rotational speed, are the most important design parameters, whose effect on system frequencies and stability boundaries is evaluated.

Proceedings of the Sixth Conference on African Linguistics. Working Papers in Linguistics, No. 20.

ERIC Educational Resources Information Center

Herbert, Robert K., Ed.

This volume contains a selection of 27 papers presented at the Sixth Conference on African Linguistics. The papers cover a very wide range of topics, and are organized into three sections: (1) Historical and Comparative Studies; (2) Phonology; and (3) Syntax. The conference program, the program of the symposium on African language, culture and…

Prevalence of breast-feeding and exclusive breast-feeding at 48 h after birth and up to the sixth month in Cyprus: the BrEaST start in life project.

PubMed

Economou, Mary; Kolokotroni, Ourania; Paphiti-Demetriou, Irene; Kouta, Christiana; Lambrinou, Ekaterini; Hadjigeorgiou, Eleni; Hadjiona, Vasiliki; Tryfonos, Froso; Philippou, Elena; Middleton, Nicos

2018-04-01

To assess the prevalence and sociodemographic determinants of breast-feeding (BF) and exclusive breast-feeding (EBF) in Cyprus up to the sixth month. Cross-sectional and longitudinal descriptive study. BF and EBF were estimated based on mothers' self-reported BF status in line with Step 7 of the WHO/UNICEF Baby-Friendly Hospital Initiative questionnaire and based on 24 h recall. Maternity wards in all public hospitals and twenty-nine (of thirty-five) private maternity clinics nationwide. Consecutive sample of 586 mothers recruited within 48 h from birth, followed up by telephone interview at the first, fourth and sixth month. Although 84·3 % of mothers initiated BF before discharge, prevalence of BF at the sixth month was 32·4 %, with the highest reduction observed between the first and fourth months. Prevalence of EBF at 48 h was 18·8 % and fell gradually to 5·0 % at the sixth month. Mothers with higher educational attainment or higher family income were more likely to breast-feed until the sixth month. In terms of EBF, an association was observed only with education, which persisted until the sixth month. Other than social gradient, mode of delivery was the strongest determinant of BF initiation, exclusivity and continuation. Mothers who gave birth vaginally were three to four times more likely to initiate BF (OR=3·1; 95 % CI 1·7, 5·4) and EBF (OR=4·3; 95 % CI 2·7, 6·8). The low prevalence of BF and EBF in Cyprus, together with the fact that caesarean section rates are currently among the highest in Europe, suggest the need for further research to understand this multidimensional phenomenon and for interdisciplinary policy action to protect, promote and support BF.

Experimental aerodynamic characteristics for slender bodies with thin wings and tail at angles of attack from 0 deg to 58 deg and Mach numbers from 0.6 to 2.0

NASA Technical Reports Server (NTRS)

Jorgensen, L. H.; Nelson, E. R.

1976-01-01

An experimental investigation was conducted by wind tunnel to measure the static aerodynamic characteristics for bodies of circular and elliptic cross section with various thin flat plate wings and a thin tail consisting of horizontal and vertical parts. The wings had aspect ratios of 4 and taper ratios of about 0, 0.25, and 0.5. Two additional wings, which had taper ratios near 0.25 and aspect ratios of about 3 and 5, were also tested in combination with the bodies and tail. All wings had about the same planform area. The exposed area of the horizontal portion of the tail was about 33 to 36 percent of the exposed area of the wings. The exposed area of the vertical tail fin was about 22 to 24 percent of the exposed area of the wings. The elliptic body, with an a/b = 2 cross section, had the same length and axial distribution of cross sectional area as the circular body. The circular body had a cylindrical aftersection of fineness ratio 7, and it was tested with the wings and tail in combination with tangent ogive noses that had fineness ratios of 2.5, 3.0, 3.5, and 5.0. In addition, an ogive nose with a rounded tip and an ogive nose with two different nose strake arrangements were used. Nineteen configuration combinations were tested at Mach numbers of 0.6, 0.9, 1.5, and 2.0 at angles of attack from 0 to 58 deg. The Reynolds numbers, based on body base diameter, were about 4.3 X 100,000.

Multirate flutter suppression system design for the Benchmark Active Controls Technology Wing

NASA Technical Reports Server (NTRS)

Berg, Martin C.; Mason, Gregory S.

1994-01-01

To study the effectiveness of various control system design methodologies, the NASA Langley Research Center initiated the Benchmark Active Controls Project. In this project, the various methodologies will be applied to design a flutter suppression system for the Benchmark Active Controls Technology (BACT) Wing (also called the PAPA wing). Eventually, the designs will be implemented in hardware and tested on the BACT wing in a wind tunnel. This report describes a project at the University of Washington to design a multirate flutter suppression system for the BACT wing. The objective of the project was two fold. First, to develop a methodology for designing robust multirate compensators, and second, to demonstrate the methodology by applying it to the design of a multirate flutter suppression system for the BACT wing. The contributions of this project are (1) development of an algorithm for synthesizing robust low order multirate control laws (the algorithm is capable of synthesizing a single compensator which stabilizes both the nominal plant and multiple plant perturbations; (2) development of a multirate design methodology, and supporting software, for modeling, analyzing and synthesizing multirate compensators; and (3) design of a multirate flutter suppression system for NASA's BACT wing which satisfies the specified design criteria. This report describes each of these contributions in detail. Section 2.0 discusses our design methodology. Section 3.0 details the results of our multirate flutter suppression system design for the BACT wing. Finally, Section 4.0 presents our conclusions and suggestions for future research. The body of the report focuses primarily on the results. The associated theoretical background appears in the three technical papers that are included as Attachments 1-3. Attachment 4 is a user's manual for the software that is key to our design methodology.

Integrated Experimental and Numerical Research on the Aerodynamics of Unsteady Moving Aircraft

DTIC Science & Technology

2007-06-01

blended wing body configuration were tested in different modes of oscillatory motions roll, pitch and yaw as well as delta wing geometries like X-31...airplane configurations (e.g. wide body, green aircraft, blended wing body) the approach up to now using semi-empirical methods as standard...cross section wing. In order to evaluate the influence of individual components of the tested airplane configuration, such as winglets , vertical or

Investigation of Wing Characteristics at a Mach Number of 1.53 II : Swept Wings of Taper Ratio 0.5

NASA Technical Reports Server (NTRS)

Vincenti, Walter G; Van Dyke, Milton D; Matteson, Frederick H

1948-01-01

Measured values of lift, drag, and pitching moment at M(sub o) = 1.53 are presented for seven wings varying in sweep angle from 60 degrees sweepforward to 60 degrees sweepback. All wings had a cambered, double-wedge section 5-percent thick and a common taper ratio of 0.5. The experimental results are compared with the predictions of the linear theory.

Store Separation Simulation of the Penguin Missile from Helicopters

DTIC Science & Technology

2006-05-01

Fin Sections – Parent Aircraft Aerodynamic Modeling • Fuselage • Wing and Pylon – Flight Simulation Features • Eqns. Of Motion • Ejectors , Thrust ...model – Lanyard model – Models for ejectors , thrust , mass, etc… – Helicopter rotor wake model – Penguin wing deployment dynamics – Penguin wing roll...umbilical, wing roll tabs, time dependent thrust and mass properties, and the incorporation of a realistic autopilot. The modeling of the unique

Determination and classification of the aerodynamic properties of wing sections

NASA Technical Reports Server (NTRS)

Munk, Max M

1925-01-01

The following note, prepared for the NACA, contains several remarks on the possible improvement of the experimental determination of the aerodynamic properties of wing sections. It shows how errors of observation can subsequently be partially eliminated, and how the computation of the maxima or minima of aerodynamic characteristics can be much improved.

Summary of Drag Characteristics of Practical-Construction Wing Sections

NASA Technical Reports Server (NTRS)

Quinn, John H , Jr

1948-01-01

The effect of several parameters on the drag characteristics of practical-construction wing sections have been considered and evaluated. The effects considered were those of surface roughness, surface waviness, compressive load, and de-icers. The data were obtained from a number of tests in the Langley two-dimensional low-turbulence tunnels.

Wind-tunnel Tests of the Fowler Variable-area Wing

NASA Technical Reports Server (NTRS)

Weick, Fred E; Platt, Robert C

1932-01-01

The lift, drag, and center of pressure characteristics of a model of the Fowler variable-area wing were measured in the NACA 7 by 10 foot wind tunnel. The Fowler wing consists of a combination of a main wing and an extension surface, also of airfoil section. The extension surface can be entirely retracted within the lower rear portion of the main wing or it can be moved to the rear and downward. The tests were made with the nose of the extension airfoil in various positions near the trailing edge of the main wing and with the surface at various angular deflections. The highest lift coefficient obtained was C(sub L) = 3.17 as compared with 1.27 for the main wing alone.

Micro-Scale Flapping Wings for the Advancement of Flying MEMS

DTIC Science & Technology

2009-03-01

section. As air strikes the airfoil, it is divided over and under the wing. The airfoil is curved in a manner such that the air passing over the wing moves...This table briefly describes the L-edit layout of Figure A.1. MUMPS Run 82 Micromirrors Mirrors fabricated to EENG 636 specifications Thermal

Design and demonstration of a small expandable morphing wing

NASA Astrophysics Data System (ADS)

Heryawan, Yudi; Park, Hoon C.; Goo, Nam S.; Yoon, Kwang J.; Byun, Yung H.

2005-05-01

In this paper, we present design, manufacturing, and wind tunnel test for a small-scale expandable morphing wing. The wing is separated into inner and outer wings as a typical bird wing. The part from leading edge of the wing chord is made of carbon composite strip and balsa. The remaining part is covered with curved thin carbon fiber composite mimicking wing feathers. The expandable wing is driven by a small DC motor, reduction gear, and fiber reinforced composite linkages. Rotation of the motor is switched to push-pull linear motion by a screw and the linear motion of the screw is transferred to linkages to create wing expansion and folding motions. The wing can change its aspect ratio from 4.7 to 8.5 in about 2 seconds and the speed can be controlled. Two LIPCAs (Lightweight Piezo-Composite Actuators) are attached under the inner wing section and activated on the expanded wing state to modify camber of the wing. In the wind tunnel test, change of lift, drag, and pitching moment during wing expansion have been investigated for various angles of attack. The LIPCA activation has created significant additional lift.

Aircraft

DOEpatents

Hibbs, B.D.; Lissaman, P.B.S.; Morgan, W.R.; Radkey, R.L.

1998-09-22

This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gases for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well. 31 figs.

Systems Engineering and Information Science in Health Screening

ERIC Educational Resources Information Center

Hall, William A.

1969-01-01

Presented before the combined sessions of the Section on Administration and the Section on Clinical Medicine, American College Health Association, Forty-sixth Annual Meeting, Minneapolis, Minnestoa, May 3, 1968.

Structural Concepts Study of Non-circular Fuselage Configurations

NASA Technical Reports Server (NTRS)

Mukhopadhyay, Vivel

1996-01-01

A preliminary study of structural concepts for noncircular fuselage configurations is presented. For an unconventional flying-wing type aircraft, in which the fuselage is inside the wing, multiple fuselage bays with non-circular sections need to be considered. In a conventional circular fuselage section, internal pressure is carried efficiently by a thin skin via hoop tension. If the section is non-circular, internal pressure loads also induce large bending stresses. The structure must also withstand additional bending and compression loads from aerodynamic and gravitational forces. Flat and vaulted shell structural configurations for such an unconventional, non-circular pressurized fuselage of a large flying-wing were studied. A deep honeycomb sandwich-shell and a ribbed double-wall shell construction were considered. Combinations of these structural concepts were analyzed using both analytical and simple finite element models of isolated sections for a comparative conceptual study. Weight, stress, and deflection results were compared to identify a suitable configuration for detailed analyses. The flat sandwich-shell concept was found preferable to the vaulted shell concept due to its superior buckling stiffness. Vaulted double-skin ribbed shell configurations were found to be superior due to their weight savings, load diffusion, and fail-safe features. The vaulted double-skin ribbed shell structure concept was also analyzed for an integrated wing-fuselage finite element model. Additional problem areas such as wing-fuselage junction and pressure-bearing spar were identified.

The Impact of Technology on the Enactment of "Inquiry" in a Technology Enthusiast's Sixth Grade Science Classroom

ERIC Educational Resources Information Center

Waight, Noemi; Abd-El-Khalick, Fouad

2007-01-01

This study investigated the impact of the use of computer technology on the enactment of "inquiry" in a sixth grade science classroom. Participants were 42 students (38% female) enrolled in two sections of the classroom and taught by a technology-enthusiast instructor. Data were collected over the course of 4 months during which several "inquiry"…

Lecture notes in economics and mathematical system. Volume 150: Supercritical wing sections 3

NASA Technical Reports Server (NTRS)

Bauer, F.; Garabedian, P.; Korn, D.

1977-01-01

Application of computational fluid dynamics to the design and analysis of supercritical wing sections is discussed. Computer programs used to study the flight of modern aircraft at high subsonic speeds are listed and described. The cascades of shockless transonic airfoils that are expected to increase the efficiency of compressors and turbines are included.

Properties of oscillating refractive optical wings with one reflective surface

NASA Astrophysics Data System (ADS)

Artusio-Glimpse, Alexandra B.; Swartzlander, Grover A.

2013-09-01

A new modality for optical micromanipulation is under investigation. Optical wings are shaped refractive objects that experience a force and torque owing to the reflection and transmission of uniform light at the object surface. We present wing designs that provide a restoring torque that returns the wing to a source facing orientation while preserving efficient thrust from radiation pressure. The torsional stiffness and orbital period of a set of optical wing cross-sectional shapes are determined from numerical ray-tracing analyses. These results demonstrate the potential to develop an efficient optomechanical device for applications in microbiology and space flight systems.

Theoretical antisymmetric span loading for wings of arbitrary plan form at subsonic speeds

NASA Technical Reports Server (NTRS)

Deyoung, John

1951-01-01

A simplified lifting-surface theory that includes effects of compressibility and spanwise variation of section lift-curve slope is used to provide charts with which antisymmetric loading due to arbitrary antisymmetric angle of attack can be found for wings having symmetric plan forms with a constant spanwise sweep angle of the quarter-chord line. Consideration is given to the flexible wing in roll. Aerodynamic characteristics due to rolling, deflected ailerons, and sideslip of wings with dihedral are considered. Solutions are presented for straight-tapered wings for a range of swept plan forms.

Classical Aerodynamic Theory

NASA Technical Reports Server (NTRS)

Jones, R. T. (Compiler)

1979-01-01

A collection of papers on modern theoretical aerodynamics is presented. Included are theories of incompressible potential flow and research on the aerodynamic forces on wing and wing sections of aircraft and on airship hulls.

Development of direct-inverse 3-D methods for applied transonic aerodynamic wing design and analysis

NASA Technical Reports Server (NTRS)

Carlson, Leland A.

1989-01-01

An inverse wing design method was developed around an existing transonic wing analysis code. The original analysis code, TAWFIVE, has as its core the numerical potential flow solver, FLO30, developed by Jameson and Caughey. Features of the analysis code include a finite-volume formulation; wing and fuselage fitted, curvilinear grid mesh; and a viscous boundary layer correction that also accounts for viscous wake thickness and curvature. The development of the inverse methods as an extension of previous methods existing for design in Cartesian coordinates is presented. Results are shown for inviscid wing design cases in super-critical flow regimes. The test cases selected also demonstrate the versatility of the design method in designing an entire wing or discontinuous sections of a wing.

A CFD Database for Airfoils and Wings at Post-Stall Angles of Attack

NASA Technical Reports Server (NTRS)

Petrilli, Justin; Paul, Ryan; Gopalarathnam, Ashok; Frink, Neal T.

2013-01-01

This paper presents selected results from an ongoing effort to develop an aerodynamic database from Reynolds-Averaged Navier-Stokes (RANS) computational analysis of airfoils and wings at stall and post-stall angles of attack. The data obtained from this effort will be used for validation and refinement of a low-order post-stall prediction method developed at NCSU, and to fill existing gaps in high angle of attack data in the literature. Such data could have potential applications in post-stall flight dynamics, helicopter aerodynamics and wind turbine aerodynamics. An overview of the NASA TetrUSS CFD package used for the RANS computational approach is presented. Detailed results for three airfoils are presented to compare their stall and post-stall behavior. The results for finite wings at stall and post-stall conditions focus on the effects of taper-ratio and sweep angle, with particular attention to whether the sectional flows can be approximated using two-dimensional flow over a stalled airfoil. While this approximation seems reasonable for unswept wings even at post-stall conditions, significant spanwise flow on stalled swept wings preclude the use of two-dimensional data to model sectional flows on swept wings. Thus, further effort is needed in low-order aerodynamic modeling of swept wings at stalled conditions.

Shape control of structures with semi-definite stiffness matrices for adaptive wings

NASA Astrophysics Data System (ADS)

Austin, Fred; Van Nostrand, William C.; Rossi, Michael J.

1993-09-01

Maintaining an optimum-wing cross section during transonic cruise can dramatically reduce the shock-induced drag and can result in significant fuel savings and increased range. Our adaptive-wing concept employs actuators as truss elements of active ribs to reshape the wing cross section by deforming the structure. In our previous work, to derive the shape control- system gain matrix, we developed a procedure that requires the inverse of the stiffness matrix of the structure without the actuators. However, this method cannot be applied to designs where the actuators are required structural elements since the stiffness matrices are singular when the actuator are removed. Consequently, a new method was developed, where the order of the problem is reduced and only the inverse of a small nonsingular partition of the stiffness matrix is required to obtain the desired gain matrix. The procedure was experimentally validated by achieving desired shapes of a physical model of an aircraft-wing rib. The theory and test results are presented.

Theoretical study of nonadiabatic boundary-layer stabilization times in a cryogenic wind tunnel for typical stainless steel wing and fuselage models

NASA Technical Reports Server (NTRS)

Johnson, C. B.

1980-01-01

The time varying effect of nonadiabatic wall conditions on boundary layer properties was studied for a two dimensional wing section and an axisymmetric fuselage. The wing and fuselage sections are representative of the wing root chord and fuselage of a typical transport model for the National Transonic Facility. The analysis was made with a solid wing and three fuselage configurations (one solid and two hollow with varying skin thicknesses) all made from AISI type 310S stainless steel. The displacement thickness and local skin friction were investigated at a station on the model in terms of the time required for these two boundary layer properties to reach an adiabatic wall condition after a 50 K step change in total temperature. The analysis was made for a free stream Mach number of 0.85, a total temperature of 117 K, and stagnation pressures of 2, 6, and 9 atm.

Thermostructural Analysis of Unconventional Wing Structures of a Hyper-X Hypersonic Flight Research Vehicle for the Mach 7 Mission

NASA Technical Reports Server (NTRS)

Ko, William L.; Gong, Leslie

2001-01-01

Heat transfer, thermal stresses, and thermal buckling analyses were performed on the unconventional wing structures of a Hyper-X hypersonic flight research vehicle (designated as X-43) subjected to nominal Mach 7 aerodynamic heating. A wing midspan cross section was selected for the heat transfer and thermal stress analyses. Thermal buckling analysis was performed on three regions of the wing skin (lower or upper); 1) a fore wing panel, 2) an aft wing panel, and 3) a unit panel at the middle of the aft wing panel. A fourth thermal buckling analysis was performed on a midspan wing segment. The unit panel region is identified as the potential thermal buckling initiation zone. Therefore, thermal buckling analysis of the Hyper-X wing panels could be reduced to the thermal buckling analysis of that unit panel. "Buckling temperature magnification factors" were established. Structural temperature-time histories are presented. The results show that the concerns of shear failure at wing and spar welded sites, and of thermal buckling of Hyper-X wing panels, may not arise under Mach 7 conditions.

Aircraft wing structural detail design (wing, aileron, flaps, and subsystems)

NASA Technical Reports Server (NTRS)

Downs, Robert; Zable, Mike; Hughes, James; Heiser, Terry; Adrian, Kenneth

1993-01-01

The goal of this project was to design, in detail, the wing, flaps, and ailerons for a primary flight trainer. Integrated in this design are provisions for the fuel system, the electrical system, and the fuselage/cabin carry-through interface structure. This conceptual design displays the general arrangement of all major components in the wing structure, taking into consideration the requirements set forth by the appropriate sections of Federal Aviation Regulation Part 23 (FAR23) as well as those established in the statement of work.

Wind-tunnel investigation of effect of interference on lateral-stability characteristics of four NACA 23012 wings, an elliptical and a circular fuselage and vertical fins

NASA Technical Reports Server (NTRS)

House, Rufus O; Wallace, Arthur R

1941-01-01

Report presents the results of a wind-tunnel investigation of the effect of wing-fuselage interference on lateral-stability characteristics made in the NACA 7 by 10-foot wind tunnel on four fuselages and two fins, representing high-wing, low-wing, and midwing monoplanes. The fuselages are of circular and elliptical cross section. The wings have rounded tips and, in plan form, one is rectangular and the three are tapered 3:1 with various amounts of sweep. The rate of change in the coefficients of rolling moment, yawing moment, and lateral force with angle of yaw is given in a form to show the increment caused by wing-fuselage interference for the model with no fin and the effect of wing-fuselage interference on fin effectiveness. Results for the fuselage-fin combination and the wing tested alone are also given.

On the leading edge vortex of thin wings

NASA Astrophysics Data System (ADS)

Arredondo, Abel; Viola, Ignazio Maria

2016-11-01

On thin wings, the sharp leading edge triggers laminar separation followed by reattachment, forming a Leading Edge Vortex (LEV). This flow feature is of paramount importance because, if periodically shed, it leads to large amplitude load fluctuations, while if stably attached to the wing, it can provide lift augmentation. We found that on asymmetric-spinnaker-type yacht sails, the LEV can be stable despite the relatively low sweep (30°). This finding, which was recently predicted numerically by Viola et al., has been confirmed through current flume tests on a 1:115th model scale sail. Forces were measured and Particle Image Velocimetry was performed on four horizontal sail sections at a Reynolds number of 1.7x104. Vortex detection revealed that the LEV becomes progressively larger and more stable towards the highest sections, where its axis has a smaller angle with respect to the freestream velocity. Mapping the sail section on a rotating cylinder through a Joukowski transformation, we quantified the lift augmentation provided by the LEV on each sail section. These results open up new sail design strategies based on the manipulation of the LEV and can be applicable to the wings of unmanned aerial vehicles and underwater vehicles. Project funded by Conacyt.

Reentry heating analysis of space shuttle with comparison of flight data

NASA Technical Reports Server (NTRS)

Gong, L.; Quinn, R. D.; Ko, W. L.

1982-01-01

Surface heating rates and surface temperatures for a space shuttle reentry profile were calculated for two wing cross sections and one fuselage cross section. Heating rates and temperatures at 12 locations on the wing and 6 locations on the fuselage are presented. The heating on the lower wing was most severe, with peak temperatures reaching values of 1240 C for turbulent flow and 900 C for laminar flow. For the fuselage, the most severe heating occured on the lower glove surface where peak temperatures of 910 C and 700 C were calculated for turbulent flow and laminar flow, respectively. Aluminum structural temperatures were calculated using a finite difference thermal analyzer computer program, and the predicted temperatures are compared to measured flight data. Skin temperatures measured on the lower surface of the wing and bay 1 of the upper surface of the wing agreed best with temperatures calculated assuming laminar flow. The measured temperatures at bays two and four on the upper surface of the wing were in quite good agreement with the temperatures calculated assuming separated flow. The measured temperatures on the lower forward spar cap of bay four were in good agreement with values predicted assuming laminar flow.

Reynolds number effects on the aerodynamic characteristics of irregular planform wings at Mach number 0.3. [in the Ames 12 ft pressure wind tunnel

NASA Technical Reports Server (NTRS)

Kruse, R. L.; Lovette, G. H.; Spencer, B., Jr.

1977-01-01

The subsonic aerodynamic characteristics of a series of irregular planform wings were studied in wind tunnel tests conducted at M = 0.3 over a range of Reynolds numbers from 1.6 million to 26 million/m. The five basic wing planforms varied from a trapezoidal to a delta shape. Leading edge extensions, added to the basic shape, varied in approximately 5 deg increments from the wing leading edge sweep-back angle to a maximum 80 deg. Most of the tests were conducted using an NACA 0008 airfoil section with grit boundary layer trips. Tests were also conducted using an NACA 0012 airfoil section and an 8% thick wedge. In addition, the effect of free transition (no grit) was investigated. A body was used on all models.

Static shape control for adaptive wings

NASA Astrophysics Data System (ADS)

Austin, Fred; Rossi, Michael J.; van Nostrand, William; Knowles, Gareth; Jameson, Antony

1994-09-01

A theoretical method was developed and experimentally validated, to control the static shape of flexible structures by employing internal translational actuators. A finite element model of the structure, without the actuators present, is employed to obtain the multiple-input, multiple-output control-system gain matrices for actuator-load control as well as actuator-displacement control. The method is applied to the quasistatic problem of maintaining an optimum-wing cross section during various transonic-cruise flight conditions to obtain significant reductions in the shock-induced drag. Only small, potentially achievable, adaptive modifications to the profile are required. The adaptive-wing concept employs actuators as truss elements of active ribs to reshape the wing cross section by deforming the structure. Finite element analyses of an adaptive-rib model verify the controlled-structure theory. Experiments on the model were conducted, and arbitrarily selected deformed shapes were accurately achieved.

Theoretical study of aerodynamic characteristics of wings having vortex flow

NASA Technical Reports Server (NTRS)

Reddy, C. S.

1979-01-01

The aerodynamic characteristics of slender wings having separation induced vortex flows are investigated by employing three different computer codes--free vortex sheet, quasi vortex lattice, and suction analogy methods. Their capabilities and limitations are examined, and modifications are discussed. Flat wings of different configurations: arrow, delta, and diamond shapes, as well as cambered delta wings, are studied. The effect of notch ratio on the load distributions and the longitudinal characteristics of a family of arrow and diamond wings is explored. The sectional lift coefficients and the accumulated span loadings are determined for an arrow wing and are seen to be unusual in comparison with the attached flow results. The theoretically predicted results are compared with the existing experimental values.

Wing planform effects at supersonic speeds for an advanced fighter configuration

NASA Technical Reports Server (NTRS)

Wood, R. M.; Miller, D. S.

1984-01-01

Four advanced fighter configurations, which differed in wing planform and airfoil shape, were investigated in the Langley Unitary Plan Wind Tunnel at Mach numbers of 1.60, 1.80, 2.00, and 2.16. Supersonic data were obtained on the four uncambered wings, which were each attached to a single fighter fuselage. The fuselage geometry varied in cross-sectional shape and had two side-mounted, flow-through, half-axisymmetric inlets. Twin vertical tails were attached to the fuselage. The four planforms tested were a 65 deg delta wing, a combination of a 20 deg trapezoidal wing and a 45 deg horizontal tail, a 70 deg/30 deg cranked wing, and a 70 deg/66 deg crank wing, where the angle values refer to the leading-edge sweep angle of the lifting-surface planform. Planform effects on a single fuselage representative of an advanced fighter aircraft were studied. Results show that the highly swept cranked wings exceeded the aerodynamic performance levels, at low lift coefficients, of the 65 deg delta wing and the 20 deg trapezoidal wing at trimmed and untrimmed conditions.

Investigation at Mach Numbers of 0.20 to 3.50 of Blended Wing-Body Combinations of Sonic Design with Diamond, Delta, and Arrow Plan Forms

NASA Technical Reports Server (NTRS)

Holdaway, George H.; Mellenthin, Jack A.

1960-01-01

The models had aspect-ratio-2 diamond, delta, and arrow wings with the leading edges swept 45.00 deg, 59.04 deg, and 70.82 deg, respectively. The wing sections were computed by varying the section shape along with the body radii (blending process) to match the prescribed area distribution and wing plan form. The wing sections had an average value of maximum thickness ratio of about 4 percent of the local chords in a streamwise direction. The models were tested with transition fixed at Reynolds numbers of about 4,000,000 to 9,000,0000, based on the mean aerodynamic chord of the wings. The effect of varying Reynolds number was checked at both subsonic and supersonic speeds. The diamond model was superior to the other plan forms at transonic speeds ((L/D)max = 11.00 to 9.52) because of its higher lift-curve slope and near optimum wave drag due to the blending process. For the wing thickness tested with the diamond model, the marked body and wing contouring required for transonic conditions resulted in a large wave-drag penalty at the higher supersonic Mach numbers where the leading and trailing edges of the wing were supersonic. Because of the low sweep of the trailing edge of the delta model, this configuration was less adaptable to the blending process. Removing a body bump prescribed by the Mach number 1.00 design resulted in a good supersonic design. This delta model with 10 percent less volume was superior to the other plan forms at Mach numbers of 1.55 to 2.35 ((L/D)max = 8.65 to 7.24), but it and the arrow model were equally good at Mach numbers of 2.50 to 3.50 ((L/D)max - 6.85 to O.39). At transonic speeds the arrow model was inferior because of the reduced lift-curve slope associated with its increased sweep and also because of the wing base drag. The wing base-drag coefficients of the arrow model based on the wing planform area decreased from a peak value of 0.0029 at Mach number 1.55 to 0.0003 at Mach number 3.50. Linear supersonic theory was satisfactory for predicting the aerodynamic trends at Mach numbers from 1.55 to 3.50 of lift-curve slope, wave drag, drag due to lift, aerodynamic-center location, and maximum lift-drag ratios for each of the models.

A Survey of English Sixth Formers' Knowledge of Early Brain Development.

PubMed

Nolan, Mary

2017-10-01

Objectives To ascertain the knowledge of young people aged 16 to 19 of early brain development and their attitudes towards the care of babies and preschool children. Design Cross-sectional, school- and college-based survey including all sixth form students present on the days of data collection. The survey instrument comprised forced-choice questions in four sections: Demographics, Perceptions and Understanding of Early Childhood Development, Parental Behaviors to Support Early Brain development, and Resource Needs and Usage. Setting Two sixth form schools and one sixth form college in three towns of varying affluence in the West Midlands of the United Kingdom. Method The survey was mounted online and completed by 905 students who returned it directly to the researcher. Results Most students knew that tobacco, alcohol, and drugs are hazardous in pregnancy, and many recognized the impact of maternal stress on fetal brain development. Many believed that babies can be "spoiled" and did not appreciate the importance of reading to babies and of the relationship between play and early brain development. A significant minority thought that physical activity and a healthy diet have little impact on young children's development. Respondents said they would turn firstly to their parents for advice on baby care rather than professionals. Conclusion Young people need educating about parenting activities that support the all-round healthy development of infants. The importance of a healthy diet, physical activity, reading, and play should be included in sixth form curricula and antenatal classes. Consideration should be given to educating grandparents because of their influence on new parents.

Sensitivity Analysis of Wing Aeroelastic Responses

NASA Technical Reports Server (NTRS)

Issac, Jason Cherian

1995-01-01

Design for prevention of aeroelastic instability (that is, the critical speeds leading to aeroelastic instability lie outside the operating range) is an integral part of the wing design process. Availability of the sensitivity derivatives of the various critical speeds with respect to shape parameters of the wing could be very useful to a designer in the initial design phase, when several design changes are made and the shape of the final configuration is not yet frozen. These derivatives are also indispensable for a gradient-based optimization with aeroelastic constraints. In this study, flutter characteristic of a typical section in subsonic compressible flow is examined using a state-space unsteady aerodynamic representation. The sensitivity of the flutter speed of the typical section with respect to its mass and stiffness parameters, namely, mass ratio, static unbalance, radius of gyration, bending frequency, and torsional frequency is calculated analytically. A strip theory formulation is newly developed to represent the unsteady aerodynamic forces on a wing. This is coupled with an equivalent plate structural model and solved as an eigenvalue problem to determine the critical speed of the wing. Flutter analysis of the wing is also carried out using a lifting-surface subsonic kernel function aerodynamic theory (FAST) and an equivalent plate structural model. Finite element modeling of the wing is done using NASTRAN so that wing structures made of spars and ribs and top and bottom wing skins could be analyzed. The free vibration modes of the wing obtained from NASTRAN are input into FAST to compute the flutter speed. An equivalent plate model which incorporates first-order shear deformation theory is then examined so it can be used to model thick wings, where shear deformations are important. The sensitivity of natural frequencies to changes in shape parameters is obtained using ADIFOR. A simple optimization effort is made towards obtaining a minimum weight design of the wing, subject to flutter constraints, lift requirement constraints for level flight and side constraints on the planform parameters of the wing using the IMSL subroutine NCONG, which uses successive quadratic programming.

Use of a pitot probe for determining wing section drag in flight

NASA Technical Reports Server (NTRS)

Saltzman, E. J.

1975-01-01

A wake traversing probe was used to obtain section drag and wake profile data from the wing of a sailplane. The transducer sensed total pressure defect in the wake as well as freestream total pressure on both sides of the sensing element when the probe moved beyond the wake. Profiles of wake total pressure defects plotted as a function of distance above and below the trailing edge plane were averaged for calculating section drag coefficients for flights at low dynamic pressures.

Aircraft

DOEpatents

Hibbs, Bart D.; Lissaman, Peter B. S.; Morgan, Walter R.; Radkey, Robert L.

1998-01-01

This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gasses for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well.

Reduction of the RCS of the leading edge of a conducting wing-shaped structure by means of lossless dielectric material

NASA Astrophysics Data System (ADS)

Booysen, A. J.; Pistorius, C. W. I.; Malherbe, J. A. G.

1991-06-01

The radar cross section of the leading edge of a conducting wing-shaped structure is reduced by replacing part of the structure with a lossless dielectric material. The structure retains its original external shape, thereby ensuring that the aerodynamic properties are not altered by the structural changes needed to reduce the radar cross section.

Wind-Tunnel Investigation of the Horizontal Motion of a Wing Near the Ground

NASA Technical Reports Server (NTRS)

Serebrisky, Y. M.; Biachuev, S. A.

1946-01-01

By the method of images the horizontal steady motion of a wing at small heights above the ground was investigated in the wind tunnel, A rectangular wing with Clark Y-H profile was tested with and without flaps. The distance from the trailing edge of the wing to the ground was varied within the limits 0.75 less than or = s/c less than or = 0.25. Measurements were made of the lift, the drag, the pitching moment, and the pressure distribution at one section. For a wing without flaps and one with flaps a considereble decrease in the lift force and a,drop in the drag was obtained at angles of attack below stalling. The flow separation near the ground occurs at smaller angles of attack than is the case for a great height above the ground. At horizontal steady flight for practical values of the height above the ground the maximum lift coefficient for the wing without flaps changes little, but markedly decreases for the wing with flaps. Analysis of these phenomena involves the investigation of the pressure distribution. The pressure distribution curves showed that the changes occurring near the ground are not equivalent to a change in the angle of attack. At the lower surface of the section a very strong increase in the pressures is observed. The pressure changes on the upper surface at angles of attack below stalling are insignificant and lead mainly to an increase in the unfavorable pressure gradient, resulting in the earlier occurrence of separation. For a wing with flaps at large angles of attack for distances from the trailing edge of the flap to the ground less than 0.5 chord, the flow between the wing end the ground is retarded so greatly that the pressure coefficient at the lower surface of the section is very near its limiting value (P = 1), and any further possibility of increase in the pressure is very small. In the application an approximate computation procedure is given of the change of certain aerodynamic characteristics for horizontal steady flight near the ground.

An Investigation of Wing and Aileron Loads Due to Deflected Inboard and Outboard Ailerons on a 4-Percent-Thick 30 deg Sweptback Wing at Transonic Speeds

NASA Technical Reports Server (NTRS)

Whitcomb, Charles F.; Critzos, Chris C.; Brown, Philippa F.

1961-01-01

An investigation has been conducted in the Langley 16-foot transonic tunnel to determine the changes in wing loading characteristics due to deflections of a plain faired flap-type inboard aileron, a plain faired flap-type outboard aileron, and a slab-sided thickened trailing edge outboard aileron. The test wing was 4 percent thick and had 30 sweep of the quarter chord, an aspect ratio of 3.0, a taper ratio of 0.2, and NACA 65A004 airfoil sections. The loading characteristics of the deflected ailerons were also investigated. The model was a sting-mounted wing-body combination, and pressure measurements over one wing panel (exposed area) and the ailerons were obtained for angles of attack from 0 to 20 at deflections up to +/- 15 deg for Mach numbers between 0.80 and 1.03. The test Reynolds number based on the wing mean aerodynamic chord was about 7.4 x 10(exp 6). The results of the investigation indicated that positive deflection of the plain faired flap-type inboard aileron caused significant added loading over the wing sections outboard of the aileron at all Mach numbers for model angles of attack from 0 deg or 4 deg up to 12 deg. Positive deflection of the two outboard ailerons (plain faired and slab sided with thickened trailing edge) caused significant added loading over the wing sections inboard of the ailerons for different model angle-of-attack ranges at the several test Mach numbers. The loading shapes over the ailerons were irregular and would be difficult to predict from theoretical considerations in the transonic speed range. The longitudinal and lateral center-of-pressure locations for the ailerons varied only slightly with increasing angle of attack and/or Mach number. Generally, the negative slopes of the variations of aileron hinge-moment coefficient with aileron deflection for all three ailerons varied similarly with Mach number at the test angles of attack.

High-Reynolds-Number Test of a 5-Percent-Thick Low-Aspect-Ratio Semispan Wing in the Langley 0.3-Meter Transonic Cryogenic Tunnel: Wing Pressure Distributions

NASA Technical Reports Server (NTRS)

Chu, Julio; Lawing, Pierce L.

1990-01-01

A high Reynolds number test of a 5 percent thick low aspect ratio semispan wing was conducted in the adaptive wall test section of the Langley 0.3 m Transonic Cryogenic Tunnel. The model tested had a planform and a NACA 64A-105 airfoil section that is similar to that of the pressure instrumented canard on the X-29 experimental aircraft. Chordwise pressure data for Mach numbers of 0.3, 0.7, and 0.9 were measured for an angle-of-attack range of -4 to 15 deg. The associated Reynolds numbers, based on the geometric mean chord, encompass most of the flight regime of the canard. This test was a free transition investigation. A summary of the wing pressures are presented without analysis as well as adapted test section top and bottom wall pressure signatures. However, the presented graphical data indicate Reynolds number dependent complex leading edge separation phenomena. This data set supplements the existing high Reynolds number database and are useful for computational codes comparison.

Transonic flow theory of airfoils and wings

NASA Technical Reports Server (NTRS)

Garabedian, P. R.

1976-01-01

There are plans to use the supercritical wing on the next generation of commercial aircraft so as to economize on fuel consumption by reducing drag. Computer codes have served well in meeting the consequent demand for new wing sections. The possibility of replacing wind tunnel tests by computational fluid dynamics is discussed. Another approach to the supercritical wing is through shockless airfoils. A novel boundary value problem in the hodograph plane is studied that enables one to design a shockless airfoil so that its pressure distribution very nearly takes on data that are prescribed.

An experimental comparative study of the efficiency of twisted and flat flapping wings during hovering flight.

PubMed

Phan, Hoang Vu; Truong, Quang Tri; Park, Hoon Cheol

2017-04-19

This work presents a parametric study to find a proper wing configuration for achieving economical flight using unsteady blade element theory, which is based on the 3D kinematics of a flapping wing. Power loading was first considered as a performance parameter for the study. The power loadings at each wing section along the wingspan were obtained for various geometric angles of attack (AoAs) by calculating the ratios of the vertical forces generated and the power consumed by that particular wing section. The results revealed that the power loading of a negatively twisted wing could be higher than the power loading that a flat wing can have; the power loading of the negatively twisted wing was approximately 5.9% higher. Given the relatively low average geometric AoA (α A,root   ≈  44° and α A,tip   ≈  25°), the vertical force produced by the twisted wing for the highest power loading was approximately 24.4% less than that produced by the twisted wing for the strongest vertical force. Therefore, for a given wing geometry and flapping amplitude, a flapping-wing micro air vehicle required a 13.5% increase in flapping frequency to generate the same strongest cycle-average vertical force while saving about 24.3% power. However, when force 3 /power 2 and force 2 /power ratios were considered as performance indices, the twisted wings for the highest force 3 /power 2 (α A,root   ≈  43° and α A,tip   ≈  30°) and force 2 /power (α A,root   ≈  43° and α A,tip   ≈  36°) required only 6.5% and 4% increases in flapping frequency and consumed 26.2% and 25.3% less power, respectively. Thus, it is preferable to use a flapping wing operating at a high frequency using the geometric AoAs for the highest power loading, force 3 /power 2 ratio, and force 2 /power ratio over a flapping wing operating at a low frequency using a high geometric AoA with the strongest vertical force. Additionally, by considering both aerodynamic and inertial forces, this study obtained average geometric AoAs in the range of 30° to 40°, which are similar to those of a typical hovering insect's wings. Therefore, the operation of an aerodynamically uneconomical, high AoA in a hovering insect's wings during flight is explainable.

Constraints on the wing morphology of pterosaurs

PubMed Central

Palmer, Colin; Dyke, Gareth

2012-01-01

Animals that fly must be able to do so over a huge range of aerodynamic conditions, determined by weather, wind speed and the nature of their environment. No single parameter can be used to determine—let alone measure—optimum flight performance as it relates to wing shape. Reconstructing the wings of the extinct pterosaurs has therefore proved especially problematic: these Mesozoic flying reptiles had a soft-tissue membranous flight surface that is rarely preserved in the fossil record. Here, we review basic mechanical and aerodynamic constraints that influenced the wing shape of pterosaurs, and, building on this, present a series of theoretical modelling results. These results allow us to predict the most likely wing shapes that could have been employed by these ancient reptiles, and further show that a combination of anterior sweep and a reflexed proximal wing section provides an aerodynamically balanced and efficient theoretical pterosaur wing shape, with clear benefits for their flight stability. PMID:21957137

Active control using control allocation for UAVs with seamless morphing wing

NASA Astrophysics Data System (ADS)

Wang, Zheng-jie; Sun, Yin-di; Yang, Da-qing; Guo, Shi-jun

2012-04-01

In this paper, a small seamless morphing wing aircraft of MTOW=51 kg is investigated. The leading edge (LE) and trailing edge (TE) control surfaces are positioned in the wing section in span wise. Based on the studying results of aeroelastic wing characteristics, the controller should be designed depending on the flight speed. Compared with a wing of rigid hinged aileron, the morphing wing produces the rolling moment by deflecting the flexible TE and LE surfaces. An iteration method of pseudo-inverse allocation and quadratic programming allocation within the constraints of actuators have be investigated to solve the nonlinear control allocation caused by the aerodynamics of the effectors. The simulation results will show that the control method based on control allocation can achieve the control target.

Active control using control allocation for UAVs with seamless morphing wing

NASA Astrophysics Data System (ADS)

Wang, Zheng-jie; Sun, Yin-di; Yang, Da-qing; Guo, Shi-jun

2011-11-01

In this paper, a small seamless morphing wing aircraft of MTOW=51 kg is investigated. The leading edge (LE) and trailing edge (TE) control surfaces are positioned in the wing section in span wise. Based on the studying results of aeroelastic wing characteristics, the controller should be designed depending on the flight speed. Compared with a wing of rigid hinged aileron, the morphing wing produces the rolling moment by deflecting the flexible TE and LE surfaces. An iteration method of pseudo-inverse allocation and quadratic programming allocation within the constraints of actuators have be investigated to solve the nonlinear control allocation caused by the aerodynamics of the effectors. The simulation results will show that the control method based on control allocation can achieve the control target.

Pressure distributions on a rectangular aspect-ratio-6, slotted supercritical airfoil wing with externally blown flaps

NASA Technical Reports Server (NTRS)

Johnson, W. G., Jr.

1976-01-01

An investigation was made in the 5.18 m (17 ft) test section of the Langley 300 MPH 7 by 10 foot tunnel on a rectangular, aspect ratio 6 wing which had a slotted supercritical airfoil section and externally blown flaps. The 13 percent thick wing was fitted with two high lift flap systems: single slotted and double slotted. The designations single slotted and double slotted do not include the slot which exists near the trailing edge of the basic slotted supercritical airfoil. Tests were made over an angle of attack range of -6 deg to 20 deg and a thrust-coefficient range up to 1.94 for a free-stream dynamic pressure of 526.7 Pa (11.0 lb/sq ft). The results of the investigation are presented as curves and tabulations of the chordwise pressure distributions at the midsemispan station for the wing and each flap element.

Large and Small Droplet Impingement Data on Airfoils and Two Simulated Ice Shapes

NASA Technical Reports Server (NTRS)

Papadakis, Michael; Wong, See-Cheuk; Rachman, Arief; Hung, Kuohsing E.; Vu, Giao T.; Bidwell, Colin S.

2007-01-01

Water droplet impingement data were obtained at the NASA Glenn Icing Research Tunnel (IRT) for four wings and one wing with two simulated ice shapes. The wings tested include three 36-in. chord wings (MS(1)-317, GLC-305, and a NACA 652-415) and a 57-in. chord Twin Otter horizontal tail section. The simulated ice shapes were 22.5- and 45-min glaze ice shapes for the Twin Otter horizontal tail section generated using the LEWICE 2.2 ice accretion program. The impingement experiments were performed with spray clouds having median volumetric diameters of 11, 21, 79, 137, and 168 mm. Comparisons to the experimental data were generated which showed good agreement for the clean wings and ice shapes at lower drop sizes. For larger drop sizes LEWICE 2.2 over predicted the collection efficiencies due to droplet splashing effects which were not modeled in the program. Also for the more complex glaze ice shapes interpolation errors resulted in the over prediction of collection efficiencies in cove and shadow regions of ice shapes.

Airfoil section characteristics as applied to the prediction of air forces and their distribution on wings

NASA Technical Reports Server (NTRS)

Jacobs, Eastman N; Rhode, R V

1938-01-01

The results of previous reports dealing with airfoil section characteristics and span load distribution data are coordinated into a method for determining the air forces and their distribution on airplane wings. Formulas are given from which the resultant force distribution may be combined to find the wing aerodynamic center and pitching moment. The force distribution may also be resolved to determine the distribution of chord and beam components. The forces are resolved in such a manner that it is unnecessary to take the induced drag into account. An illustration of the method is given for a monoplane and a biplane for the conditions of steady flight and a sharp-edge gust. The force determination is completed by outlining a procedure for finding the distribution of load along the chord of airfoil sections.

Investigation of Full-Scale Split Trailing-Edge Wing Flaps with Various Chords and Hinge Locations

NASA Technical Reports Server (NTRS)

Wallace, Rudolf

1936-01-01

This report gives the results of an investigation conducted in the NACA full-scale wind tunnel on a small parasol monoplane equipped with three different split trailing-edge wing flaps. The object of the investigation was to determine and correlate data on the characteristics of the airplane and flaps as affected by variation in flap chord, flap deflection, and flap location along the wing chord. The results give the lift, the drag, and the pitching moment characteristics of the airplane, and the flap forces and moments, the pressure distribution over the flaps and wing at one section, and the downwash characteristics of the flap and wing combinations.

A Survey of Factors Affecting Blunt Leading-Edge Separation for Swept and Semi-Slender Wings

NASA Technical Reports Server (NTRS)

Luckring, James M.

2010-01-01

A survey is presented of factors affecting blunt leading-edge separation for swept and semi-slender wings. This class of separation often results in the onset and progression of separation-induced vortical flow over a slender or semi-slender wing. The term semi-slender is used to distinguish wings with moderate sweeps and aspect ratios from the more traditional highly-swept, low-aspect-ratio slender wing. Emphasis is divided between a selection of results obtained through literature survey a section of results from some recent research projects primarily being coordinated through NATO s Research and Technology Organization (RTO). An aircraft context to these studies is included.

Interatomic potentials for Cd, Zn, and Hg from absorption spectra

NASA Astrophysics Data System (ADS)

Su, Ching-Hua; Liao, Pok-Kai; Huang, Yu; Liou, Shian-Shyang; Brebrick, R. F.

1984-07-01

The absorption coefficient has been measured over a 65 nm range in the red wing of the 213.8 nm line for Zn vapor at 1000 °C. It has also been measured in the blue wing and over a 60 nm range in the red wing of the 228.7 nm line for Cd vapor at five temperatures between 642 and 955 °C and over a 75 nm range in the red wing of the 253.7 nm line for Hg vapor at five temperatures between 460 and 860 °C. These data are analyzed in terms of the statistical theory of broadening. Oscillator strengths of 1.42±0.01 and 1.61±0.06 are obtained for, respectively, the Cd line and the Zn line. Pair potentials for both the ground and lowest excited state are also obtained in all three cases. For Cd this is done assuming no functional form and then assuming Lennard-Jones potentials. Both methods agree and give a ground state minimum of -47.5 meV at 0.482 nm separation and an excited state minimum of -1.06 eV at 0.410 nm. A functional form is required for the less extensive Zn data and the Lennard-Jones form leads to a range of possibilities including ground and excited state minima of -56 meV at 0.400 nm and -1.30 eV at 0.330 nm, respectively, which are in fair agreement with the theoretical calculations. For Hg the experiments indicate a single excited state and a ground state with a minimum of -55 meV. Assuming no functional form for the pair potentials, taking the excited state as doubly degenerate, and assuming the transition probability from the ground to excited state is one-sixth of the free atom value gives points along the ground and excited state potentials that join smoothly with other experimental results and agree well with the calculation of Baylis for the ground state.

Transonic Aerodynamic Characteristics of a Wing-Body Combination having a 52.5 deg Sweptback Wing of Aspect Ratio 3 with Conical Camber and Designed for a Mach Number of the Square Root of 2

NASA Technical Reports Server (NTRS)

Igoe, William B.; Re, Richard J.; Cassetti, Marlowe

1961-01-01

An investigation has been made of the effects of conical wing camber and supersonic body indentation on the aerodynamic characteristics of a wing-body configuration at transonic speeds. Wing aspect ratio was 3.0, taper ratio was 0.1, and quarter-chord line sweepback was 52.5 deg with airfoil sections of 0.03 thickness ratio. The tests were conducted in the Langley 16-foot transonic tunnel at various Mach numbers from 0.80 to 1.05 at angles of attack from -4 deg to 14 deg. The cambered-wing configuration achieved higher lift-drag ratios than a similar plane-wing configuration. The camber also reduced the effects of wing-tip flow separation on the aerodynamic characteristics. In general, no stability or trim changes below wing-tip flow separation resulted from the use of camber. The use of supersonic body indentation improved the lift-drag ratios at Mach numbers from 0.96 to 1.05.

Externally blown flap noise research

NASA Technical Reports Server (NTRS)

Dorsch, R. G.

1974-01-01

The Lewis Research Center cold-flow model externally blown flap (EBF) noise research test program is summarized. Both engine under-the-wing and over-the-wing EBF wing section configurations were studied. Ten large scale and nineteen small scale EBF models were tested. A limited number of forward airspeed effect and flap noise suppression tests were also run. The key results and conclusions drawn from the flap noise tests are summarized and discussed.

Design Improvement for Airplane-Engine Nacelles

NASA Technical Reports Server (NTRS)

Vernon, D. F.; Page, G. S.; Welge, H. R.

1987-01-01

Advanced three-dimensional transonic design routine for wingmounted engine nacelles modified to include effects of propellers and wing sweep. Resulting new nacelle shapes introduce less airflow disturbance and less drag. Improvement consists of introduction of boundary conditions in form of nonuniform onset flow in area of wing washed by propeller slipstream. Routine generates nacelle shape as series of cross sections swept, relatively to unperturbed flow, as function of wing shape.

Testing and Analysis of a Composite Non-Cylindrical Aircraft Fuselage Structure . Part II; Severe Damage

NASA Technical Reports Server (NTRS)

Przekop, Adam; Jegley, Dawn C.; Lovejoy, Andrew E.; Rouse, Marshall; Wu, Hsi-Yung T.

2016-01-01

The Environmentally Responsible Aviation Project aimed to develop aircraft technologies enabling significant fuel burn and community noise reductions. Small incremental changes to the conventional metallic alloy-based 'tube and wing' configuration were not sufficient to achieve the desired metrics. One airframe concept identified by the project as having the potential to dramatically improve aircraft performance was a composite-based hybrid wing body configuration. Such a concept, however, presented inherent challenges stemming from, among other factors, the necessity to transfer wing loads through the entire center fuselage section which accommodates a pressurized cabin confined by flat or nearly flat panels. This paper discusses a finite element analysis and the testing of a large-scale hybrid wing body center section structure developed and constructed to demonstrate that the Pultruded Rod Stitched Efficient Unitized Structure concept can meet these challenging demands of the next generation airframes. Part II of the paper considers the final test to failure of the test article in the presence of an intentionally inflicted severe discrete source damage under the wing up-bending loading condition. Finite element analysis results are compared with measurements acquired during the test and demonstrate that the hybrid wing body test article was able to redistribute and support the required design loads in a severely damaged condition.

Wind-tunnel measurements of the chordwise pressure distribution and profile drag of a research airplane model incorporating a 17-percent-thick supercritical wing

NASA Technical Reports Server (NTRS)

Ferris, J. C.

1973-01-01

The Langley 8-foot transonic pressure tunnel to determine the wing chordwise pressure distribution for a 0.09-scale model of a research airplane incorporating a 17-percent-thick supercritical wing. Airfoil profile drag was determined from wake pressure measurements at the 42-percent-semispan wing station. The investigation was conducted at Mach numbers from 0.30 to 0.80 over an angle-of-attack range sufficient to include buffet onset. The Reynolds number based on the mean geometric chord varied from 2 x 10 to the 6th power at Mach number 0.30 to 3.33 x 10 to the 6th power at Mach number 0.65 and was maintained at a constant value of 3.86 x 10 to the 6th power at Mach numbers from 0.70 to 0.80. Pressure coefficients for four wing semispan stations and wing-section normal-force and pitching-moment coefficients for two semispan stations are presented in tabular form over the Mach number range from 0.30 to 0.80. Plotted chordwise pressure distributions and wake profiles are given for a selected range of section normal-force coefficients over the same Mach number range.

CFD based aerodynamic modeling to study flight dynamics of a flapping wing micro air vehicle

NASA Astrophysics Data System (ADS)

Rege, Alok Ashok

The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV's, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate representation of aerodynamic forces and moments. The research is divided into two sections. In the first section, derivation of the nonlinear dynamics of flapping wing micro air vehicles is presented. The flapping wing micro air vehicle (MAV) used in this research is modeled as a system of three rigid bodies: a body and two wings. The design is based on an insect called Drosophila Melanogaster, commonly known as fruit-fly. The mass and inertial effects of the wing on the body are neglected for the present work. The nonlinear dynamics is simulated with the aerodynamic data published in the open literature. The flapping frequency is used as the control input. Simulations are run for different cases of wing positions and the chosen parameters are studied for boundedness. Results show a qualitative inconsistency in boundedness for some cases, and demand a better aerodynamic data. The second part of research involves preliminary work required to generate new aerodynamic data for the nonlinear model. First, a computational mesh is created over a 2-D wing section of the MAV model. A finite volume based computational flow solver is used to test different flapping trajectories of the wing section. Finally, a parametric study of the results obtained from the tests is performed.

The aerodynamic characteristics of seven frequently used wing sections at full Reynolds number

NASA Technical Reports Server (NTRS)

Munk, Max M; Miller, Elton W

1927-01-01

This report contains the aerodynamic properties of the wing sections U.S.A. 5, U.S.A. 27, U.S.A. 35 A, U.S.A. 35 B, Clark Y, R.A.F. 15, and Gottingen 387, as determined at various Reynolds numbers up to an approximately full scale value in the variable density wind tunnel of the National Advisory Committee for Aeronautics. It is shown that the characteristics of the wings investigated are affected greatly and in a somewhat erratic manner by variation of the Reynolds number. In general there is a small increase in maximum lift and an appreciable decrease in drag at all lifts.

Cross-Sectional and Longitudinal Relations among Peer-Reported Trustworthiness, Social Relationships, and Psychological Adjustment in Children and Early Adolescents from the United Kingdom and Canada

ERIC Educational Resources Information Center

Rotenberg, Ken J.; McDougall, Patricia; Boulton, Michael J.; Vaillancourt, Tracy; Fox, Claire; Hymel, Shelley

2004-01-01

Trustworthiness was examined in children and early adolescents from two countries. In Study 1,505 children in the fifth and sixth school years in the United Kingdom (mean age = 9 years 7 months) were tested across an 8-month period. In Study 2,350 sixth- through eighth-grade Canadian children and early adolescents (mean age = 12 years 11 months)…

Pressure distribution on a 1- by 3-meter semispan wing at sweep angles from 0 deg to 40 deg in subsonic flow

NASA Technical Reports Server (NTRS)

Yip, L. P.; Shubert, G. L.

1976-01-01

A 1- by 3-meter semispan wing of taper ratio 1.0 with NACA 0012 airfoil section contours was tested in the Langley V/STOL tunnel to measure the pressure distribution at five sweep angles, 0 deg, 10 deg, 20 deg, 30 deg, and 40 deg, through an angle-of-attack range from -6 deg to 20 deg. The pressure data are presented as plots of pressure coefficients at each static-pressure tap location on the wing. Flow visualization wing-tuft photographs are also presented for a wing of 40 deg sweep. A comparison between theory and experiment using two inviscid theories and a viscous theory shows good agreement for pressure distributions, normal forces, and pitching moments for the wing at 0 deg sweep.

Pressure distributions on a cambered wing body configuration at subsonic Mach numbers

NASA Technical Reports Server (NTRS)

Henderson, W. P.

1975-01-01

An investigation was conducted in the Langley high-speed 7- by 10-foot tunnel at Mach numbers of 0.20 and 0.40 and angles of attack up to about 22 deg to measure the pressure distributions on two cambered-wing configurations. The wings had the same planform (aspect ratio of 2.5 and a leading-edge-sweep angle of 44 deg) but differed in amounts of camber and twist (wing design lift coefficient of 0.35 and 0.70). The effects of wing strake on the wing pressure distributions were also studied. The results indicate that the experimental chordwise pressure distribution agrees reasonably well with the design distribution over the forward 60 percent of nearly all the airfoil sections for the lower cambered wing. The measured lifting pressures are slightly less than the design pressures over the aft part of the airfoil. For the highly cambered wing, there is a significant difference between the experimental and the design pressure level. The experimental distribution, however, is still very similar to the prescribed distribution. At angles of attack above 12 deg, the addition of a wing-fuselage strake results in a significant increase in lifting pressure coefficient at all wing stations outboard of the strake-wing intersection.

Florida Governor Jeb Bush joins Daniel Goldin at KSC for STS-97 launch

NASA Technical Reports Server (NTRS)

2000-01-01

Enjoying a light moment before the launch of Space Shuttle Endeavour on mission STS-97 are NASA Administrator Daniel Goldin (left) and Florida Governor Jeb Bush (right). Between them is California Congressman Dana Rohrabacher. Guests of NASA, they viewed the launch from the Banana Creek VIP Site. Liftoff of Endeavour occurred on time at 10:06:01 p.m. EST with a crew of five. The sixth construction flight to the International Space Station, Endeavour is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to provide power to the Space Station. The 11-day mission includes two spacewalks to complete the solar array connections. Endeavour is expected to land Dec. 11 at 6:19 p.m. EST.

A direct method for synthesizing low-order optimal feedback control laws with application to flutter suppression

NASA Technical Reports Server (NTRS)

Mukhopadhyay, V.; Newsom, J. R.; Abel, I.

1980-01-01

A direct method of synthesizing a low-order optimal feedback control law for a high order system is presented. A nonlinear programming algorithm is employed to search for the control law design variables that minimize a performance index defined by a weighted sum of mean square steady state responses and control inputs. The controller is shown to be equivalent to a partial state estimator. The method is applied to the problem of active flutter suppression. Numerical results are presented for a 20th order system representing an aeroelastic wind-tunnel wing model. Low-order controllers (fourth and sixth order) are compared with a full order (20th order) optimal controller and found to provide near optimal performance with adequate stability margins.

Preliminary noise tests of the engine-over-the-wing concept. i: 30 deg - 60 deg flap position

NASA Technical Reports Server (NTRS)

Reshotko, M.; Olsen, W. A.; Dorsch, R. G.

1972-01-01

The results of preliminary acoustic tests of the engine over the wing concept are summarized. The tests were conducted with a small wing section model (32 cm chord) having two flaps set at the landing position, which is 30 and 60 deg respectively. The engine exhaust was simulated by an air jet from a convergent nozzle having a nominal diameter of 5.1 centimeters. Factors investigated for their effect on noise include nozzle location, wing shielding, flap leakage, nozzle shape, exhaust deflectors, and internally generated exhaust noise.

Pressure measurements on a thick cambered and twisted 58 deg delta wing at high subsonic speeds

NASA Technical Reports Server (NTRS)

Chu, Julio; Lamar, John E.

1987-01-01

A pressure experiment at high subsonic speeds was conducted by a cambered and twisted thick delta wing at the design condition (Mach number 0.80), as well as at nearby Mach numbers (0.75 and 0.83) and over an angle-of-attack range. Effects of twin vertical tails on the wing pressure measurements were also assessed. Comparisons of detailed theoretical and experimental surface pressures and sectional characteristics for the wing alone are presented. The theoretical codes employed are FLO-57, FLO-28, PAN AIR, and the Vortex Lattice Method-Suction Analogy.

Deformable wing kinematics in the desert locust: how and why do camber, twist and topography vary through the stroke?

PubMed Central

Walker, Simon M.; Thomas, Adrian L. R.; Taylor, Graham K.

2009-01-01

Here, we present a detailed analysis of the wing kinematics and wing deformations of desert locusts (Schistocerca gregaria, Forskål) flying tethered in a wind tunnel. We filmed them using four high-speed digital video cameras, and used photogrammetry to reconstruct the motion of more than 100 identified points. Whereas the hindwing motions were highly stereotyped, the forewing motions showed considerable variation, consistent with a role in flight control. Both wings were positively cambered on the downstroke. The hindwing was cambered through an ‘umbrella effect’ whereby the trailing edge tension compressed the radial veins during the downstroke. Hindwing camber was reversed on the upstroke as the wing fan corrugated, reducing the projected area by 30 per cent, and releasing the tension in the trailing edge. Both the wings were strongly twisted from the root to the tip. The linear decrease in incidence along the hindwing on the downstroke precisely counteracts the linear increase in the angle of attack that would otherwise occur in root flapping for an untwisted wing. The consequent near-constant angle of attack is reminiscent of the optimum for a propeller of constant aerofoil section, wherein a linear twist distribution allows each section to operate at the unique angle of attack maximizing the lift to drag ratio. This implies tuning of the structural, morphological and kinematic parameters of the hindwing for efficient aerodynamic force production. PMID:19091683

Aerodynamic Characterization of a Thin, High-Performance Airfoil for Use in Ground Fluids Testing

NASA Technical Reports Server (NTRS)

Broeren, Andy P.; Lee, Sam; Clark, Catherine

2013-01-01

The FAA has worked with Transport Canada and others to develop allowance times for aircraft operating in ice-pellet precipitation. Wind-tunnel testing has been carried out to better understand the flowoff characteristics and resulting aerodynamic effects of anti-icing fluids contaminated with ice pellets using a thin, high-performance wing section at the National Research Council of Canada Propulsion and Icing Wind Tunnel. The objective of this paper is to characterize the aerodynamic behavior of this wing section in order to better understand the adverse aerodynamic effects of anti-icing fluids and ice-pellet contamination. Aerodynamic performance data, boundary-layer surveys and flow visualization were conducted at a Reynolds number of approximately 6.0 x 10(exp 6) and a Mach number of 0.12. The clean, baseline model exhibited leading-edge stall characteristics including a leading-edge laminar separation bubble and minimal or no separation on the trailing edge of the main element or flap. These results were consistent with expected 2-D aerodynamics and showed no anomalies that could adversely affect the evaluation of anti-icing fluids and ice-pellet contamination on the wing. Tests conducted with roughness and leading-edge flow disturbances helped to explain the aerodynamic impact of the anti-icing fluids and contamination. The stalling characteristics of the wing section with fluid and contamination appear to be driven at least partially by the effects of a secondary wave of fluid that forms near the leading edge as the wing is rotated in the simulated takeoff profile. These results have provided a much more complete understanding of the adverse aerodynamic effects of anti-icing fluids and ice-pellet contamination on this wing section. This is important since these results are used, in part, to develop the ice-pellet allowance times that are applicable to many different airplanes.

Aerodynamic Characterization of a Thin, High-Performance Airfoil for Use in Ground Fluids Testing

NASA Technical Reports Server (NTRS)

Broeren, Andy P.; Lee, Sam; Clark, Catherine

2013-01-01

The FAA has worked with Transport Canada and others to develop allowance times for aircraft operating in ice-pellet precipitation. Wind-tunnel testing has been carried out to better understand the flowoff characteristics and resulting aerodynamic effects of anti-icing fluids contaminated with ice pellets using a thin, high-performance wing section at the National Research Council of Canada Propulsion and Icing Wind Tunnel. The objective of this paper is to characterize the aerodynamic behavior of this wing section in order to better understand the adverse aerodynamic effects of anti-icing fluids and ice-pellet contamination. Aerodynamic performance data, boundary-layer surveys and flow visualization were conducted at a Reynolds number of approximately 6.0×10(exp 6) and a Mach number of 0.12. The clean, baseline model exhibited leading-edge stall characteristics including a leading-edge laminar separation bubble and minimal or no separation on the trailing edge of the main element or flap. These results were consistent with expected 2-D aerodynamics and showed no anomalies that could adversely affect the evaluation of anti-icing fluids and ice-pellet contamination on the wing. Tests conducted with roughness and leading-edge flow disturbances helped to explain the aerodynamic impact of the anti-icing fluids and contamination. The stalling characteristics of the wing section with fluid and contamination appear to be driven at least partially by the effects of a secondary wave of fluid that forms near the leading edge as the wing is rotated in the simulated takeoff profile. These results have provided a much more complete understanding of the adverse aerodynamic effects of anti-icing fluids and ice-pellet contamination on this wing section. This is important since these results are used, in part, to develop the ice-pellet allowance times that are applicable to many different airplanes.

An Investigation of Four Wings of Square Plan Form at a Mach Number of 6.9 in the Langley 11-inch Hypersonic Tunnel

NASA Technical Reports Server (NTRS)

Mclellan, Charles H; Bertram, Mitchel H; Moore, John A

1957-01-01

The results of pressure-distribution and force tests of four wings at a Mach number of about 6.9 and a Reynolds number of 0.98 x 10(6) in the Langley 11-inch hypersonic tunnel are presented. The wings had a square plan form, a 5-percent-chord maximum thickness, and diamond, half-diamond, wedge, and half-circular sections.

AST Composite Wing Program: Executive Summary

NASA Technical Reports Server (NTRS)

Karal, Michael

2001-01-01

The Boeing Company demonstrated the application of stitched/resin infused (S/RFI) composite materials on commercial transport aircraft primary wing structures under the Advanced Subsonic technology (AST) Composite Wing contract. This report describes a weight trade study utilizing a wing torque box design applicable to a 220-passenger commercial aircraft and was used to verify the weight savings a S/RFI structure would offer compared to an identical aluminum wing box design. This trade study was performed in the AST Composite Wing program, and the overall weight savings are reported. Previous program work involved the design of a S/RFI-base-line wing box structural test component and its associated testing hardware. This detail structural design effort which is known as the "semi-span" in this report, was completed under a previous NASA contract. The full-scale wing design was based on a configuration for a MD-90-40X airplane, and the objective of this structural test component was to demonstrate the maturity of the S/RFI technology through the evaluation of a full-scale wing box/fuselage section structural test. However, scope reductions of the AST Composite Wing Program pre-vented the fabrication and evaluation of this wing box structure. Results obtained from the weight trade study, the full-scale test component design effort, fabrication, design development testing, and full-scale testing of the semi-span wing box are reported.

Fracture temperature and flaw growth in nitronic 40 at cryogenic temperatures

NASA Technical Reports Server (NTRS)

Domack, M. S.

1984-01-01

The fracture resistance and fatigue response of Armco Nitronic 40 austenitic stainless steel were evaluated under cryogenic conditions. Tensile, fracture toughness and fatigue crack growth properties were measured at -275 F. The tensile yield strength was approximately 120 ksi and the fracture toughness was estimated to be 350 ksi-in /2 on the basis of fracture toughness measurements. Testing was conducted to evaluate the behavior of a simulated section of the wing of the Pathfinder 1 model subject to a load and temperature history typical of that for testing in the National Transonic Facility. The wing section model incorporated a proposed brazing technique for pressure-transducer attachment. The simulated wing section performed satisfactorily at stress levels of nearly 60 percent of the material yield strength. The brazing technique proved to be an effective method of transducer attachment under conditions of high stress levels and large temperature excursions.

A model for nocturnal frost formation on a wing section: Aircraft takeoff performance penalties

NASA Technical Reports Server (NTRS)

Dietenberger, M. A.

1983-01-01

The nocturnal frost formation on a wing section, to explain the hazard associated with frost during takeoff was investigated. A model of nocturnal frost formation on a wing section which predicts when the nocturnal frost will form and also its thickness and density as a function of time was developed. The aerodynamic penalities as related to the nocturnal frost formation properties were analyzed to determine how much the takeoff performance would be degraded by a specific frost layer. With an aircraft takeoff assuming equations representing a steady climbing flight, it is determined that a reduction in the maximum gross weight or a partial frost clearance and a reduction in the takeoff angle of attack is needed to neutralize drag and life penalities which are due to frost. Atmospheric conditions which produce the most hazardous frost buildup are determined.

Wave drag as the objective function in transonic fighter wing optimization

NASA Technical Reports Server (NTRS)

Phillips, P. S.

1984-01-01

The original computational method for determining wave drag in a three dimensional transonic analysis method was replaced by a wave drag formula based on the loss in momentum across an isentropic shock. This formula was used as the objective function in a numerical optimization procedure to reduce the wave drag of a fighter wing at transonic maneuver conditions. The optimization procedure minimized wave drag through modifications to the wing section contours defined by a wing profile shape function. A significant reduction in wave drag was achieved while maintaining a high lift coefficient. Comparisons of the pressure distributions for the initial and optimized wing geometries showed significant reductions in the leading-edge peaks and shock strength across the span.

A unified viscous theory of lift and drag of 2-D thin airfoils and 3-D thin wings

NASA Technical Reports Server (NTRS)

Yates, John E.

1991-01-01

A unified viscous theory of 2-D thin airfoils and 3-D thin wings is developed with numerical examples. The viscous theory of the load distribution is unique and tends to the classical inviscid result with Kutta condition in the high Reynolds number limit. A new theory of 2-D section induced drag is introduced with specific applications to three cases of interest: (1) constant angle of attack; (2) parabolic camber; and (3) a flapped airfoil. The first case is also extended to a profiled leading edge foil. The well-known drag due to absence of leading edge suction is derived from the viscous theory. It is independent of Reynolds number for zero thickness and varies inversely with the square root of the Reynolds number based on the leading edge radius for profiled sections. The role of turbulence in the section induced drag problem is discussed. A theory of minimum section induced drag is derived and applied. For low Reynolds number the minimum drag load tends to the constant angle of attack solution and for high Reynolds number to an approximation of the parabolic camber solution. The parabolic camber section induced drag is about 4 percent greater than the ideal minimum at high Reynolds number. Two new concepts, the viscous induced drag angle and the viscous induced separation potential are introduced. The separation potential is calculated for three 2-D cases and for a 3-D rectangular wing. The potential is calculated with input from a standard doublet lattice wing code without recourse to any boundary layer calculations. Separation is indicated in regions where it is observed experimentally. The classical induced drag is recovered in the 3-D high Reynolds number limit with an additional contribution that is Reynold number dependent. The 3-D viscous theory of minimum induced drag yields an equation for the optimal spanwise and chordwise load distribution. The design of optimal wing tip planforms and camber distributions is possible with the viscous 3-D wing theory.

Preliminary wing model tests in the variable density wind tunnel of the National Advisory Committee for Aeronautics

NASA Technical Reports Server (NTRS)

Munk, Max M

1926-01-01

This report contains the results of a series of tests with three wing models. By changing the section of one of the models and painting the surface of another, the number of models tested was increased to five. The tests were made in order to obtain some general information on the air forces on wing sections at a high Reynolds number and in particular to make sure that the Reynolds number is really the important factor, and not other things like the roughness of the surface and the sharpness of the trailing edge. The few tests described in this report seem to indicate that the air forces at a high Reynolds number are not equivalent to respective air forces at a low Reynolds number (as in an ordinary atmospheric wind tunnel). The drag appears smaller at a high Reynolds number and the maximum lift is increased in some cases. The roughness of the surface and the sharpness of the trailing edge do not materially change the results, so that we feel confident that tests with systematic series of different wing sections will bring consistent results, important and highly useful to the designer.

A mathematical model for the thrust force generated by a flapping elastic wing

NASA Astrophysics Data System (ADS)

Tarasov, Alexander E.; Sumbatyan, Mezhlum A.

2012-11-01

The physical nature of the thrust force generated by flapping wings is of a long-time interest of many researchers. The idea of the thrust effect came from the observation of birds' flight. Apparently, Leonardo da Vinci was first who tried to explain the mechanism of the flapping wing trust, for possible engineering applications. Nevertheless, the fundamental basics of a theoretical study of wing oscillations were laid only near the beginning of the 20th century. The thrust effect of the flapping wing was explained by Knoller in 1909 and Betz in 1912, independently. The principal problem in this theory is to define an optimal deformation law which provides the flapping wing to work with highest efficiency. In the present paper we study a rectangular elastic wing of finite span as a propulsion device. We propose an analytical approach, to study harmonic oscillations of a thin elastic rectangular wing at zero attack angle in a flow of inviscid incompressible fluid. The problem is reduced to an integro-differential equation, in frames of the "plane sections" hypothesis.

Aerodynamic characteristics of wings designed with a combined-theory method to cruise at a Mach number of 4.5

NASA Technical Reports Server (NTRS)

Mack, Robert J.

1988-01-01

A wind-tunnel study was conducted to determine the capability of a method combining linear theory and shock-expansion theory to design optimum camber surfaces for wings that will fly at high-supersonic/low-hypersonic speeds. Three force models (a flat-plate reference wing and two cambered and twisted wings) were used to obtain aerodynamic lift, drag, and pitching-moment data. A fourth pressure-orifice model was used to obtain surface-pressure data. All four wing models had the same planform, airfoil section, and centerbody area distribution. The design Mach number was 4.5, but data were also obtained at Mach numbers of 3.5 and 4.0. Results of these tests indicated that the use of airfoil thickness as a theoretical optimum, camber-surface design constraint did not improve the aerodynamic efficiency or performance of a wing as compared with a wing that was designed with a zero-thickness airfoil (linear-theory) constraint.

SpaRibs Geometry Parameterization for Wings with Multiple Sections using Single Design

NASA Technical Reports Server (NTRS)

De, Shuvodeep; Jrad, Mohamed; Locatelli, Davide; Kapania, Rakesh K.; Baker, Myles; Pak, Chan-Gi

2017-01-01

The SpaRibs topology of an aircraft wing has a significant effect on its structural behavior and stability as well as the flutter performance. The development of additive manufacturing techniques like Electron Beam Free Form Fabrication (EBF3) has made it feasible to manufacture aircraft wings with curvilinear spars, ribs (SpaRibs) and stiffeners. In this article a new global-local optimization framework for wing with multiple sections using curvilinear SpaRibs is described. A single design space is used to parameterize the SpaRibs geometry. This method has been implemented using MSC-PATRAN to create a broad range of SpaRibs topologies using limited number of parameters. It ensures C0 and C1 continuities in SpaRibs geometry at the junction of two wing sections with airfoil thickness gradient discontinuity as well as mesh continuity between all structural components. This method is advantageous in complex multi-disciplinary optimization due to its potential to reduce the number of design variables. For the global-local optimization the local panels are generated by an algorithm which is totally based on a set algebra on the connectivity matrix data. The great advantage of this method is that it is completely independent of the coordinates of the nodes of the finite element model. It is also independent of the order in which the elements are distributed in the FEM. The code is verified by optimizing of the CRM Baseline model at trim condition at Mach number equal to 0.85 for five different angle of attack (-2deg, 0deg,2deg,4deg and 6deg). The final weight of the wing is 19,090.61 lb. This value is comparable to that obtained by Qiang et al. 6 (19,269 lb).

The Strength of One-Piece Solid, Build-Up and Laminated Wood Airplane Wing Beams

NASA Technical Reports Server (NTRS)

Nelson, John H

1920-01-01

The purpose of this report is to summarize the results of all wood airplane wing beams tested to date in the Bureau of Standards Laboratory in order that the various kinds of wood and methods of construction may be compared. All beams tested were of an I section and the majority were somewhat similar in size and cross section to the front wing beam of the Curtiss JN-4 machine. Construction methods may be classed as (1) solid beams cut from solid stock; (2) three-piece beams, built up of three pieces, web and flanges glued together by a tongue-and-groove joint and (3) laminated beams built up of thin laminations of wood glued together.

Flight in slow motion: aerodynamics of the pterosaur wing.

PubMed

Palmer, Colin

2011-06-22

The flight of pterosaurs and the extreme sizes of some taxa have long perplexed evolutionary biologists. Past reconstructions of flight capability were handicapped by the available aerodynamic data, which was unrepresentative of possible pterosaur wing profiles. I report wind tunnel tests on a range of possible pterosaur wing sections and quantify the likely performance for the first time. These sections have substantially higher profile drag and maximum lift coefficients than those assumed before, suggesting that large pterosaurs were aerodynamically less efficient and could fly more slowly than previously estimated. In order to achieve higher efficiency, the wing bones must be faired, which implies extensive regions of pneumatized tissue. Whether faired or not, the pterosaur wings were adapted to low-speed flight, unsuited to marine style dynamic soaring but adapted for thermal/slope soaring and controlled, low-speed landing. Because their thin-walled bones were susceptible to impact damage, slow flight would have helped to avoid injury and may have contributed to their attaining much larger sizes than fossil or extant birds. The trade-off would have been an extreme vulnerability to strong or turbulent winds both in flight and on the ground, akin to modern-day paragliders.

Low-speed wind tunnel investigation of a semispan STOL jet transport wing body with an upper surface blown jet flap

NASA Technical Reports Server (NTRS)

Phelps, A. E., III; Letko, W.; Henderson, R. L.

1973-01-01

An investigation of the static longitudinal aerodynamic characteristics of a semispan STOL jet transport wing-body with an upper-surface blown jet flap for lift augmentation was conducted in a low-speed wind tunnel having a 12-ft octagonal test section. The semispan swept wing had an aspect ratio of 3.92 (7.84 for the full span) and had two simulated turbofan engines mounted ahead of and above the wing in a siamese pod equipped with an exhaust deflector. The purpose of the deflector was to spread the engine exhaust into a jet sheet attached to the upper surface of the wing so that it would turn downward over the flap and provide lift augmentation. The wing also had optional boundary-layer control provided by air blowing through a thin slot over a full-span plain trailing-edge flap.

Pressure Distribution Over a Thick, Tapered and Twisted Monoplane Wing Model-NACA 81-J

NASA Technical Reports Server (NTRS)

Wenzinger, Carl J

1932-01-01

This reports presents the results of pressure distribution tests on a thick, tapered and twisted monoplane wing model. The investigation was conducted for the purpose of obtaining data on the aerodynamic characteristics of the new wing and to provide additional information suitable for use in the design of tapered cantilever wings. The tests included angles of attack up to 90 degrees. The span loading over the wing was approximately of elliptical shape, which gave rise to relatively small bending moments about the root. The angle of zero lift for all sections along the span varied only within plus or minus 0.4 degree of the angle of zero lift for the whole wing, resulting in small leading edge loads for the high-speed condition of flight. The results also add to the available information for the study of large angles of attack.

Tests of Nacelle-Propeller Combinations in Various Positions with Reference to Wings III : Clark Y Wing - Various Radial-engine Cowlings - Tractor Propeller

NASA Technical Reports Server (NTRS)

Wood, Donald H

1933-01-01

This report is the third of a series giving the results obtained in the 20-foot wind tunnel on the interference drag, and propulsive efficiency of nacelle-propeller-wing combinations. The first report gave the results of the tests of an NACA cowled air-cooled engine nacelle with tractor propeller located in 21 positions with reference to a thick wing. The second report gave the results for several engine cowlings and nacelles with tractor propeller located in four positions with reference to same wing. The present report gives results of tests of the same nacelles and cowlings in the same positions with reference to a smaller wing of Clark y section. The lift, drag, and propulsive efficiency were determined at several angles of attack for each cowling and in each nacelle location.

The effects of leading edge modifications on the post-stall characteristics of wings

NASA Technical Reports Server (NTRS)

Winkelmann, A. E.; Barlow, J. B.; Saini, J. K.; Anderson, J. D., Jr.; Jones, E.

1980-01-01

An investigation of the effects of leading edge modifications on the post-stall characteristics of two rectangular planform wings in a series of low speed wind tunnel tests is presented. Abrupt discontinuities in the leading edge shape of the wings were produced by placing a nose glove over a portion of the span or by deflecting sections of a segmented leading edge flap. Six component balance data, oil flow visualization photographs, and pressure distribution measurements were obtained, and tests made to study the development of flow separation at stall on small scale planform wing models. Results of oil flow visualization tests at and beyond stall showed the formation of counter-rotating swirl patterns on the upper surface of the '2-D' and '3-D' wings, and results of a numerical lifting line technique applied to wings with leading edge modifications are included.

The oscillating wing with aerodynamically balanced elevator

NASA Technical Reports Server (NTRS)

Kussner, H G; Schwartz, I

1941-01-01

The two-dimensional problem of the oscillating wing with aerodynamically balanced elevator is treated in the manner that the wing is replaced by a plate with bends and stages and the airfoil section by a mean line consisting of one or more straights. The computed formulas and tables permit, on these premises, the prediction of the pressure distribution and of the aerodynamic reactions of oscillating elevators and tabs with any position of elevator hinge in respect to elevator leading edge.

Velocity distributions on two-dimensional wing-duct inlets by conformal mapping

NASA Technical Reports Server (NTRS)

Perl, W; Moses, H E

1948-01-01

The conformal-mapping method of the Cartesian mapping function is applied to the determination of the velocity distribution on arbitrary two-dimensional duct-inlet shapes such as are used in wing installations. An idealized form of the actual wing-duct inlet is analyzed. The effects of leading edge stagger, inlet-velocity ratio, and section lift coefficients on the velocity distribution are included in the analysis. Numerical examples are given and, in part, compared with experimental data.

An experimental investigation of vortex breakdown on a delta wing

NASA Technical Reports Server (NTRS)

Payne, F. M.; Nelson, R. C.

1986-01-01

An experimental investigation of vortex breakdown on delta wings at high angles is presented. Thin delta wings having sweep angles of 70, 75, 80 and 85 degrees are being studied. Smoke flow visualization and the laser light sheet technique are being used to obtain cross-sectional views of the leading edge vortices as they break down. At low tunnel speeds (as low as 3 m/s) details of the flow, which are usually imperceptible or blurred at higher speeds, can be clearly seen. A combination of lateral and longitudinal cross-sectional views provides information on the three dimensional nature of the vortex structure before, during and after breakdown. Whereas details of the flow are identified in still photographs, the dynamic characteristics of the breakdown process were recorded using high speed movies. Velocity measurements were obtained using a laser Doppler anemometer with the 70 degree delta wing at 30 degrees angle of attack. The measurements show that when breakdown occurs the core flow transforms from a jet-like flow to a wake-like flow.

Proceedings of the Sixth General Meeting of the International VLBI Service for Geodesy and Astrometry

NASA Technical Reports Server (NTRS)

Behrend, Dirk (Editor); Baver, Karen D. (Editor)

2010-01-01

This volume is the proceedings of the sixth General Meeting of the International VLBI Service for Geodesy and Astrometry (IVS), held in Hobart, Tasmania, Australia, February 7-13, 2010. The contents of this volume also appear on the IVS Web site at http://ivscc.gsfc.nasa.gov/publications/gm2010. The keynote of the sixth GM was the new perspectives of the next generation VLBI system under the theme "VLBI2010: From Vision to Reality". The goal of the meeting was to provide an interesting and informative program for a wide cross-section of IVS members, including station operators, program managers, and analysts. This volume contains 88 papers. All papers were edited by the editors for usage of the English language, form, and minor content-related issues.

Structural Test Documentation and Results for the McDonnell Douglas All-Composite Wing Stub Box

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.; Bush, Harold G.

1997-01-01

The results of a series of tests conducted at the NASA Langley Research Center to evaluate the behavior of an all-composite full-scale wing box are presented. The wing stub box is representative of a section of a commercial transport aircraft wing box and was designed and constructed by McDonnell Douglas Aerospace Company as part of the NASA Advanced Composites Technology (ACT) program. Tests were conducted with and without low-speed impact damage and repairs. The structure with nonvisible impact damage carried 140 percent of Design Limit Load prior to failure through an impact site.

The experimental and calculated characteristics of 22 tapered wings

NASA Technical Reports Server (NTRS)

Anderson, Raymond F

1938-01-01

The experimental and calculated aerodynamic characteristics of 22 tapered wings are compared, using tests made in the variable-density wind tunnel. The wings had aspect ratios from 6 to 12 and taper ratios from 1:6:1 and 5:1. The compared characteristics are the pitching moment, the aerodynamic-center position, the lift-curve slope, the maximum lift coefficient, and the curves of drag. The method of obtaining the calculated values is based on the use of wing theory and experimentally determined airfoil section data. In general, the experimental and calculated characteristics are in sufficiently good agreement that the method may be applied to many problems of airplane design.

Investigation of Downwash, Sidewash, and Mach Number Distribution Behind a Rectangular Wing at a Mach Number of 2.41

NASA Technical Reports Server (NTRS)

Adamson, David; Boatright, William B

1957-01-01

An investigation of the nature of the flow field behind a rectangular wing of circular arc cross section has been conducted in the Langley 9-inch supersonic tunnel. Pitot- and static-pressure surveys covering a region of flow behind the wing have been made together with detailed pitot surveys throughout the region of the wake. In addition, the flow direction has been measured by means of a weathercocking vane. Theoretical calculations have been made to obtain the variation of both downwash and sidewash with angle of attack by using the superposition method of Lagerstrom, Graham, and Grosslight. In addition, the effect of wing thickness on the sidewash with the wing at 0 degree angle of attack has been evaluated.

Slot Nozzle Effects for Reduced Sonic Boom on a Generic Supersonic Wing Section

NASA Technical Reports Server (NTRS)

Caster, Raymond S.

2010-01-01

NASA has conducted research programs to reduce or eliminate the operational restrictions of supersonic aircraft over populated areas. Restrictions are due to the disturbance from the sonic boom, caused by the coalescence of shock waves formed off the aircraft. Results from two-dimensional computational fluid dynamic (CFD) analyses (performed on a baseline Mach 2.0 nozzle in a simulated Mach 2.2 flow) indicate that over-expanded and under-expanded operation of the nozzle has an effect on the N-wave boom signature. Analyses demonstrate the feasibility of reducing the magnitude of the sonic boom N-wave by controlling the nozzle plume interaction with the nozzle boat tail shock structure. This work was extended to study the impact of integrating a high aspect ratio exhaust nozzle or long slot nozzle on the trailing edge of a supersonic wing. The nozzle is operated in a highly under-expanded condition, creating a large exhaust plume and a shock at the trailing edge of the wing. This shock interacts with and suppresses the expansion wave caused by the wing, a major contributor to the sonic boom signature. The goal was to reduce the near field pressures caused by the expansion using a slot nozzle located at the wing trailing edge. Results from CFD analysis on a simulated wing cross-section and a slot nozzle indicate potential reductions in sonic boom signature compared to a baseline wing with no propulsion or trailing edge exhaust. Future studies could investigate if this effect could be useful on a supersonic aircraft for main propulsion, auxiliary propulsion, or flow control.

A wind-tunnel investigation at high subsonic speeds of the lateral control characteristics of various plain spoiler configurations on a 3-percent-thick 60 degree delta wing

NASA Technical Reports Server (NTRS)

Wiley, Harleth G

1954-01-01

Results are presented of wind-tunnel investigations at Mach numbers of 0.60 to 0.94 and angles of attack of -2 degrees to about 24 degrees to determine the lateral control characteristics of spoilers with various wing chord-wise and spanwise locations and spoiler spans and deflections on thin 60 degree delta wing of NACA 65a003 airfoil section parallel to free stream.

Some effects of wing and body geometry on the aerodynamic characteristics of configurations designed for high supersonic Mach numbers

NASA Technical Reports Server (NTRS)

Spearman, M. L.; Tice, David C.; Braswell, Dorothy O.

1992-01-01

Experimental and theoretical results are presented for a family of aerodynamic configurations for flight Mach numbers as high as Mach 8. All of these generic configurations involved 70-deg sweep delta planform wings of three different areas and three fuselage shapes with circular-to-elliptical cross sections. It is noted that fuselage ellipticity enhances lift-curve slope and maximum L/D, while decreasing static longitudinal stability (especially with smaller wing areas).

Pathfinder aircraft in flight

NASA Image and Video Library

1995-07-27

The Pathfinder research aircraft's wing structure was clearly defined as it soared under a clear blue sky during a test flight July 27, 1995, from Dryden Flight Research Center, Edwards, California. The center section and outer wing panels of the aircraft had ribs constructed of thin plastic foam, while the ribs in the inner wing panels are fabricated from lightweight composite material. Developed by AeroVironment, Inc., the Pathfinder was one of several unmanned aircraft being evaluated under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program.

Method for calculating the rolling and yawing moments due to rolling for unswept wings with or without flaps or ailerons by use of nonlinear section lift data

NASA Technical Reports Server (NTRS)

Martina, Albert P

1953-01-01

The methods of NACA Reports 865 and 1090 have been applied to the calculation of the rolling- and yawing-moment coefficients due to rolling for unswept wings with or without flaps or ailerons. The methods allow the use of nonlinear section lift data together with lifting-line theory. Two calculated examples are presented in simplified computing forms in order to illustrate the procedures involved.

Nonlinear Analysis and Preliminary Testing Results of a Hybrid Wing Body Center Section Test Article

NASA Technical Reports Server (NTRS)

Przekop, Adam; Jegley, Dawn C.; Rouse, Marshall; Lovejoy, Andrew E.; Wu, Hsi-Yung T.

2015-01-01

A large test article was recently designed, analyzed, fabricated, and successfully tested up to the representative design ultimate loads to demonstrate that stiffened composite panels with through-the-thickness reinforcement are a viable option for the next generation large transport category aircraft, including non-conventional configurations such as the hybrid wing body. This paper focuses on finite element analysis and test data correlation of the hybrid wing body center section test article under mechanical, pressure and combined load conditions. Good agreement between predictive nonlinear finite element analysis and test data is found. Results indicate that a geometrically nonlinear analysis is needed to accurately capture the behavior of the non-circular pressurized and highly-stressed structure when the design approach permits local buckling.

Application of a Third Order Upwind Scheme to Viscous Flow over Clean and Iced Wings

NASA Technical Reports Server (NTRS)

Bangalore, A.; Phaengsook, N.; Sankar, L. N.

1994-01-01

A 3-D compressible Navier-Stokes solver has been developed and applied to 3-D viscous flow over clean and iced wings. This method uses a third order accurate finite volume scheme with flux difference splitting to model the inviscid fluxes, and second order accurate symmetric differences to model the viscous terms. The effects of turbulence are modeled using a Kappa-epsilon model. In the vicinity of the sold walls the kappa and epsilon values are modeled using Gorski's algebraic model. Sampling results are presented for surface pressure distributions, for untapered swept clean and iced wings made of NACA 0012 airfoil sections. The leading edge of these sections is modified using a simulated ice shape. Comparisons with experimental data are given.

A method for the design of transonic flexible wings

NASA Technical Reports Server (NTRS)

Smith, Leigh Ann; Campbell, Richard L.

1990-01-01

Methodology was developed for designing airfoils and wings at transonic speeds which includes a technique that can account for static aeroelastic deflections. This procedure is capable of designing either supercritical or more conventional airfoil sections. Methods for including viscous effects are also illustrated and are shown to give accurate results. The methodology developed is an interactive system containing three major parts. A design module was developed which modifies airfoil sections to achieve a desired pressure distribution. This design module works in conjunction with an aerodynamic analysis module, which for this study is a small perturbation transonic flow code. Additionally, an aeroelastic module is included which determines the wing deformation due to the calculated aerodynamic loads. Because of the modular nature of the method, it can be easily coupled with any aerodynamic analysis code.

Longitudinal Stability and Drag Characteristics at Mach Numbers from 0.70 to 1.37 of Rocket-propelled Models Having a Modified Triangular Wing

NASA Technical Reports Server (NTRS)

Chapman, Rowe, Jr; Morrow, John D

1952-01-01

A modified triangular wing of aspect ratio 2.53 having an airfoil section 3.7 percent thick at the root and 5.98 percent thick at the tip was designed in an attempt to improve the lift and drag characteristics of triangular wings. Free-flight drag and stability tests were made using rocket-propelled models equipped with the modified wing. The Mach number range of the test was from 0.70 to 1.37. Test results indicated the following: The lift-curve slope of wing plus fuselage approaches the theoretical value of wing alone at supersonic Mach numbers. The drag coefficient, based on total wing area, for wing plus interference was approximately 0.0035 at subsonic Mach numbers and 0.0080 at supersonic Mach numbers. The maximum shift in aerodynamic center for the complete configuration was 14 percent in the rearward direction from the forward position of 51.5 percent of mean aerodynamic chord at subsonic Mach numbers. The variation of lift and moment with angle of attack was linear at supersonic Mach numbers for the range of coefficients covered in the test. The high value of lift-curve slope was considered to be a significant result attributable to the wing modifications.

Preliminary Weight Savings Estimate for a Commercial Transport Wing Using Rod-Stiffened Stitched Composite Technology

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.

2015-01-01

A structural concept called pultruded rod stitched efficient unitized structure (PRSEUS) was developed by the Boeing Company to address the complex structural design aspects associated with a pressurized hybrid wing body (HWB) aircraft configuration. While PRSEUS was an enabling technology for the pressurized HWB structure, limited investigation of PRSEUS for other aircraft structures, such as circular fuselages and wings, has been done. Therefore, a study was undertaken to investigate the potential weight savings afforded by using the PRSEUS concept for a commercial transport wing. The study applied PRSEUS to the Advanced Subsonic Technology (AST) Program composite semi-span test article, which was sized using three load cases. The initial PRSEUS design was developed by matching cross-sectional stiffnesses for each stringer/skin combination within the wing covers, then the design was modified to ensure that the PRSEUS design satisfied the design criteria. It was found that the PRSEUS wing design exhibited weight savings over the blade-stiffened composite AST Program wing of nearly 9%, and a weight savings of 49% and 29% for the lower and upper covers, respectively, compared to an equivalent metallic wing.

Transonic Aerodynamic Loading Characteristics of a Wing-Body-Tail Combination Having a 52.5 deg. Sweptback Wing of Aspect Ratio 3 With Conical Wing Camber and Body Indentation for a Design Mach Number of Square Root of 2

NASA Technical Reports Server (NTRS)

Cassetti, Marlowe D.; Re, Richard J.; Igoe, William B.

1961-01-01

An investigation has been made of the effects of conical wing camber and body indentation according to the supersonic area rule on the aerodynamic wing loading characteristics of a wing-body-tail configuration at transonic speeds. The wing aspect ratio was 3, taper ratio was 0.1, and quarter-chord-line sweepback was 52.5 deg. with 3-percent-thick airfoil sections. The tests were conducted in the Langley 16-foot transonic tunnel at Mach numbers from 0.80 to 1.05 and at angles of attack from 0 deg. to 14 deg., with Reynolds numbers based on mean aerodynamic chord varying from 7 x 10(exp 6) to 8 x 10(exp 6). Conical camber delayed wing-tip stall and reduced the severity of the accompanying longitudinal instability but did not appreciably affect the spanwise load distribution at angles of attack below tip stall. Body indentation reduced the transonic chordwise center-of-pressure travel from about 8 percent to 5 percent of the mean aerodynamic chord.

Icing flight research: Aerodynamic effects of ice and ice shape documentation with stereo photography

NASA Technical Reports Server (NTRS)

Mikkelsen, K. L.; Mcknight, R. C.; Ranaudo, R. J.; Perkins, P. J., Jr.

1985-01-01

Aircraft icing flight research was performed in natural icing conditions. A data base consisting of icing cloud measurements, ice shapes, and aerodynamic measurements is being developed. During research icing encounters the icing cloud was continuously measured. After the encounter, the ice accretion shapes on the wing were documented with a stereo camera system. The increase in wing section drag was measured with a wake survey probe. The overall aircraft performance loss in terms of lift and drag coefficient changes was obtained by steady level speed/power measurements. Selective deicing of the airframe components was performed to determine their contributions to the total drag increase. Engine out capability in terms of power available was analyzed for the iced aircraft. It was shown that the stereo photography system can be used to document ice shapes in flight and that the wake survey probe can measure increases in wing section drag caused by ice. On one flight, the wing section drag coefficient (c sub d) increased approximately 120 percent over the uniced baseline at an aircraft angle of attack of 6 deg. On another flight, the aircraft darg coefficient (c sub d) increased by 75 percent over the uniced baseline at an aircraft lift coefficient (C sub d) of 0.5.

Icing flight research - Aerodynamic effects of ice and ice shape documentation with stereo photography

NASA Technical Reports Server (NTRS)

Mikkelsen, K. L.; Mcknight, R. C.; Ranaudo, R. J.; Perkins, P. J., Jr.

1985-01-01

Aircraft icing flight research was performed in natural icing conditions. A data base consisting of icing cloud measurements, ice shapes, and aerodynamic measurements is being developed. During research icing encounters the icing cloud was continuously measured. After the encounter, the ice accretion shapes on the wing were documented with a stereo camera system. The increase in wing section drag was measured with a wake survey probe. The overall aircraft performance loss in terms of lift and drag coefficient changes were obtained by steady level speed/power measurements. Selective deicing of the airframe components was performed to determine their contributions to the total drag increase. Engine out capability in terms of power available was analyzed for the iced aircraft. It was shown that the stereo photography system can be used to document ice shapes in flight and that the wake survey probe can measure increases in wing section drag caused by ice. On one flight, the wing section drag coefficient (c sub d) increased approximately 120 percent over the uniced baseline at an aircraft angle of attack of 6 deg. On another flight, the aircraft drag coefficient (c sub d) increased by 75 percent over the uniced baseline at an aircraft lift coefficient (c sub d) of 0.5.

Wing-section optimization for supersonic viscous flow

NASA Technical Reports Server (NTRS)

Item, Cem C.; Baysal, Oktay (Editor)

1995-01-01

To improve the shape of a supersonic wing, an automated method that also includes higher fidelity to the flow physics is desirable. With this impetus, an aerodynamic optimization methodology incorporating thin-layer Navier-Stokes equations and sensitivity analysis had been previously developed. Prior to embarking upon the wind design task, the present investigation concentrated on testing the feasibility of the methodology, and the identification of adequate problem formulations, by defining two-dimensional, cost-effective test cases. Starting with two distinctly different initial airfoils, two independent shape optimizations resulted in shapes with similar features: slightly cambered, parabolic profiles with sharp leading- and trailing-edges. Secondly, the normal section to the subsonic portion of the leading edge, which had a high normal angle-of-attack, was considered. The optimization resulted in a shape with twist and camber which eliminated the adverse pressure gradient, hence, exploiting the leading-edge thrust. The wing section shapes obtained in all the test cases had the features predicted by previous studies. Therefore, it was concluded that the flowfield analyses and sensitivity coefficients were computed and fed to the present gradient-based optimizer correctly. Also, as a result of the present two-dimensional study, suggestions were made for the problem formulations which should contribute to an effective wing shape optimization.

Hypersonic shock wave interaction and impingement

NASA Technical Reports Server (NTRS)

Kessler, W. C.; Reilly, J. F.; Sampatacos, E.

1971-01-01

An experimental investigation was conducted on space shuttle type, body-wing configurations. The purpose of the investigation was to determine the effects of body and wing geometry on the hypersonic shock structure about these vehicles and on the resulting surface impingement of interior flow field shock and expansion waves. Schlieren photographs and thermographic phosphor paint data were obtained on three body cross sections with three wing planforms at 40, 50 and 60 degree angles of attack. Specific configuration data were obtained at 0 and 30 degree angles of attack to develop trends. These data were obtained at a nominal Mach number of 13.5 and a freestream unit Reynolds number of 0.7 million per foot. For comparison with these straight wing configurations, data were also obtained on a model of a point design, high cross-range, delta wing orbiter at 40, 50 and 60 degree angles of attack. As expected, the data on this delta wing orbiter indicated that the shock intersection/impingement phenomena associated with straight wing vehicles are considerably more complex than, and result in both windward and leeward surface heating regions not present on, the delta configuration.

The morphological characterization of the forewing of the Manduca sexta species for the application of biomimetic flapping wing micro air vehicles.

PubMed

O'Hara, R P; Palazotto, A N

2012-12-01

To properly model the structural dynamics of the forewing of the Manduca sexta species, it is critical that the material and structural properties of the biological specimen be understood. This paper presents the results of a morphological study that has been conducted to identify the material and structural properties of a sample of male and female Manduca sexta specimens. The average mass, area, shape, size and camber of the wing were evaluated using novel measurement techniques. Further emphasis is placed on studying the critical substructures of the wing: venation and membrane. The venation cross section is measured using detailed pathological techniques over the entire venation of the wing. The elastic modulus of the leading edge veins is experimentally determined using advanced non-contact structural dynamic techniques. The membrane elastic modulus is randomly sampled over the entire wing to determine global material properties for the membrane using nanoindentation. The data gathered from this morphological study form the basis for the replication of future finite element structural models and engineered biomimetic wings for use with flapping wing micro air vehicles.

Electron beam welding of aircraft structures. [joining of titanium alloy wing structures on F-14 aircraft

NASA Technical Reports Server (NTRS)

Witt, R. H.

1972-01-01

Requirements for advanced aircraft have led to more extensive use of titanium alloys and the resultant search for joining processes which can produce lightweight, high strength airframe structures efficiently. As a result, electron beam welding has been investigated. The following F-14A components are now being EB welded in production and are mainly annealed Ti-6Al-4V except for the upper wing cover which is annealed Ti-6Al-6V-2Sn: F-14A wing center section box, and F-14A lower and upper wing covers joined to wing pivot fitting assemblies. Criteria for selection of welding processes, the EB welding facility, development work on EB welding titanium alloys, and F-14A production and sliding seal electron beam welding are reported.

Application of the CAP-TSD unsteady transonic small disturbance program to wing flutter. [Computational Aeroelasticity Program

NASA Technical Reports Server (NTRS)

Bennett, Robert M.; Batina, John T.

1989-01-01

The application and assessment of a computer program called CAP-TSD (Computational Aeroelasticity Program - Transonic Small Disturbance) for flutter predictions are described. Flutter calculations are presented for two thin swept-and-tapered wing planforms with well-defined modal properties. One planform is a series of 45-degree swept wings and the other planform is a clipped delta wing. Comparisons are made between the results of CAP-TSD using the linear equation and no airfoil thickness and the results obtained from a subsonic kernel function analysis. The calculations cover a Mach number range from low subsonic to low supersonic values, including the transonic range, and are compared with subsonic linear theory and experimental data. It is noted that since both wings have very thin airfoil sections, the effects of thickness are minimal.

Effect of canard vertical location, size, and deflection on canard-wing interference at subsonic speeds

NASA Technical Reports Server (NTRS)

Gloss, B. B.; Ray, E. J.; Washburn, K. E.

1978-01-01

A generalized close-coupled canard-wing configuration was tested in a high speed 7 by 10 foot tunnel at Mach numbers of 0.40, 0.70, and 0.85 over an angle-of-attack range from -4 deg to 24 deg. Studies were made to determine the effects of canard vertical location, size, and deflection and wing leading-edge sweep on the longitudinal characteristics of the basic configuration. The two wings tested had thin symmetrical circular-arc airfoil sections with characteristically sharp leading edges swept at 60 deg and 44 deg. Two balances which allow separation of the canard-forebody contribution from the total forces and moments were used in this study.

A special method for finding body distortions that reduce the wave drag of wing and body combinations at supersonic speeds

NASA Technical Reports Server (NTRS)

Lomax, Harvard; Heaslet, Max A

1956-01-01

For a given wing and supersonic Mach number, the problem of shaping an adjoining fuselage so that the combination will have a low wave drag is considered. Only fuselages that can be simulated by singularities (multipoles) distributed along the body axis are studied. However, the optimum variations of such singularities are completely specified in terms of the given wing geometry. An application is made to an elliptic wing having a biconvex section, a thickness-chord ratio equal to 0.05 at the root, and an aspect ratio equal to 3. A comparison of the theoretical results with a wind-tunnel experiment is also presented.

Wind-Tunnel Measurements of Effect of Dive-Recovery Flaps at Transonic Speeds on Models of a Seaplane and a Transport

NASA Technical Reports Server (NTRS)

Heath, Atwood R., Jr.; Ward, Robert J.

1959-01-01

The effects of wing-lower-surface dive-recovery flaps on the aero- dynamic characteristics of a transonic seaplane model and a transonic transport model having 40 deg swept wings have been investigated in the Langley 16-foot transonic tunnel. The seaplane model had a wing with an aspect ratio of 5.26, a taper ratio of 0.333, and NACA 63A series airfoil sections streamwise. The transport model had a wing with an aspect ratio of 8, a taper ratio of 0.3, and NACA 65A series airfoil sections perpendicular to the quarter-chord line. The effects of flap deflection, flap longitudinal location, and flap sweep were generally investigated for both horizontal-tail-on and horizontal-tail-off configurations. Model force and moment measurements were made for model angles of attack from -5 deg to 14 deg in the Mach number range from 0.70 to 1.075 at Reynolds numbers of 2.95 x 10(exp 6) to 4.35 x 10(exp 6). With proper longitudinal location, wing-lower-surface dive-recovery flaps produced lift and pitching-moment increments that increased with flap deflection. For the transport model a flap located aft on the wing proved to be more effective than one located more forward., both flaps having the same span and approximately the same deflection. For the seaplane model a high horizontal tail provided added effectiveness for the deflected-flap configuration.

Experimental study of effects of forebody geometry on high angle of attack static and dynamic stability and control

NASA Technical Reports Server (NTRS)

Brandon, J. M.; Murri, D. G.; Nguyen, L. T.

1986-01-01

A series of low-speed wind tunnel tests on a generic airplane model with a cylindrical fuselage were made to investigate the effects of forebody shape and fitness ratio, and fuselage/wing proximity on static and dynamic lateral/directional stability. In addition, some preliminary testing to determine the effectiveness of deflectable forebody strakes for high angle of attack yaw control was conducted. During the stability investigation, 11 forebodies were tested including three different cross-sectional shapes with fineness ratios of 2, 3, and 4. In addition, the wing was tested at two longitudinal positions to provide a substantial variation in forebody/wing proximity. Conventional force tests were conducted to determine static stability characteristics, and single-degree-of-freedom free-to-roll tests were conducted to study the wing rock characteristics of the model with the various forebodies. Flow visualization data were obtained to aid in the analysis of the complex flow phenomena involved. The results show that the forebody cross-sectional shape and fineness ratio and forebody/wing proximity can strongly affect both static and dynamic (roll) stability at high angles of attack. These characteristics result from the impact of these factors on forebody vortex development, the behavior of the vortices in sideslip, and their interaction with the wing flow field. Preliminary results from the deflectable strake investigation indicated that forebody flow control using this concept can provide very large yaw control moments at stall and post-stall angles of attack.

Testing and Analysis of a Composite Non-Cylindrical Aircraft Fuselage Structure. Part 1; Ultimate Design Loads

NASA Technical Reports Server (NTRS)

Przekop, Adam; Jegley, Dawn C.; Lovejoy, Andrew E.; Rouse, Marshall; Wu, Hsi-Yung T.

2016-01-01

The Environmentally Responsible Aviation Project aimed to develop aircraft technologies enabling significant fuel burn and community noise reductions. Small incremental changes to the conventional metallic alloy-based 'tube and wing' configuration were not sufficient to achieve the desired metrics. One airframe concept identified by the project as having the potential to dramatically improve aircraft performance was a composite-based hybrid wing body configuration. Such a concept, however, presented inherent challenges stemming from, among other factors, the necessity to transfer wing loads through the entire center fuselage section which accommodates a pressurized cabin confined by flat or nearly flat panels. This paper discusses finite element analysis and testing of a large-scale hybrid wing body center section structure developed and constructed to demonstrate that the Pultruded Rod Stitched Efficient Unitized Structure concept can meet these challenging demands of the next generation airframes. Part I of the paper considers the five most critical load conditions, which are internal pressure only and positive and negative g-loads with and without internal pressure. Analysis results are compared with measurements acquired during testing. Performance of the test article is found to be closely aligned with predictions and, consequently, able to support the hybrid wing body design loads in pristine and barely visible impact damage conditions.

Aeroelastic Analysis of a Flexible Wing Wind Tunnel Model with Variable Camber Continuous Trailing Edge Flap Design

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; Ting, Eric; Lebofsky, Sonia

2015-01-01

This paper presents data analysis of a flexible wing wind tunnel model with a variable camber continuous trailing edge flap (VCCTEF) design for drag minimization tested at the University of Washington Aeronautical Laboratory (UWAL). The wind tunnel test was designed to explore the relative merit of the VCCTEF concept for improved cruise efficiency through the use of low-cost aeroelastic model test techniques. The flexible wing model is a 10%-scale model of a typical transport wing and is constructed of woven fabric composites and foam core. The wing structural stiffness in bending is tailored to be half of the stiffness of a Boeing 757-era transport wing while the torsional stiffness is about the same. This stiffness reduction results in a wing tip deflection of about 10% of the wing semi-span. The VCCTEF is a multi-segment flap design having three chordwise camber segments and five spanwise flap sections for a total of 15 individual flap elements. The three chordwise camber segments can be positioned appropriately to create a desired trailing edge camber. Elastomeric material is used to cover the gaps in between the spanwise flap sections, thereby creating a continuous trailing edge. Wind tunnel data analysis conducted previously shows that the VCCTEF can achieve a drag reduction of up to 6.31% and an improvement in the lift-to-drag ratio (L=D) of up to 4.85%. A method for estimating the bending and torsional stiffnesses of the flexible wingUWAL wind tunnel model from static load test data is presented. The resulting estimation indicates that the stiffness of the flexible wing is significantly stiffer in torsion than in bending by as much as 9 to 1. The lift prediction for the flexible wing is computed by a coupled aerodynamic-structural model. The coupled model is developed by coupling a conceptual aerodynamic tool Vorlax with a finite-element model of the flexible wing via an automated geometry deformation tool. Based on the comparison of the lift curve slope, the lift prediction for the rigid wing is in good agreement with the estimated lift coefficients derived from the wind tunnel test data. Due to the movement of the VCCTEF during the wind tunnel test, uncertainty in the lift prediction due to the indicated variations of the VCCTEF deflection is studied. The results show a significant spread in the lift prediction which contradicts the consistency in the aerodynamic measurements, thus suggesting that the indicated variations as measured by the VICON system may not be reliable. The lift prediction of the flexible wing agrees very well with the measured lift curve for the baseline configuration. The computed bending deflection and wash-out twist of the flexible wing also match reasonably well with the aeroelastic deflection measurements. The results demonstrate the validity of the aerodynamic-structural tool for use to analyze aerodynamic performance of flexible wings.

Spanwise morphing trailing edge on a finite wing

NASA Astrophysics Data System (ADS)

Pankonien, Alexander M.; Inman, Daniel J.

2015-04-01

Unmanned Aerial Vehicles are prime targets for morphing implementation as they must adapt to large changes in flight conditions associated with locally varying wind or large changes in mass associated with payload delivery. The Spanwise Morphing Trailing Edge concept locally varies the trailing edge camber of a wing or control surface, functioning as a modular replacement for conventional ailerons without altering the spar box. Utilizing alternating active sections of Macro Fiber Composites (MFCs) driving internal compliant mechanisms and inactive sections of elastomeric honeycombs, the SMTE concept eliminates geometric discontinuities associated with shape change, increasing aerodynamic performance. Previous work investigated a representative section of the SMTE concept and investigated the effect of various skin designs on actuation authority. The current work experimentally evaluates the aerodynamic gains for the SMTE concept for a representative finite wing as compared with a conventional, articulated wing. The comparative performance for both wings is evaluated by measuring the drag penalty associated with achieving a design lift coefficient from an off-design angle of attack. To reduce experimental complexity, optimal control configurations are predicted with lifting line theory and experimentally measured control derivatives. Evaluated over a range of off-design flight conditions, this metric captures the comparative capability of both concepts to adapt or "morph" to changes in flight conditions. Even with this simplistic model, the SMTE concept is shown to reduce the drag penalty due to adaptation up to 20% at off-design conditions, justifying the increase in mass and complexity and motivating concepts capable of larger displacement ranges, higher fidelity modelling, and condition-sensing control.

Wing walls for enhancing the seismic performance of reinforced concrete frame structures

NASA Astrophysics Data System (ADS)

Yang, Weisong; Guo, Xun; Xu, Weixiao; Yuan, Xin

2016-06-01

A building retrofitted with wing walls in the bottom story, which was damaged during the 2008 M8.0 Wenchuan earthquake in China, is introduced and a corresponding 1/4 scale wing wall-frame model was subjected to shake table motions to study the seismic behavior of this retrofitted structural system. The results show that wing walls can effectively protect columns from damage by moving areas that bear reciprocating tension and compression to the sections of the wing walls, thus achieving an extra measure of seismic fortification. A `strong column-weak beam' mechanism was realized, the flexural rigidity of the vertical member was strengthened, and a more uniform distribution of deformation among all the stories was measured. In addition, the joint between the wing walls and the beams suffered severe damage during the tests, due to an area of local stress concentration. A longer area of intensive stirrup is suggested in the end of the beams.

Effect of pylon cross-sectional geometries on propulsion integration for a low-wing transport

NASA Technical Reports Server (NTRS)

Ingraldi, Anthony M.; Naik, Dinesh A.; Pendergraft, Odis C., Jr.

1993-01-01

An experimental program was conducted in the Langley 16-Foot Transonic Tunnel to evaluate the performance effects of various types of pylons on a 1/17th-scale, low-wing transport model. The model wing was designed for cruise at a Mach number of 0.77 and a lift coefficient of 0.55. The pylons were tested at two wing semispan locations over a range of toe-in angles. The effects of toe-in angle were found to be minimal, but the variation in geometry had a more pronounced effect on the lift characteristics of the model. A pylon whose maximum thickness occurred at the wing trailing edge, known as a compression pylon, proved to be the best choice in terms of retaining the flow characteristics of the wing without pylons. Practical considerations such as structural viability may necessitate modification of the compression pylon concept in order to take advantage of its apparent benefits.

CFD Simulation of a Wing-In-Ground-Effect UAV

NASA Astrophysics Data System (ADS)

Lao, C. T.; Wong, E. T. T.

2018-05-01

This paper reports a numerical analysis on a wing section used for a Wing-In-Ground-Effect (WIG) unmanned aerial vehicle (UAV). The wing geometry was created by SolidWorks and the incompressible Reynolds-averaged Navier-Stokes (RANS) equations were solved with the Spalart–Allmaras turbulence model using CFD software ANSYS FLUENT. In FLUENT, the Spalart-Allmaras model has been implemented to use wall functions when the mesh resolution is not sufficiently fine. This might make it the best choice for relatively crude simulations on coarse meshes where accurate turbulent flow computations are not critical. The results show that the lift coefficient and lift-drag ratio derived excellent performance enhancement by ground effect. However, the moment coefficient shows inconsistency when the wing is operating in very low altitude - this is owing to the difficulty on the stability control of WIG vehicle. A drag polar estimation based on the analysis also indicated that the Oswald (or span) efficiency of the wing was improved by ground effect.

Vocational Education for Special Groups. Sixth Yearbook.

ERIC Educational Resources Information Center

Wall, James E., Ed.

Issues, concepts, and strategies that impact directly on the ability of vocational education to deliver its services to special groups are the focus of this yearbook. Chapters by 24 different authors are divided into three sections. Section 1 provides an overview of special groups, how special groups evolved, their underlying structure and…

The Principal and Fiscal Management. Elementary Principal Series No. 6.

ERIC Educational Resources Information Center

Walters, James K.; Marconnit, George D.

The sixth of six volumes in the "Elementary Principal Series," this booklet is designed to help principals develop sound fiscal management strategies at the building level. The first section reviews Indiana statutory provisions for handling extracurricular and booster group funds. The second section presents guidelines for managing…

Self-Excited Roll Oscillations of Non-Slender Wings

DTIC Science & Technology

2010-03-01

on low sweep delta wings ( Yavuz et al. 2004; Taylor and Gursul 2004). Seeding was provided by a smoke machine placed in the low- speed section of...NV. Yavuz , M.M., Elkhoury, M., Rockwell, D., 2004, “Near-surface topology and flow structure on a delta wing”, AIAA Journal, vol. 42, no. 2, pp

Wing Leading Edge Debris Analysis

NASA Technical Reports Server (NTRS)

Shah, Sandeep; Jerman, Gregory

2004-01-01

This is a slide presentation showing the Left Wing Leading Edge (WLE) heat damage observations: Heavy "slag" deposits on select RCC panels. Eroded and knife-edged RCC rib sections. Excessive overheating and slumping of carrier panel tiles. Missing or molten attachment bolts but intact bushing. Deposit mainly on "inside" RCC panel. Deposit on some fractured RCC surface

Evaluation of Blended Wing-Body Combinations with Curved Plan Forms at Mach Numbers Up to 3.50

NASA Technical Reports Server (NTRS)

Holdaway, George H.; Mellenthin, Jack A.

1960-01-01

This investigation is a continuation of the experimental and theoretical evaluation of the effects of wing plan-form variations on the aerodynamic performance characteristics of blended wing-body combinations. The present report compares previously tested straight-edged delta and arrow models which have leading-edge sweeps of 59.04 and 70-82 deg., respectively, with related models which have plan forms with curved leading and trailing edges designed to result in the same average sweeps in each case. All the models were symmetrical, without camber, and were generally similar having the same span, length, and aspect ratios. The wing sections had an average value of maximum thickness ratio of about 4 percent of the local wing chords in a streamwise direction. The wing sections were computed by varying their shapes along with the body radii (blending process) to match the selected area distribution and the given plan form. The models were tested with transition fixed at Reynolds numbers of roughly 4,000,000 to 9,000,000, based on the mean aerodynamic chord of the wing. The characteristic effect of the wing curvature of the delta and arrow models was an increase at subsonic and transonic speeds in the lift-curve slopes which was partially reflected in increased maximum lift-drag ratios. Curved edges were not evaluated on a diamond plan form because a preliminary investigation indicated that the curvature considered would increase the supersonic zero-lift wave drag. However, after the test program was completed, a suitable modification for the diamond plan form was discovered. The analysis presented in the appendix indicates that large reductions in the zero-lift wave drag would be obtained at supersonic Mach numbers if the leading- and trailing-edge sweeps are made to differ by indenting the trailing edge and extending the root of the leading edge.

Proceedings of the NASTRAN (Tradename) Users’ Colloquium (8th) Held in Greenbelt, Maryland on 30-31 October 1979

DTIC Science & Technology

1980-05-01

36 wing were replaced by a six foot extension and winglet on the 28/29 wing (see Figures 1 & 2). The outward appearance of the 28/29 wing in the...in NASA TMX-3428 (Ref. 1). This model was later updated in the outboard section with the six foot extension and winglet attachment structure. Sizing...incorporated to provide stiffness and an internal lo3d path for forces developed by the winglet , since the winglet was mounted very near the trailing

Numerical simulation of aerodynamic characteristics of multi-element wing with variable flap

NASA Astrophysics Data System (ADS)

Lv, Hongyan; Zhang, Xinpeng; Kuang, Jianghong

2017-10-01

Based on the Reynolds averaged Navier-Stokes equation, the mesh generation technique and the geometric modeling method, the influence of the Spalart-Allmaras turbulence model on the aerodynamic characteristics is investigated. In order to study the typical configuration of aircraft, a similar DLR-F11 wing is selected. Firstly, the 3D model of wing is established, and the 3D model of plane flight, take-off and landing is established. The mesh structure of the flow field is constructed and the mesh is generated by mesh generation software. Secondly, by comparing the numerical simulation with the experimental data, the prediction of the aerodynamic characteristics of the multi section airfoil in takeoff and landing stage is validated. Finally, the two flap deflection angles of take-off and landing are calculated, which provide useful guidance for the aerodynamic characteristics of the wing and the flap angle design of the wing.

Structural Testing of a Stitched/Resin Film Infused Graphite-Epoxy Wing Box

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.; Bush, Harold G.

2001-01-01

The results of a series of tests conducted at the NASA Langley Research Center to evaluate the behavior of an all-composite full-scale wing box are presented. The wing box is representative of a section of a 220-passenger commercial transport aircraft wing box and was designed and constructed by The Boeing Company as part of the NASA Advanced Subsonics Technology (AST) program. The semi-span wing was fabricated from a graphite-epoxy material system with cover panels and spars held together using Kevlar stitches through the thickness. No mechanical fasteners were used to hold the stiffeners to the skin of the cover panels. Tests were conducted with and without low-speed impact damage, discrete source damage and repairs. Up-bending, down-bending and brake roll loading conditions were applied. The structure with non-visible impact damage carried 97% of Design Ultimate Load prior to failure through a lower cover panel access hole.

Structural Response and Failure of a Full-Scale Stitched Graphite-Epoxy Wing

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.; Lovejoy, Andrew E.; Bush, Harold G.

2001-01-01

Analytical and experimental results of the test for an all-composite full-scale wing box are presented. The wing box is representative of a section of a 220-passenger commercial transport aircraft wing box and was designed and constructed by The Boeing Company as part of the NASA Advanced Subsonics Technology (AST) program. The semi-span wing was fabricated from a graphite-epoxy material system with cover panels and spars held together using Kevlar stitches through the thickness. No mechanical fasteners were used to hold the stiffeners to the skin of the cover panels. Tests were conducted with and without low-speed impact damage, discrete source damage and repairs. Up-bending down-bending and brake roll loading conditions were applied. The structure with nonvisible impact damage carried 97% of Design Ultimate Load prior to failure through a lower cover panel access hole. Finite element and experimental results agree for the global response of the structure.

The Design of Airplane Wing Ribs

NASA Technical Reports Server (NTRS)

Newlin, J A; Trayer, George W

1931-01-01

The purpose of this investigation was to obtain information for use in the design of truss and plywood forms, particularly with reference to wing ribs. Tests were made on many designs of wing ribs, comparing different types in various sizes. Many tests were also made on parallel-chord specimens of truss and plywood forms in place of the actual ribs and on parts of wing ribs, such as truss diagonals and sections of cap strips. It was found that for ribs of any size or proportions, when they were designed to obtain a well-balanced construction and were carefully manufactured, distinct types are of various efficiencies; the efficiency is based on the strength per unit of weight. In all types of ribs the heavier are the stronger per unit of weight. Reductions in the weight of wing ribs are accompanied even in efficient designs by a much greater proportional reduction in strength.

Evaluation of the Structural Response and Failure of a Full-Scale Stitched Graphite-Epoxy Wing

NASA Astrophysics Data System (ADS)

Jegley, Dawn C.; Bush, Harold G.; Lovejoy, Andrew E.

2001-01-01

Analytical and experimental results for an all-composite full-scale wing box are presented. The wing box is representative of a section of a 220-passenger commercial transport aircraft wing box and was designed and constructed by The Boeing Company as part of the NASA Advanced Subsonics Technology (AST) program. The semi-span wing was fabricated from a graphite-epoxy material system with cover panels and spars held together using Kevlar stitches through the thickness. No mechanical fasteners were used to hold the stiffeners to the skin of the cover panels. Tests were conducted with and without low-speed impact damage, discrete source damage and repairs. Upbending, down-bending and brake roll loading conditions were applied. The structure with nonvisible impact damage carried 97% of Design Ultimate Load prior to failure through a lower cover panel access hole. Finite element and experimental results agree for the global response of the structure.

An application of neural network for Structural Health Monitoring of an adaptive wing with an array of FBG sensors

NASA Astrophysics Data System (ADS)

Mieloszyk, Magdalena; Krawczuk, Marek; Skarbek, Lukasz; Ostachowicz, Wieslaw

2011-07-01

This paper presents an application of neural networks to determinate the level of activation of shape memory alloy actuators of an adaptive wing. In this concept the shape of the wing can be controlled and altered thanks to the wing design and the use of integrated shape memory alloy actuators. The wing is assumed as assembled from a number of wing sections that relative positions can be controlled independently by thermal activation of shape memory actuators. The investigated wing is employed with an array of Fibre Bragg Grating sensors. The Fibre Bragg Grating sensors with combination of a neural network have been used to Structural Health Monitoring of the wing condition. The FBG sensors are a great tool to control the condition of composite structures due to their immunity to electromagnetic fields as well as their small size and weight. They can be mounted onto the surface or embedded into the wing composite material without any significant influence on the wing strength. The paper concentrates on analysis of the determination of the twisting moment produced by an activated shape memory alloy actuator. This has been analysed both numerically using the finite element method by a commercial code ABAQUS® and experimentally using Fibre Bragg Grating sensor measurements. The results of the analysis have been then used by a neural network to determine twisting moments produced by each shape memory alloy actuator.

Surface-Pressure and Flow-Visualization Data at Mach Number of 1.60 for Three 65 deg Delta Wings Varying in Leading-Edge Radius and Camber

NASA Technical Reports Server (NTRS)

McMillin, S. Naomi; Bryd, James E.; Parmar, Devendra S.; Bezos-OConnor, Gaudy M.; Forrest, Dana K.; Bowen, Susan

1996-01-01

An experimental investigation of the effect of leading-edge radius, camber, Reynolds number, and boundary-layer state on the incipient separation of a delta wing at supersonic speeds was conducted at the Langley Unitary Plan Wind Tunnel at Mach number of 1.60 over a free-stream Reynolds number range of 1 x 106 to 5 x 106 ft-1. The three delta wing models examined had a 65 deg swept leading edge and varied in cross-sectional shape: a sharp wedge, a 20:1 ellipse, and a 20:1 ellipse with a -9.750 circular camber imposed across the span. The wings were tested with and without transition grit applied. Surface-pressure coefficient data and flow-visualization data indicated that by rounding the wing leading edge or cambering the wing in the spanwise direction, the onset of leading-edge separation on a delta wing can be raised to a higher angle of attack than that observed on a sharp-edged delta wing. The data also showed that the onset of leading-edge separation can be raised to a higher angle of attack by forcing boundary-layer transition to occur closer to the wing leading edge by the application of grit or the increase in free-stream Reynolds number.

Aerodynamics power consumption for mechanical flapping wings undergoing flapping and pitching motion

NASA Astrophysics Data System (ADS)

Razak, N. A.; Dimitriadis, G.; Razaami, A. F.

2017-07-01

Lately, due to the growing interest in Micro Aerial Vehicles (MAV), interest in flapping flight has been rekindled. The reason lies in the improved performance of flapping wing flight at low Reynolds number regime. Many studies involving flapping wing flight focused on the generation of unsteady aerodynamic forces such as lift and thrust. There is one aspect of flapping wing flight that received less attention. The aspect is aerodynamic power consumption. Since most mechanical flapping wing aircraft ever designed are battery powered, power consumption is fundamental in improving flight endurance. This paper reports the results of experiments carried out on mechanical wings under going active root flapping and pitching in the wind tunnel. The objective of the work is to investigate the effect of the pitch angle oscillations and wing profile on the power consumption of flapping wings via generation of unsteady aerodynamic forces. The experiments were repeated for different airspeeds, flapping and pitching kinematics, geometric angle of attack and wing sections with symmetric and cambered airfoils. A specially designed mechanical flapper modelled on large migrating birds was used. It will be shown that, under pitch leading conditions, less power is required to overcome the unsteady aerodnamics forces. The study finds less power requirement for downstroke compared to upstroke motion. Overall results demonstrate power consumption depends directly on the unsteady lift force.

Preliminary development of a wing in ground effect vehicle

NASA Astrophysics Data System (ADS)

Abidin, Razali; Ahamat, Mohamad Asmidzam; Ahmad, Tarmizi; Saad, Mohd Rasdan; Hafizi, Ezzat

2018-02-01

Wing in ground vehicle is one of the mode of transportation that allows high speed movement over water by travelling few meters above the water level. Through this manouver strategy, a cushion of compressed air exists between the wing in ground vehicle wings and water. This significantly increase the lift force, thus reducing the necessity in having a long wing span. Our project deals with the development of wing in ground vehicle with the capability of transporting four people. The total weight of this wing in ground vehicle was estimated at 5.4 kN to enable the prediction on required wing area, minimum takeoff velocity, drag force and engine power requirement. The required takeoff velocity is decreases as the lift coefficient increases, and our current mathematical model shows the takeoff velocity at 50 m/s avoid the significant increase in lift coefficient for the wing area of 5 m2. At the velocity of 50 m/s, the drag force created by this wing in ground vehicle is well below 1 kN, which required a 100-120 kW of engine power if the propeller has the efficiency of 0.7. Assessment on the stresses and deflection of the hull structural indicate the capability of plywood to withstand the expected load. However, excessive deflection was expected in the rear section which requires a minor structural modification. In the near future, we expect that the wind tunnel tests of this wing in ground vehicle model would enable more definite prediction on the important parameters related to its performance.

Nanostructured Antireflective and Thermoisolative Cicada Wings.

PubMed

Morikawa, Junko; Ryu, Meguya; Seniutinas, Gediminas; Balčytis, Armandas; Maximova, Ksenia; Wang, Xuewen; Zamengo, Massimiliano; Ivanova, Elena P; Juodkazis, Saulius

2016-05-10

Inter-related mechanical, thermal, and optical macroscopic properties of biomaterials are defined at the nanoscale by their constituent structures and patterns, which underpin complex functions of an entire bio-object. Here, the temperature diffusivity of a cicada (Cyclochila australasiae) wing with nanotextured surfaces was measured using two complementary techniques: a direct contact method and IR imaging. The 4-6-μm-thick wing section was shown to have a thermal diffusivity of α⊥ = (0.71 ± 0.15) × 10(-7) m(2)/s, as measured by the contact temperature wave method along the thickness of the wing; it corresponds to the inherent thermal property of the cuticle. The in-plane thermal diffusivity value of the wing was determined by IR imaging and was considerably larger at α∥ = (3.6 ± 0.2) × 10(-7) m(2)/s as a result of heat transport via air. Optical properties of wings covered with nanospikes were numerically simulated using an accurate 3D model of the wing pattern and showed that light is concentrated between spikes where intensity is enhanced by up to 3- to 4-fold. The closely packed pattern of nanospikes reduces the reflectivity of the wing throughout the visible light spectrum and over a wide range of incident angles, hence acting as an antireflection coating.

Perceived parental and peer disapproval toward substances: influences on adolescent decision-making.

PubMed

Sawyer, Thomas M; Stevenson, John F

2008-11-01

This study investigated the relative influence of perceived parent and peer disapproval for using drugs on youth intentions to use drugs. In a cross-sectional design, sixth and eighth grade students (N = 1,649) completed surveys that included measures of parent disapproval, peer disapproval, and intentions to use drugs in the future. Parent influences were more salient for sixth graders, whereas peer influences were predominant for eighth graders. Peer disapproval was significantly evident in the sixth grade sample, as was parent disapproval in the eighth grade sample. Additionally, girls' drug use intentions were higher than were boys'. These findings suggest that parents can have a robust protective role over and above peer influences and that girls' intentions to use substances deserve increased attention. Editors' Strategic Implications: These findings, if replicated, should help practitioners develop developmentally appropriate strategies and programs for substance use prevention.

Full-scale Wind-tunnel to Determine a Satisfactory Location for a Service Pitot-static Tube on a Low-wing Monoplane

NASA Technical Reports Server (NTRS)

Parsons, John F

1936-01-01

Surveys of the air flow over the upper surface of four different airfoils were made in the full-scale wind tunnel to determine a satisfactory location for a fixed Pitot-static tube on a low-wing monoplane. The selection was based on small interference errors, less than 5 percent, and on a consideration of structural and ground handling problems. The most satisfactory location on the airfoils without flaps that were investigated was 10 percent of the chord aft and 25 percent of the chord above the trailing edge of a section approximately 40 percent of the semispan inboard of the wing tip. No satisfactory location was found near the wing when the flaps were deflected.

Wing spar stress charts and wing truss proportions

NASA Technical Reports Server (NTRS)

Warner, Edward P

1926-01-01

In order to simplify the calculation of beams continuous over three supports, a series of charts have been calculated giving the bending moments at all the critical points and the reactions at all supports for such members. Using these charts as a basis, calculations of equivalent bending moments, representing the total stresses acting in two bay-wing trusses of proportions varying over a wide range, have been determined, both with and without allowance for column effect. This leads finally to the determination of the best proportions for any particular truss or the best strut locations in any particular airplane. The ideal proportions are found to vary with the thickness of the wing section used, the aspect ratio, and the ratio of gap to chord.

[Transverse folding and the evolution of hind wings in beetles (Insecta, Coleoptera)].

PubMed

Fedorenko, D N

2013-01-01

Strong intensification of the protective function of the fore wing in Coleoptera has made their flight apparatus a posteromotoric one and invited an apparatus responsible for folding the hindwings beneath the elytra to develop. Folding apparatus could hardly develop without higher deformability of veins or their parts, which diminished strength properties of the wing support. The effect was stressed by folds that intersected veins. Organization of the folds into a system confined this negative influence to a few wing regions and some veinal sections. This having happened, wing support and folding pattern evolved interrelated, the former into being more flexible, with no or minimum loss of rigidity, and the latter towards being less harmful for the supporting elements, especially axial ones. Monofunctionality, together with very simple structure and little specialization of constituent parts, made the folding pattern very labile during evolution. The folding pattern evolved more rapidly than wing venation, thus defining transformations of the latter. Evolutionary conservatism of wing venation stemmed from that many veins were strongly specialized in performing two conflicting functions. An adaptive compromise was necessary for the conflict to be solved, which determined the wing to orthogenetic development. The main evolutionary trends for wing venation and folding pattern were those towards simplification and a higher complexity, respectively. The beetle wing has passed through two main evolutionary stages. Among them, the first resulted in the development of the "Archostemata" wing type, the second started from the "cantharoid" structural plan. The main evolutionary factors were the infancies of wing posteromotorism at the first stage while the wing strongly influenced by size evolution, with the main trend towards miniaturization, at the second. The archostematan and "cantharoid" morphofunctional wing types differ fundamentally. In the wing of the former kind, folding and flight apparatus, because of considerably overlapping supporting systems, constitute a lasting coadaptive ensemble, with only minor deviations from the ground-plan occurring through evolution. The uprise of the "cantharoid" wing type was an upgrade of morpho-functional organization. The region of maximum transverse deformations having been extruded from the remigium basal part, chief supporting axes of the wing increased their rigid properties. The supporting systems of the two wing apparatus became more autonomous, having been separated. This expanded the adaptive zone for the wing strongly, which a great variety of derived wing types have emerged from.

Pacific Northwest Laboratory annual report for 1973 to the USAEC Division of Biomedical and Environmental Research. Part 2. Ecological sciences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vaughan, B.E.

1974-01-01

Twenty-one sections of the sixth annual report on research programs related to land and aquatic ecosystems and to the behavior of pollutants and radioactive contaminants in such ecosystems are presented. A separate abstract was prepared for each section. (LCL)

Aerodynamic Characteristics of a 0.5-Scale Model of the Fairchild XSAM-N-2 Lark Missile at High Subsonic Speeds

NASA Technical Reports Server (NTRS)

Martin, Andrew; Hunter, Harlo A.

1949-01-01

An investigation was conducted to determine the longitudinal- and lateral-stability characteristics of a 0.5-scale moue1 of the Fairchild Lark missile, The model was tested with 0 deg and with 22.5 deg of roll. Three horizontal wings having NACA 16-009, 16-209, and 64A-209 sections were tested. Pressures were measured on both pointed and blunt noses. The wind-tunnel-test data indicate that rolling the missile 22.5 deg. had no serious effect on the static longitudinal stability. The desired maneuvering acceleration could not be attained with any of the horizontal wings tested, even with the horizontal wing flaps deflected 50 deg. The flaps on the 64A-209 wing (with small trailing-edge angles and flat sides) were effective at all flap deflections, while the flaps on the 16-series wings (with large trailing-edge angles) lost effectiveness at small flap deflections. The data showed that rolling moment existed when the vertical wing flaps were deflected with the model at other than zero angle of attack. A similar rolling moment probably would be found . with the horizontal wing flaps deflected and the model yawed.

Experimental study of the interaction between the wing of a subsonic aircraft and a nacelle of a high by-pass ratio engine

NASA Technical Reports Server (NTRS)

Levart, P.

1981-01-01

The oncoming of a new generation of subsonic transport aircraft (with supercritical wing and high by-pass ratio turbofans) led to an experimental study of wing nacelle jet pylon interference in transonic flow. To this end, a test set-up was developed at the ONERA S3Ch wind tunnel. The nacelle models represent a turbofan by means of two compressed air jets. The scale is 1/18.5. The nacelles are fixed on a thrust balance measuring afterbody thrust and discharge coefficients. The wing is located between the sidewalls of the test section. Pressures are measured through 456 holes located on 8 airfoils. Drag coefficient of the wing is obtained by wake survey. The following parameters can vary (1) wing/nacelle position; (2) upstream Mach number (from 0.3 to 0.8); (3) jet pressure ratio; (4) with/without pylon and (5) type of nacelle. Wing nacelle interference can be studied by means of total thrust drag analysis as a functon of the various parameters. The test set-up is described and examples of results are presented.

Methods for In-Flight Wing Shape Predictions of Highly Flexible Unmanned Aerial Vehicles: Formulation of Ko Displacement Theory

NASA Technical Reports Server (NTRS)

Ko, William L.; Fleischer, Van Tran

2010-01-01

The Ko displacement theory is formulated for a cantilever tubular wing spar under bending, torsion, and combined bending and torsion loading. The Ko displacement equations are expressed in terms of strains measured at multiple sensing stations equally spaced on the surface of the wing spar. The bending and distortion strain data can then be input to the displacement equations to calculate slopes, deflections, and cross-sectional twist angles of the wing spar at the strain-sensing stations for generating the deformed shapes of flexible aircraft wing spars. The displacement equations have been successfully validated for accuracy by finite-element analysis. The Ko displacement theory that has been formulated could also be applied to calculate the deformed shape of simple and tapered beams, plates, and tapered cantilever wing boxes. The Ko displacement theory and associated strain-sensing system (such as fiber optic sensors) form a powerful tool for in-flight deformation monitoring of flexible wings and tails, such as those often employed on unmanned aerial vehicles. Ultimately, the calculated displacement data can be visually displayed in real time to the ground-based pilot for monitoring the deformed shape of unmanned aerial vehicles during flight.

Pathfinder-Plus flight in Hawaii

NASA Technical Reports Server (NTRS)

2002-01-01

Pathfinder-Plus flight in Hawaii June 2002 AeroVironment's Pathfinder-Plus solar-powered flying wing recently flew a three-flight demonstration of its ability to relay third-generation cell phone and video signals as well as provide Internet linkage. The two pods underneath the center section of the wing carried the advanced two-way telecom package, developed by Japanese telecommunications interests.

Biomimetic optimization research on wind noise reduction of an asymmetric cross-section bar.

PubMed

Zhang, Yingchao; Meng, Weijiang; Fan, Bing; Tang, Wenhui

2016-01-01

In this paper, we used the principle of biomimetics to design two-dimensional and three-dimensional bar sections, and used computational fluid dynamics software to numerically simulate and analyse the aerodynamic noise, to reduce drag and noise. We used the principle of biomimetics to design the cross-section of a bar. An owl wing shape was used for the initial design of the section geometry; then the feathered form of an owl wing, the v-shaped micro-grooves of a shark's skin, the tubercles of a humpback whale's flipper, and the stripy surface of a scallop's shell were used to inspire surface features, added to the initial section and three-dimensional shape. Through computational aeroacoustic simulations, we obtained the aerodynamic characteristics and the noise levels of the models. These biomimetic models dramatically decreased noise levels.

Prediction of static aerodynamic characteristics for slender bodies alone and with lifting surfaces to very high angles of attack

NASA Technical Reports Server (NTRS)

Jorgensen, L. H.

1977-01-01

An engineering-type method is presented for computing normal-force and pitching-moment coefficients for slender bodies of circular and noncircular cross section alone and with lifting surfaces. In this method, a semi-empirical term representing viscous-separation crossflow is added to a term representing potential-theory crossflow. For many bodies of revolution, computed aerodynamic characteristics are shown to agree with measured results for investigated free-stream Mach numbers from 0.6 to 2.9. The angles of attack extend from 0 deg to 180 deg for M = 2.9 from 0 deg to 60 deg for M = 0.6 to 2.0. For several bodies of elliptic cross section, measured results are also predicted reasonably well over the investigated Mach number range from 0.6 to 2.0 and at angles of attack from 0 deg to 60 deg. As for the bodies of revolution, the predictions are best for supersonic Mach numbers. For body-wing and body-wing-tail configurations with wings of aspect ratios 3 and 4, measured normal-force coefficients and centers are predicted reasonably well at the upper test Mach number of 2.0. Vapor-screen and oil-flow pictures are shown for many body, body-wing and body-wing-tail configurations. When spearation and vortex patterns are asymmetric, undesirable side forces are measured for the models even at zero sideslip angle. Generally, the side-force coefficients decrease or vanish with the following: increase in Mach number, decrease in nose fineness ratio, change from sharp to blunt nose, and flattening of body cross section (particularly the body nose).

a New Efficient Control Method for Blended Wing Body

NASA Astrophysics Data System (ADS)

Wu, Wenhua; Chen, Dehua; Qin, Ning; Peng, Xin; Tang, Xinwu

The blended wing body (BWB) is the hottest one of the aerodynamic shapes of next generation airliner because of its' high lift-drag ratio, but there are still some flaws that cut down its aerodynamical performance. One of the most harmful flaws is the low efficiency of elevator and direction rudder, this makes the BWB hard to be controlled. In this paper, we proposed a new control method to solve this problem by morphing wing—that is, to control the BWB only by changing its wing shape but without any rudder. The pitching moments, rolling moments and yawing moments are plotted versus the parameters section and the wing shape in figures and are discussed in the paper. The result shows that the morphing wing can control the moments of BWB more precisely and in wider range. The pitching moments, rolling moments and yawing moments increases or decreases linearly or almost linearly, with the value of the selected parameters. These results show that using morphing wing is an excellent aerodynamic control way for a BWB craft.

Finite element analysis of high aspect ratio wind tunnel wing model: A parametric study

NASA Astrophysics Data System (ADS)

Rosly, N. A.; Harmin, M. Y.

2017-12-01

Procedure for designing the wind tunnel model of a high aspect ratio (HAR) wing containing geometric nonlinearities is described in this paper. The design process begins with identification of basic features of the HAR wing as well as its design constraints. This enables the design space to be narrowed down and consequently, brings ease of convergence towards the design solution. Parametric studies in terms of the spar thickness, the span length and the store diameter are performed using finite element analysis for both undeformed and deformed cases, which respectively demonstrate the linear and nonlinear conditions. Two main criteria are accounted for in the selection of the wing design: the static deflections due to gravitational loading should be within the allowable margin of the size of the wind tunnel test section and the flutter speed of the wing should be much below the maximum speed of the wind tunnel. The findings show that the wing experiences a stiffness hardening effect under the nonlinear static solution and the presence of the store enables significant reduction in linear flutter speed.

Design charts for predicting downwash angles and wake characteristics behind plain and flapped wings

NASA Technical Reports Server (NTRS)

Silverstein, Abe; Katzoff, S

1939-01-01

Equations and design charts are given for predicting the downwash angles and the wake characteristics for power-off conditions behind plain and flapped wings of the types used in modern design practice. The downwash charts cover the cases of elliptical wings and wings of taper ratios 1, 2, 3, and 5, with aspect ratios of 6, 9, and 12, having flaps covering 0, 40, 70, and 100 percent of the span. Curves of the span load distributions for all these cases are included. Data on the lift and the drag of flapped airfoil sections and curves for finding the contribution of the flap to the total wing lift for different types of flap and for the entire range of flap spans are also included. The wake width and the distribution of dynamic pressure across the wake are given in terms of the profile-drag coefficient and the distance behind the wing. A method of estimating the wake position is also given. The equations and charts are based on theory that has been shown in a previous report to be in agreement with experiment.

Spanwise lift distributions and wake velocity surveys of a semi-span wing with a discontinuous twist

NASA Technical Reports Server (NTRS)

Kumagai, Hiroyuki

1989-01-01

A wind tunnel test was conducted in the NASA-Ames 7 x 10 ft wind tunnel to investigate the lift distribution on a semispan wing with a discontinuous change in spanwise twist. The semispan wing had a tip with an adjustable pitch angle independent on the inboard section pitch angle simulating the free tip rotor blade when its free tip is at a deflected position. The spanwise lift distribution over the wing and the tip were measured and three component velocity surveys behind the wing were obtained with a 3-D laser Doppler velocimeter (LV) with the wing at one angle of attack and the tip deflected at different pitch angles. A six-component internal strain gage balance was also used to measure total forces and moments on the tip. The 3-D lift was computed from the 2-D lift distributions obtained from the LV and from the strain gage balance. The results from both experimental methods are shown to be in agreement with predictions made by a steady, 3-D panel code, VSAERO.

An experimental investigation of three dimensional low speed minimum interference wind tunnel for high lift wings

NASA Technical Reports Server (NTRS)

Shindo, S.; Joppa, R. G.

1980-01-01

As a means to achieve a minimum interference correction wind tunnel, a partially actively controlled test section was experimentally examined. A jet flapped wing with 0.91 m (36 in) span and R = 4.05 was used as a model to create moderately high lift coefficients. The partially controlled test section was simulated using an insert, a rectangular box 0.96 x 1.44 m (3.14 x 4.71 ft) open on both ends in the direction of the tunnel air flow, placed in the University of Washington Aeronautical Laboratories (UWAL) 2.44 x 3.66 m (8 x 12 ft) wind tunnel. A tail located three chords behind the wing was used to measure the downwash at the tail region. The experimental data indicates that, within the range of momentum coefficient examined, it appears to be unnecessary to actively control all four sides of the test section walls in order to achieve the near interference free flow field environment in a small wind tunnel. The remaining wall interference can be satisfactorily corrected by the vortex lattice method.

Finite Element Simulations of Two Vertical Drop Tests of F-28 Fuselage Sections

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Littell, Justin D.; Annett, Martin S.; Haskin, Ian M.

2018-01-01

In March 2017, a vertical drop test of a forward fuselage section of a Fokker F-28 MK4000 aircraft was conducted as part of a joint NASA/FAA project to investigate the performance of transport aircraft under realistic crash conditions. In June 2017, a vertical drop test was conducted of a wing-box fuselage section of the same aircraft. Both sections were configured with two rows of aircraft seats, in a triple-double configuration. A total of ten Anthropomorphic Test Devices (ATDs) were secured in seats using standard lap belt restraints. The forward fuselage section was also configured with luggage in the cargo hold. Both sections were outfitted with two hat racks, each with added ballast mass. The drop tests were performed at the Landing and Impact Research facility located at NASA Langley Research Center in Hampton, Virginia. The measured impact velocity for the forward fuselage section was 346.8-in/s onto soil. The wing-box section was dropped with a downward facing pitch angle onto a sloping soil surface in order to create an induced forward acceleration in the airframe. The vertical impact velocity of the wing-box section was 349.2-in/s. A second objective of this project was to assess the capabilities of finite element simulations to predict the test responses. Finite element models of both fuselage sections were developed for execution in LS-DYNA(Registered Trademark), a commercial explicit nonlinear transient dynamic code. The models contained accurate representations of the airframe structure, the hat racks and hat rack masses, the floor and seat tracks, the luggage in the cargo hold for the forward section, and the detailed under-floor structure in the wing-box section. Initially, concentrated masses were used to represent the inertial properties of the seats, restraints, and ATD occupants. However, later simulations were performed that included finite element representations of the seats, restraints, and ATD occupants. These models were developed to more accurately replicate the seat loading of the floor and to enable prediction of occupant impact responses. Models were executed to generate analytical predictions of airframe responses, which were compared with test data to validate the model. Comparisons of predicted and experimental structural deformation and failures were made. Finally, predicted and experimental soil deformation and crater depths were also compared for both drop test configurations.

A correlation by means of transonic similarity rules of the experimentally determined characteristics of 18 cambered wings of rectangular plan form

NASA Technical Reports Server (NTRS)

Mcdevitt, John B

1953-01-01

The effects of one type of camber on the aerodynamic characteristics of rectangular wings at high subsonic and transonic speeds have been studied by applying the transonic similarity rules to the correlation of experimental data for a series of 18 cambered wings having NACA 63A2XX and 63A4XX sections, aspect ratios from 1 to 4, and thicknesses from 4 to 8 percent. The data were obtained by use of a transonic bump over a Mach number range of 0.6 to 1.1.

Arrow-wing supersonic cruise aircraft structural design concepts evaluation. Volume 3: Sections 12 through 14

NASA Technical Reports Server (NTRS)

Sakata, I. F.; Davis, G. W.

1975-01-01

The design of an economically viable supersonic cruise aircraft requires the lowest attainable structural-mass fraction commensurate with the selected near-term structural material technology. To achieve this goal of minimum structural-mass fraction, various combinations of promising wing and fuselage primary structure were analyzed for the load-temperature environment applicable to the arrow wing configuration. This analysis was conducted in accordance with the design criteria specified and included extensive use of computer-aided analytical methods to screen the candidate concepts and select the most promising concepts for the in-depth structural analysis.

Downwash in Vortex Region Behind Rectangular Half-wing at Mach Number 1.91

NASA Technical Reports Server (NTRS)

Cummings, John L; Haefeli, Rudolph C

1950-01-01

Results of an experimental investigation to determine downwash and wake characteristics in region of trailing vortex system behind a rectangular half-wing at Mach number 1.91 are presented. The wing had a 5-percent thick symmetric diamond cross section beveled to a knife edge at the tip. At small angles of attack, downwash angles were in close agreement with predictions of linearized theory based on the assumption of an undistorted vortex sheet. At higher angles of attack, the flow was greatly influenced by the rolling up of the vortex sheet.

On the aerodynamic forces of flapping finite-wings in forward flight: a numerical study

NASA Astrophysics Data System (ADS)

Gonzalo, Alejandro; Uhlmann, Markus; Garcia-Villalba, Manuel; Flores, Oscar

2017-11-01

We study the flow around two flapping wings in forward flight at a low Reynolds number, Re = 500 , with 3D direct numerical simulations. The flow solver used is TUCAN, an in-house code which solves the Navier-Stokes equations for incompressible flow using an immersed boundary method to model the presence of the wings. The wings are rectangular with a NACA0012 airfoil of chord c as a cross-section. They are located side by side at a distance 0.5 c between their inboard tips. The wings flap with respect to an axis parallel to the streamwise velocity, without pitching. The angle of rotation is defined using a sinusoidal function with a reduced frequency k = 1 and an amplitude such that the maximum height of the outboard tips is c in all cases. We perform several simulations varying the aspect ratio of the wings (AR = 2 and 4) and the distance between the inboard tip of the wings and the axis of rotation (R = 0 , 2 and ∞), the latter case corresponding to wings in heaving motion. In this way we can study the variation of the fictitious forces on the wings and the induced spanwise flows, and their relation to the vortical structures on the wing (i.e. leading edge vortex, trailing edge votex, tip vortices) and the resulting aerodynamic forces. This work was funded by project TRA2013-41103-P (Mineco/Feder UE). The simulations were partially performed at the Steinbuch Centre for Computing, Karlsruhe, whose support is thankfully acknowledged.

Novel Control Effectors for Truss Braced Wing

NASA Technical Reports Server (NTRS)

White, Edward V.; Kapania, Rakesh K.; Joshi, Shiv

2015-01-01

At cruise flight conditions very high aspect ratio/low sweep truss braced wings (TBW) may be subject to design requirements that distinguish them from more highly swept cantilevered wings. High aspect ratio, short chord length and relative thinness of the airfoil sections all contribute to relatively low wing torsional stiffness. This may lead to aeroelastic issues such as aileron reversal and low flutter margins. In order to counteract these issues, high aspect ratio/low sweep wings may need to carry additional high speed control effectors to operate when outboard ailerons are in reversal and/or must carry additional structural weight to enhance torsional stiffness. The novel control effector evaluated in this study is a variable sweep raked wing tip with an aileron control surface. Forward sweep of the tip allows the aileron to align closely with the torsional axis of the wing and operate in a conventional fashion. Aft sweep of the tip creates a large moment arm from the aileron to the wing torsional axis greatly enhancing aileron reversal. The novelty comes from using this enhanced and controllable aileron reversal effect to provide roll control authority by acting as a servo tab and providing roll control through intentional twist of the wing. In this case the reduced torsional stiffness of the wing becomes an advantage to be exploited. The study results show that the novel control effector concept does provide roll control as described, but only for a restricted class of TBW aircraft configurations. For the configuration studied (long range, dual aisle, Mach 0.85 cruise) the novel control effector provides significant benefits including up to 12% reduction in fuel burn.

Numerical analyses of evolution of unsteady flow structures in the wake of flapping starling wing model

NASA Astrophysics Data System (ADS)

Krishnan, Krishnamoorthy; Naqavi, Iftekhar Z.; Gurka, Roi

2017-11-01

Understanding the physics of flapping wings at moderate Reynolds number flows takes on greater importance in the context of avian aerodynamics as well as in the design of miniature-aerial-vehicles. Analyzing the characteristics of wake vortices generated downstream of flapping wings can help to explain the unsteady contribution to the aerodynamics loads. In this study, numerical simulations of flow over a bio-inspired pseudo-2D flapping wing model was conducted to characterize the evolution of unsteady flow structures in the downstream wake of flapping wing. The wing model was based on a European starling's wing and wingbeat kinematics were incorporated to simulate a free-forward flight. The starling's wingbeat kinematics were extracted from experiments conducted in a wind tunnel where freely flying starling was measured using high-speed PIV as well as high-speed imaging yielding a series of kinematic images sampled at 500 Hz. The average chord of the wing section was 6 cm and simulations were carried out at a Reynolds number of 54,000, reduced frequency of 0.17, and Strouhal number of 0.16. Large eddy simulation was performed using a second order, finite difference code ParLES. Characteristics of wake vortex structures during the different phases of the wing strokes were examined. The role of wingbeat kinematics in the configuration of downstream vortex patterns is discussed. Evaluated wake topology and lift-drag characteristics are compared with the starling's wind tunnel results.

Investigations at supersonic speeds of 22 triangular wings representing two airfoil sections for each of 11 apex angles

NASA Technical Reports Server (NTRS)

Love, Eugene S

1949-01-01

Data obtained from wind tunnel investigations of two series of 11 triangular wings conducted at Mach numbers of 1.62, 1.92, and 1.40 to determine the effect of leading-edge shape and to compare actual test values with the nonviscous linear theory are presented. The two series of wings had identical plan forms, a constant thickness ratio of 8 percent, a constant location of maximum-thickness point of 18 percent, and a range of apex half-angles from 10 degrees to forty-five degrees. The first series has an elliptical leading edge and the second series a wedge leading edge. Measurements were made of lift, drag, pitching moment, and pressure distribution, the latter being confined to three wings at one Mach number.

LOFT, TAN650. Camera facing southeast. From left to right: stack ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

LOFT, TAN-650. Camera facing southeast. From left to right: stack in distance, pre-amp wing, dome, north side of loft "service building." Note poured concrete wall of pre-amp wing on lower section; pumice block above. Date: May 2004. INEEL negative no. HD-39-19-3 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Arrow-wing supersonic cruise aircraft structural design concepts evaluation. Volume 1: Sections 1 through 6

NASA Technical Reports Server (NTRS)

Sakata, I. F.; Davis, G. W.

1975-01-01

The structural approach best suited for the design of a Mach 2.7 arrow-wing supersonic cruise aircraft was investigated. Results, procedures, and principal justification of results are presented. Detailed substantiation data are given. In general, each major analysis is presented sequentially in separate sections to provide continuity in the flow of the design concepts analysis effort. In addition to the design concepts evaluation and the detailed engineering design analyses, supporting tasks encompassing: (1) the controls system development; (2) the propulsion-airframe integration study; and (3) the advanced technology assessment are presented.

77 FR 37728 - GMB Mezzanine Capital II, L.P.; Notice Seeking Exemption Under Section 312 of the Small Business...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-22

... SMALL BUSINESS ADMINISTRATION [License No. 05/05-0299] GMB Mezzanine Capital II, L.P.; Notice Seeking Exemption Under Section 312 of the Small Business Investment Act, Conflicts of Interest Notice is hereby given that GMB Mezzanine Capital II, L.P., 50 South Sixth Street, Suite 1460, Minneapolis, MN...

A Voice for all Students: Realizing Gender Equity in Schools. Diversity in the Classroom Series, Number Six.

ERIC Educational Resources Information Center

Pratchler, Joan

This document, the sixth in a series on diversity in the classroom, encourages schools to reflect on and explore current research and practical applications regarding gender issues, both inside and outside the classroom. Section 1, "Introduction," discusses what gender equity is and is not. Section 2, "Gender Equity is…

Don't Stop the Music. Unit of Study on Older Americans. Kindergarten through Sixth Grade.

ERIC Educational Resources Information Center

Oklahoma State Dept. of Education, Oklahoma City.

This guide provides background information and learning activities to help teachers provide educational experiences for elementary students regarding older Americans and the process of aging. There are two major sections. The first section contains a facts-on-aging quiz and discusses facts and myths about older citizens. Examined are feelings and…

A Step by Step Guide for Planning a Japanese Cultural Festival.

ERIC Educational Resources Information Center

Murphy, Carole

Teachers at all academic levels can adapt the design and content of the sixth grade Japanese cultural festival detailed in this learning packet. Material is divided into 2 sections. Section 1 provides a step-by-step guide to planning and conducting the festival. These instructions, based on 5 years of experience, include a detailed planning…

Biological Science: An Ecological Approach. BSCS Green Version. Teacher's Resource Book and Test Item Bank. Sixth Edition.

ERIC Educational Resources Information Center

Biological Sciences Curriculum Study, Colorado Springs.

This book consists of four sections: (1) "Supplemental Materials"; (2) "Supplemental Investigations"; (3) "Test Item Bank"; and (4) "Blackline Masters." The first section provides additional background material related to selected chapters and investigations in the student book. Included are a periodic table of the elements, genetics problems and…

Sold to Dominic for 1 Troy and 3 (24) Fin: An Economic Money System.

ERIC Educational Resources Information Center

Williams, Sandra L.

Arranged in two sections, this paper details a project for incorporating ongoing economics study into a sixth-grade curriculum by creating an imaginary economic system. Section 1 highlights the main activities of the project, which include the following. A money system, based on units of 12 to enhance multiplication skills, was instituted, with…

Study on flow over finite wing with respect to F-22 raptor, Supermarine Spitfire, F-7 BG aircraft wing and analyze its stability performance and experimental values

NASA Astrophysics Data System (ADS)

Ali, Md. Nesar; Alam, Mahbubul

2017-06-01

A finite wing is a three-dimensional body, and consequently the flow over the finite wing is three-dimensional; that is, there is a component of flow in the span wise direction. The physical mechanism for generating lift on the wing is the existence of a high pressure on the bottom surface and a low pressure on the top surface. The net imbalance of the pressure distribution creates the lift. As a by-product of this pressure imbalance, the flow near the wing tips tends to curl around the tips, being forced from the high-pressure region just underneath the tips to the low-pressure region on top. This flow around the wing tips is shown in the front view of the wing. As a result, on the top surface of the wing, there is generally a span wise component of flow from the tip toward the wing root, causing the streamlines over the top surface to bend toward the root. On the bottom surface of the wing, there is generally a span wise component of flow from the root toward the tip, causing the streamlines over the bottom surface to bend toward the tip. Clearly, the flow over the finite wing is three-dimensional, and therefore we would expect the overall aerodynamic properties of such a wing to differ from those of its airfoil sections. The tendency for the flow to "leak" around the wing tips has another important effect on the aerodynamics of the wing. This flow establishes a circulatory motion that trails downstream of the wing; that is, a trailing vortex is created at each wing tip. The aerodynamics of finite wings is analyzed using the classical lifting line model. This simple model allows a closed-form solution that captures most of the physical effects applicable to finite wings. The model is based on the horseshoe-shaped vortex that introduces the concept of a vortex wake and wing tip vortices. The downwash induced by the wake creates an induced drag that did not exist in the two-dimensional analysis. Furthermore, as wingspan is reduced, the wing lift slope decreases, and the induced drag increases, reducing overall efficiency. To complement the high aspect ratio wing case, a slender wing model is formulated so that the lift and drag can be estimated for this limiting case as well. We analyze the stability performance of F-22 raptor, Supermarine Spitfire, F-7 BG Aircraft wing by using experimental method and simulation software. The experimental method includes fabrication of F-22 raptor, Supermarine Spitfire, F-7 BG Aircraft wing which making material is Gamahr wood. Testing this model wing in wind tunnel test and after getting expected data we also compared this value with analyzing software data for furthermore experiment.

Wind-tunnel Investigation of High-lift and Stall-control Devices on a 37 Degree Sweptback Wing of Aspect Ratio 6 at High Reynolds Numbers

NASA Technical Reports Server (NTRS)

Koven, William; Graham, Robert R

1948-01-01

Results are presented of an investigation in the Langley 19-foot pressure tunnel of the longitudinal characteristics of a semispan model wing having 37 degrees sweepback of the leading edge, an aspect ratio of 6, and NACA 641-212 airfoil section perpendicular to the 27-percent-chord line. Several types of stall-control devices including extensible round-nose leading-edge flaps, a leading-edge slat, and a drooped leading edge were investigated; partial- and full-span trailing-edge split and double slotted flaps were also tested. In addition, various combinations of the aforementioned leading- and trailing-edge flaps were investigated. The tests covered a range of Reynolds numbers between 2.00 x 10(6) and 9.35 x 10(6). The wing with or without trailing-edge splity of double slotted flap was longitudinally unstable near maximum lift due to tip stalling. The addition of an outboard half-span leading-edge flap or a leading-edge slat to the plain wing or wing with inboard half-span split flaps eliminated tip stalling and resulted in stable moment variations at the stall. The drooped leading edge, on the other hand, was only effective when used in conjunction with an upper-surface fence. The combination of an outboard leading-edge device and inboard half-span double slotted flap resulted in an undesirable loop in the pitching-moment curve near maximum lift in spite of an inboard stall. The loop is attributed to the section characteristics of the double slotted flap. Air-flow surveys behind the wing indicated that a suitably placed horizontal tail would eliminate the loop in the moment curve.

Theoretical prediction of thick wing and pylon-fuselage-fanpod-nacelle aerodynamic characteristics at subcritical speeds. Part 1: Theory and results

NASA Technical Reports Server (NTRS)

Tulinius, J. R.

1974-01-01

The theoretical development and the comparison of results with data of a thick wing and pylon-fuselage-fanpod-nacelle analysis are presented. The analysis utilizes potential flow theory to compute the surface velocities and pressures, section lift and center of pressure, and the total configuration lift, moment, and vortex drag. The skin friction drag is also estimated in the analysis. The perturbation velocities induced by the wing and pylon, fuselage and fanpod, and nacelle are represented by source and vortex lattices, quadrilateral vortices, and source frustums, respectively. The strengths of these singularities are solved for simultaneously including all interference effects. The wing and pylon planforms, twists, cambers, and thickness distributions, and the fuselage and fanpod geometries can be arbitrary in shape, provided the surface gradients are smooth. The flow through nacelle is assumed to be axisymmetric. An axisymmetric center engine hub can also be included. The pylon and nacelle can be attached to the wing, fuselage, or fanpod.

A computer program to calculate the longitudinal aerodynamic characteristics of upper-surface-blown wing-flap configurations

NASA Technical Reports Server (NTRS)

Mendenhall, M. R.

1978-01-01

A user's manual is presented for a computer program in which a vortex-lattice lifting-surface method is used to model the wing and multiple flaps. The engine wake model consists of a series of closely spaced vortex rings with rectangular cross sections. The jet wake is positioned such that the lower boundary of the jet is tangent to the wing and flap upper surfaces. The two potential flow models are used to calculate the wing-flap loading distribution including the influence of the wakes from up to two engines on the semispan. The method is limited to the condition where the flow and geometry of the configurations are symmetric about the vertical plane containing the wing root chord. The results include total configuration forces and moments, individual lifting-surface load distributions, pressure distributions, flap hinge moments, and flow field calculation at arbitrary field points. The use of the program, preparation of input, the output, program listing, and sample cases are described.

Low-Reynolds Number Aerodynamics of an 8.9 Percent Scale Semispan Swept Wing for Assessment of Icing Effects

NASA Technical Reports Server (NTRS)

Broeren, Andy P.; Woodard, Brian S.; Diebold, Jeffrey M.; Moens, Frederic

2017-01-01

Aerodynamic assessment of icing effects on swept wings is an important component of a larger effort to improve three-dimensional icing simulation capabilities. An understanding of ice-shape geometric fidelity and Reynolds and Mach number effects on the iced-wing aerodynamics is needed to guide the development and validation of ice-accretion simulation tools. To this end, wind-tunnel testing and computational flow simulations were carried out for an 8.9%-scale semispan wing based upon the Common Research Model airplane configuration. The wind-tunnel testing was conducted at the Wichita State University 7 ft x 10 ft Beech wind tunnel from Reynolds numbers of 0.8×10(exp 6) to 2.4×10(exp 6) and corresponding Mach numbers of 0.09 to 0.27. This paper presents the results of initial studies investigating the model mounting configuration, clean-wing aerodynamics and effects of artificial ice roughness. Four different model mounting configurations were considered and a circular splitter plate combined with a streamlined shroud was selected as the baseline geometry for the remainder of the experiments and computational simulations. A detailed study of the clean-wing aerodynamics and stall characteristics was made. In all cases, the flow over the outboard sections of the wing separated as the wing stalled with the inboard sections near the root maintaining attached flow. Computational flow simulations were carried out with the ONERA elsA software that solves the compressible, three-dimensional RANS equations. The computations were carried out in either fully turbulent mode or with natural transition. Better agreement between the experimental and computational results was obtained when considering computations with free transition compared to turbulent solutions. These results indicate that experimental evolution of the clean wing performance coefficients were due to the effect of three-dimensional transition location and that this must be taken into account for future data analysis. This research also confirmed that artificial ice roughness created with rapid-prototype manufacturing methods can generate aerodynamic performance effects comparable to grit roughness of equivalent size when proper care is exercised in design and installation. The conclusions of this combined experimental and computational study contributed directly to the successful implementation of follow-on test campaigns with numerous artificial ice-shape configurations for this 8.9% scale model.

Low-Reynolds Number Aerodynamics of an 8.9 Percent Scale Semispan Swept Wing for Assessment of Icing Effects

NASA Technical Reports Server (NTRS)

Broeren, Andy P.; Woodard, Brian S.; Diebold, Jeffrey M.; Moens, Frederic

2017-01-01

Aerodynamic assessment of icing effects on swept wings is an important component of a larger effort to improve three-dimensional icing simulation capabilities. An understanding of ice-shape geometric fidelity and Reynolds and Mach number effects on the iced-wing aerodynamics is needed to guide the development and validation of ice-accretion simulation tools. To this end, wind-tunnel testing and computational flow simulations were carried out for an 8.9 percent-scale semispan wing based upon the Common Research Model airplane configuration. The wind-tunnel testing was conducted at the Wichita State University 7 by 10 ft Beech wind tunnel from Reynolds numbers of 0.8×10(exp 6) to 2.4×10(exp 6) and corresponding Mach numbers of 0.09 to 0.27. This paper presents the results of initial studies investigating the model mounting configuration, clean-wing aerodynamics and effects of artificial ice roughness. Four different model mounting configurations were considered and a circular splitter plate combined with a streamlined shroud was selected as the baseline geometry for the remainder of the experiments and computational simulations. A detailed study of the clean-wing aerodynamics and stall characteristics was made. In all cases, the flow over the outboard sections of the wing separated as the wing stalled with the inboard sections near the root maintaining attached flow. Computational flow simulations were carried out with the ONERA elsA software that solves the compressible, threedimensional RANS equations. The computations were carried out in either fully turbulent mode or with natural transition. Better agreement between the experimental and computational results was obtained when considering computations with free transition compared to turbulent solutions. These results indicate that experimental evolution of the clean wing performance coefficients were due to the effect of three-dimensional transition location and that this must be taken into account for future data analysis. This research also confirmed that artificial ice roughness created with rapid-prototype manufacturing methods can generate aerodynamic performance effects comparable to grit roughness of equivalent size when proper care is exercised in design and installation. The conclusions of this combined experimental and computational study contributed directly to the successful implementation of follow-on test campaigns with numerous artificial ice-shape configurations for this 8.9 percent scale model.

Aerodynamic forces and flows of the full and partial clap-fling motions in insects

PubMed Central

Sun, Mao

2017-01-01

Most of the previous studies on Weis-Fogh clap-fling mechanism have focused on the vortex structures and velocity fields. Detailed pressure distribution results are provided for the first time in this study to reveal the differences between the full and the partial clap-fling motions. The two motions are studied by numerically solving the Navier–Stokes equations in moving overset grids. The Reynolds number is set to 20, relevant to the tiny flying insects. The following has been shown: (1) During the clap phase, the wings clap together and create a high pressure region in the closing gap between wings, greatly increasing the positive pressure on the lower surface of wing, while pressure on the upper surface is almost unchanged by the interaction; during the fling phase, the wings fling apart and create a low pressure region in the opening gap between wings, greatly increasing the suction pressure on the upper surface of wing, while pressure on the lower surface is almost unchanged by the interaction; (2) The interference effect between wings is most severe at the end of clap phase and the start of the fling phase: two sharp force peaks (8–9 times larger than that of the one-winged case) are generated. But the total force peaks are manifested mostly as drag and barely as lift of the wing, owing to the vertical orientation of the wing section; (3) The wing–wing interaction effect in the partial clap-fling case is much weaker than that in the full clap-fling case, avoiding the generation of huge drag. Compared with a single wing flapping with the same motion, mean lift in the partial case is enhanced by 12% without suffering any efficiency degradation, indicating that partial clap-fling is a more practical choice for tiny insects to employ. PMID:28289562

Composite Bending Box Section Modal Vibration Fault Detection

NASA Technical Reports Server (NTRS)

Werlink, Rudy

2002-01-01

One of the primary concerns with Composite construction in critical structures such as wings and stabilizers is that hidden faults and cracks can develop operationally. In the real world, catastrophic sudden failure can result from these undetected faults in composite structures. Vibration data incorporating a broad frequency modal approach, could detect significant changes prior to failure. The purpose of this report is to investigate the usefulness of frequency mode testing before and after bending and torsion loading on a composite bending Box Test section. This test article is representative of construction techniques being developed for the recent NASA Blended Wing Body Low Speed Vehicle Project. The Box section represents the construction technique on the proposed blended wing aircraft. Modal testing using an impact hammer provides an frequency fingerprint before and after bending and torsional loading. If a significant structural discontinuity develops, the vibration response is expected to change. The limitations of the data will be evaluated for future use as a non-destructive in-situ method of assessing hidden damage in similarly constructed composite wing assemblies. Modal vibration fault detection sensitivity to band-width, location and axis will be investigated. Do the sensor accelerometers need to be near the fault and or in the same axis? The response data used in this report was recorded at 17 locations using tri-axial accelerometers. The modal tests were conducted following 5 independent loading conditions before load to failure and 2 following load to failure over a period of 6 weeks. Redundant data was used to minimize effects from uncontrolled variables which could lead to incorrect interpretations. It will be shown that vibrational modes detected failure at many locations when skin de-bonding failures occurred near the center section. Important considerations are the axis selected and frequency range.

A Transonic Wind-Tunnel Investigation of the Performance and of the Static Stability and Control Characteristics of a Model of a Fighter-Type Airplane which Embodies Partial Body Indentation

NASA Technical Reports Server (NTRS)

Bielat, Ralph P.

1959-01-01

An investigation was conducted to obtain the aerodynamic characteristics of a model of a fighter-type airplane embodying partial body indentation. The wing had an aspect ratio of 4, taper ratio of 0.5, 35 deg sweepback of the 0.25-chord line, and a modified NACA 65A006 airfoil section at the root and a modified NACA 65A004 airfoil section at the tip. The fuselage has been indented in the region of the wing in order to obtain a favorable area distribution. The results reported herein consist of the performance and of the static longitudinal and lateral stability and control characteristics of the complete model. The Mach number range extended from 0.60 to 1.13, and the corresponding Reynolds number based on the wing mean aerodynamic chord varied from 1.77 x 10(exp 6) to 2.15 x 10(exp 6). The drag rise for both the cambered leading edge and symmetrical wing sections occurred at a Mach number of 0.95. Certain local modifications to the body which further improved the distribution of cross-sectional area gave additional reductions in drag at a Mach number of 1.00. The basic configuration indicated a mild pitch-up tendency at lift coefficients near 0.70 for the Mach number range from 0.80 to 0.90; however, the pitch-up instability may not be too objectionable on the basis of dynamic-stability considerations. The basic configuration indicated positive directional stability and positive effective dihedral through the angle-of-attack range and Mach number range with the exception of a region of negative effective dihedral at low lifts at Mach numbers of 1.00 and slightly above.

EC00-0283-4

NASA Image and Video Library

2000-09-18

Technician Marshall MacCready carefully lays a panel of solar cells into place on a wing section of the Helios Prototype flying wing at AeroVironment's Design Development Center in Simi Valley, California. The bi-facial cells, manufactured by SunPower, Inc., of Sunnyvale, California, are among 64,000 solar cells which have been installed on the solar-powered aircraft to provide electricity to its 14 motors and operating systems.

EC00-0283-5

NASA Image and Video Library

2000-09-18

Technician Marshall MacCready carefully lays a panel of solar cells into place on a wing section of the Helios Prototype flying wing at AeroVironment's Design Development Center in Simi Valley, California. More than 1,800 panels containing some 64,000 bi-facial cells, fabricated by SunPower, Inc., of Sunnyvale, California, have been installed on the solar-powered aircraft to provide electricity to its 14 motors and operating systems.

Acoustic tests of augmentor wing model

NASA Technical Reports Server (NTRS)

Goodykoontz, J. H.

1977-01-01

Acoustic and aerodynamic data were obtained for a full-scale section of an augmentor wing. Features of the design included a single-row, multielement nozzle array and acoustically tuned panels placed on the interior surfaces of the augmentor. When the data were extrapolated to a 91,000-kilogram aircraft, the calculated sideline perceived noise levels were approximately the same for either the takeoff or approach condition.

Longitudinal Aerodynamic Characteristics and Wing Pressure Distributions of a Blended-Wing-Body Configuration at Low and High Reynolds Numbers

NASA Technical Reports Server (NTRS)

Re, Richard J.

2005-01-01

Force balance and wing pressure data were obtained on a 0.017-Scale Model of a blended-wing-body configuration (without a simulated propulsion system installation) to validate the capability of computational fluid dynamic codes to predict the performance of such thick sectioned subsonic transport configurations. The tests were conducted in the National Transonic Facility of the Langley Research Center at Reynolds numbers from 3.5 to 25.0 million at Mach numbers from 0.25 to 0.86. Data were obtained in the pitch plane only at angles of attack from -1 to 8 deg at Mach numbers greater than 0.25. A configuration with winglets was tested at a Reynolds number of 25.0 million at Mach numbers from 0.83 to 0.86.

NASA Hybrid Wing Aircraft Aeroacoustic Test Documentation Report

NASA Technical Reports Server (NTRS)

Heath, Stephanie L.; Brooks, Thomas F.; Hutcheson, Florence V.; Doty, Michael J.; Bahr, Christopher J.; Hoad, Danny; Becker, Lawrence; Humphreys, William M.; Burley, Casey L.; Stead, Dan;

Arrow-wing supersonic cruise aircraft structural design concepts evaluation. Volume 4: Sections 15 through 21

NASA Technical Reports Server (NTRS)

Sakata, I. F.; Davis, G. W.

1975-01-01

The analyses performed to provide structural mass estimates for the arrow wing supersonic cruise aircraft are presented. To realize the full potential for structural mass reduction, a spectrum of approaches for the wing and fuselage primary structure design were investigated. The objective was: (1) to assess the relative merits of various structural arrangements, concepts, and materials; (2) to select the structural approach best suited for the Mach 2.7 environment; and (3) to provide construction details and structural mass estimates based on in-depth structural design studies. Production costs, propulsion-airframe integration, and advanced technology assessment are included.

Analysis of 2-spar cantilever wings with special reference to torsion and load transference

NASA Technical Reports Server (NTRS)

Kuhn, Paul

1936-01-01

This report deals with the analysis of 2-spar cantilever wings in torsion, taking cognizance of the fact that the spars are not independent, but are interconnected by ribs and other structural members. The principles of interaction are briefly explained, showing that the mutual relief action occurring depends on the "pure torsional stiffness" of the wing cross section. Various practical methods of analysis are outlined. The "Friedrichs-Von Karman equations" are shown to require the least amount of labor. Numerical examples by the several methods of analysis are given and the agreement between the calculation and experiment is shown.

Exploratory investigation of the aerodynamic characteristics of a biwing vehicle at Mach 20.3

NASA Technical Reports Server (NTRS)

Bernot, P. T.

1984-01-01

Longitudinal and lateral-directional characteristics of a simple biwing configuration were determined over an angle-of-attack range from -3 deg to 50 deg. The body was comprised of a cylindrical section with an ogival forebody having an overall fineness ratio of 6.67. The delta wings had a 38.3 deg sweep angle and were geometrically similar in planform. The upper wing was located slightly forward relative to the lower wing. The model was tested in upright and inverted orientations including component buildups. This investigation was conducted in the 22-inch aerodynamics leg of the Langley Hypersonic Helium Tunnel Facility.

Investigation of a free-tip rotor configuration for research on spanwise life distributions and wake velocity surveys of a semi-span wing with a discontinuous twist

NASA Technical Reports Server (NTRS)

Fortin, Paul; Kumagai, Hiroyuki

1989-01-01

A wind tunnel test was conducted in the NASA Ames 7 x 10 Foot Wind Tunnel to investigate the lift distribution on a semi-span wing with a discontinuous change in spanwise twist. The semi-span wing had a tip with an adjustable pitch angle independent on the inboard section pitch angle simulating the free-tip rotor blade when its free-tip is at a deflected position. The spanwise lift distribution over the wing and the tip were measured and three component velocity surveys behind the wing were obtained with a three dimensional laser Doppler velocimeter (LV) with the wing at one angle of attack and the tip deflected at different pitch angles. A six component internal strain gage balance was also used to measure total forces and moments on the tip. The three dimensional lift was computed from the two dimensional life distributions obtained from the LV and from the strain gage balance. The results from both experimental methods are shown to be in agreement with predictions made by a steady, three dimensional panel code, VSAERO.

How Simple Is Reading in Arabic? A Cross-Sectional Investigation of Reading Comprehension from First to Sixth Grade

ERIC Educational Resources Information Center

Asadi, Ibrahim A.; Khateb, Asaid; Shany, Michal

2017-01-01

This study aimed to examine, from a cross-sectional perspective, the extent to which the simple view of reading (SVR) model can be adapted to the Arabic language. This was carried out by verifying, in both beginning and more skilled readers, whether the unique orthographical and morphological characteristics of Arabic contribute to reading…

Medical students’ personal choice for mode of delivery in Santa Catarina, Brazil: a cross-sectional, quantitative study

PubMed Central

2012-01-01

Background The increase in overall rates of cesarean sections (CS) in Brazil causes concern and it appears that multiple factors are involved in this fact. In 2009, undergraduate students in the first and final years of medical school at the University of Santa Catarina answered questionnaires regarding their choice of mode of delivery. The aim of the study was to evaluate whether the education process affects decision-making regarding the waay of childbirth preferred by medical students. Methods A cross-sectional, quantitative study was conducted based on data obtained from questionnaires applied to medical students. The questions addressed four different scenarios in childbirth, as follows: under an uneventful pregnancy; the mode of delivery for a pregnant woman under their care; the best choice as a healthcare manager and lastly, choosing the birth of their own child. For each circumstance, there was an open question to explain their choice. Results A total of 189 students answered the questionnaires. For any uneventful pregnancy and for a pregnant woman under their care, 8.46% of the students would opt for CS. As a healthcare manager, only 2.64% of the students would recommend CS. For these three scenarios, the answers of the students in the first year did not differ from those given by students in the sixth year. In the case of the student’s own or a partner’s pregnancy, 41.4% of those in the sixth year and 16.8% of those in the first year would choose a CS. A positive association was found between being a sixth year student and a personal preference for CS according to logistic regression (OR = 2.91; 95%CI: 1.03–8.30). Pain associated with vaginal delivery was usually the reason for choosing a CS. Conclusions A higher number of sixth year students preferred a CS for their own pregnancy (or their partner’s) compared to first year students. Pain associated with vaginal delivery was the most common reason given for haven chosen a CS. The students’ preference for childbirth changed over time during their graduation in favor of cesarean sections. This finding deserves considerable attention when structuring medical education in Obstetrics. PMID:22818043

Computational Optimization of a Natural Laminar Flow Experimental Wing Glove

NASA Technical Reports Server (NTRS)

Hartshom, Fletcher

2012-01-01

Computational optimization of a natural laminar flow experimental wing glove that is mounted on a business jet is presented and discussed. The process of designing a laminar flow wing glove starts with creating a two-dimensional optimized airfoil and then lofting it into a three-dimensional wing glove section. The airfoil design process does not consider the three dimensional flow effects such as cross flow due wing sweep as well as engine and body interference. Therefore, once an initial glove geometry is created from the airfoil, the three dimensional wing glove has to be optimized to ensure that the desired extent of laminar flow is maintained over the entire glove. TRANAIR, a non-linear full potential solver with a coupled boundary layer code was used as the main tool in the design and optimization process of the three-dimensional glove shape. The optimization process uses the Class-Shape-Transformation method to perturb the geometry with geometric constraints that allow for a 2-in clearance from the main wing. The three-dimensional glove shape was optimized with the objective of having a spanwise uniform pressure distribution that matches the optimized two-dimensional pressure distribution as closely as possible. Results show that with the appropriate inputs, the optimizer is able to match the two dimensional pressure distributions practically across the entire span of the wing glove. This allows for the experiment to have a much higher probability of having a large extent of natural laminar flow in flight.

Concept for a large multi-mission amphibian aircraft

NASA Technical Reports Server (NTRS)

Vaughan, J. C., III; Earl, T. D.

1979-01-01

A very large aircraft has been proposed for meeting both civil cargo and military transport needs for 1995 and beyond. The concept includes a wide noncircular fuselage cross section with a low wing, thick inner wing section, fuselage-mounted engines, and an air cushion landing gear. The civil freighter operates independently of congested passenger airports, using sheltered water as a runway and a waterfront land site for parking and ground operations. The military transport can operate from a wide variety of surfaces and temporary bases. The air cushion landing gear weighs substantially less than conventional gear and permits the use of extended takeoff distance resulting in improved payload/gross weight ratio.

The COREL and W12SC3 computer programs for supersonic wing design and analysis

NASA Technical Reports Server (NTRS)

Mason, W. H.; Rosen, B. S.

1983-01-01

Two computer codes useful in the supersonic aerodynamic design of wings, including the supersonic maneuver case are described. The nonlinear full potential equation COREL code performs an analysis of a spanwise section of the wing in the crossflow plane by assuming conical flow over the section. A subsequent approximate correction to the solution can be made in order to account for nonconical effects. In COREL, the flow-field is assumed to be irrotional (Mach numbers normal to shock waves less than about 1.3) and the full potential equation is solved to obtain detailed results for the leading edge expansion, supercritical crossflow, and any crossflow shockwaves. W12SC3 is a linear theory panel method which combines and extends elements of several of Woodward's codes, with emphasis on fighter applications. After a brief review of the aerodynamic theory used by each method, the use of the codes is illustrated with several examples, detailed input instructions and a sample case.

Damage Arresting Composites

NASA Technical Reports Server (NTRS)

Jegley, Dawn C.; Davis, Pamela A.

2015-01-01

Under NASA's Environmentally Responsible Aviation Project (ERA) the most promising vehicle concepts and technologies that can simultaneously reduce aircraft fuel use, community noise, and emissions are being evaluated. Two key factors to accomplishing these goals are reducing structural weight and moving away from the traditional tube and wing aircraft configuration to a shape that has improved lift and less drag. The hybrid wing body (HWB) configuration produces more lift and less drag by smoothly joining the wings to the center fuselage section so it provides aerodynamic advantages. This shape, however, presents structural challenges with its pressurized, non-circular cabin subjected to aerodynamic flight loads. In the HWB, the structure of the center section where the passenger cabin would be located must support large in-plane loads as well as internal pressure on nearly-flat panels and right-angle joints. This structural arrangement does not lend itself to simple, efficient designs. Traditional aluminum and even state-of-the-art composites do not provide a solution to this challenge.

Effects of spanwise blowing on the pressure field and vortex-lift characteristics of a 44 deg swept trapezoidal wing. [wind tunnel stability tests - aircraft models

NASA Technical Reports Server (NTRS)

Campbell, J. F.

1975-01-01

Wind-tunnel data were obtained at a free-stream Mach number of 0.26 for a range of model angle of attack, jet thrust coefficient, and jet location. Results of this study show that the sectional effects to spanwise blowing are strongly dependent on angle of attack, jet thrust coefficient, and span location; the largest effects occur at the highest angles of attack and thrust coefficients and on the inboard portion of the wing. Full vortex lift was achieved at the inboard span station with a small blowing rate, but successively higher blowing rates were necessary to achieve full vortex lift at increased span distances. It is shown that spanwise blowing increases lift throughout the angle-of-attack range, delays wing stall to higher angles of attack, and improves the induced-drag polars. The leading-edge suction analogy can be used to estimate the section and total lifts resulting from spanwise blowing.

Pressure-Distribution Measurements of a Model of a Davis Wing Section with Fowler Flap Submitted by Consolidated Aircraft Corporation

NASA Technical Reports Server (NTRS)

Abbott, Ira H

1942-01-01

Wing pressure distribution diagrams for several angles of attack and flap deflections of 0 degrees, 20 degrees, and 40 degrees are presented. The normal force coefficients agree with lift coefficients obtained in previous test of the same model, except for the maximum lifts with flap deflection. Pressure distribution measurements were made at Reynolds Number of about 6,000,000.

48. Photograph of an original construction drawing, dated August 1927, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

48. Photograph of an original construction drawing, dated August 1927, in the possession of Facilities Planning Office, Iowa State University, Ames, Iowa. ELEVATIONS CROSS SECTIONS THROUGH COURTYARD SHOWING EAST ELEVATION OF FRONT (WEST) PORTION OF BUILDING, SOUTH ELEVATION OF NORTH WING, NORTH ELEVATION OF SOUTH WING, PLOT PLAN, AND DETAILS; SHEET NO. 6 OF 10 - Dairy Industry Building, Iowa State University campus, Ames, Story County, IA

Aerodynamics of a finite wing with simulated ice

NASA Technical Reports Server (NTRS)

Bragg, M. B.; Khodadoust, A.; Kerho, M.

1992-01-01

The effect of a simulated glaze ice accretion on the aerodynamic performance of a three-dimensional wing is studied experimentally. Results are reviewed from earlier two-dimensional tests which show the character of the large leading-edge separation bubbles caused by the simulated ice accretion. The 2-D bubbles are found to closely resemble well known airfoil laminar separation bubbles. For the 3-D experiments a semispan wing of effective aspect ratio five was mounted from the sidewall of the UIUC subsonic wind tunnel. The model uses a NACA 0012 airfoil section on a rectangular planform with interchangeable tip and root sections to allow for 0- and 30-degree sweep. A three-component sidewall balance was used to measure lift, drag and pitching moment on the clean and iced model. Fluorescent oil flow visualization has been performed on the iced model and reveals extensive spanwise and vortical flow in the separation bubble aft of the upper surface horn. Sidewall interaction and spanwise nonuniformity are also seen on the unswept model. Comparisons to the computed flow fields are shown. Results are also shown for roughness effects on the straight wing. Sand grain roughness on the ice shape is seen to have a different effect than isolated 3-D roughness elements.

Analysis of a Hybrid Wing Body Center Section Test Article

NASA Technical Reports Server (NTRS)

Wu, Hsi-Yung T.; Shaw, Peter; Przekop, Adam

2013-01-01

The hybrid wing body center section test article is an all-composite structure made of crown, floor, keel, bulkhead, and rib panels utilizing the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) design concept. The primary goal of this test article is to prove that PRSEUS components are capable of carrying combined loads that are representative of a hybrid wing body pressure cabin design regime. This paper summarizes the analytical approach, analysis results, and failure predictions of the test article. A global finite element model of composite panels, metallic fittings, mechanical fasteners, and the Combined Loads Test System (COLTS) test fixture was used to conduct linear structural strength and stability analyses to validate the specimen under the most critical combination of bending and pressure loading conditions found in the hybrid wing body pressure cabin. Local detail analyses were also performed at locations with high stress concentrations, at Tee-cap noodle interfaces with surrounding laminates, and at fastener locations with high bearing/bypass loads. Failure predictions for different composite and metallic failure modes were made, and nonlinear analyses were also performed to study the structural response of the test article under combined bending and pressure loading. This large-scale specimen test will be conducted at the COLTS facility at the NASA Langley Research Center.

Applications of a direct/iterative design method to complex transonic configurations

NASA Technical Reports Server (NTRS)

Smith, Leigh Ann; Campbell, Richard L.

1992-01-01

The current study explores the use of an automated direct/iterative design method for the reduction of drag in transport configurations, including configurations with engine nacelles. The method requires the user to choose a proper target-pressure distribution and then develops a corresponding airfoil section. The method can be applied to two-dimensional airfoil sections or to three-dimensional wings. The three cases that are presented show successful application of the method for reducing drag from various sources. The first two cases demonstrate the use of the method to reduce induced drag by designing to an elliptic span-load distribution and to reduce wave drag by decreasing the shock strength for a given lift. In the second case, a body-mounted nacelle is added and the method is successfully used to eliminate increases in wing drag associated with the nacelle addition by designing to an arbitrary pressure distribution as a result of the redesigning of a wing in combination with a given underwing nacelle to clean-wing, target-pressure distributions. These cases illustrate several possible uses of the method for reducing different types of drag. The magnitude of the obtainable drag reduction varies with the constraints of the problem and the configuration to be modified.

Wing design for a civil tiltrotor transport aircraft

NASA Technical Reports Server (NTRS)

Rais-Rohani, Masoud

1994-01-01

The goal of this research is the proper tailoring of the civil tiltrotor's composite wing-box structure leading to a minimum-weight wing design. With focus on the structural design, the wing's aerodynamic shape and the rotor-pylon system are held fixed. The initial design requirement on drag reduction set the airfoil maximum thickness-to-chord ratio to 18 percent. The airfoil section is the scaled down version of the 23 percent-thick airfoil used in V-22's wing. With the project goal in mind, the research activities began with an investigation of the structural dynamic and aeroelastic characteristics of the tiltrotor configuration, and the identification of proper procedures to analyze and account for these characteristics in the wing design. This investigation led to a collection of more than thirty technical papers on the subject, some of which have been referenced here. The review of literature on the tiltrotor revealed the complexity of the system in terms of wing-rotor-pylon interactions. The aeroelastic instability or whirl flutter stemming from wing-rotor-pylon interactions is found to be the most critical mode of instability demanding careful consideration in the preliminary wing design. The placement of wing fundamental natural frequencies in bending and torsion relative to each other and relative to the rotor 1/rev frequencies is found to have a strong influence on the whirl flutter. The frequency placement guide based on a Bell Helicopter Textron study is used in the formulation of frequency constraints. The analysis and design studies are based on two different finite-element computer codes: (1) MSC/NASATRAN and (2) WIDOWAC. These programs are used in parallel with the motivation to eventually, upon necessary modifications and validation, use the simpler WIDOWAC code in the structural tailoring of the tiltrotor wing. Several test cases were studied for the preliminary comparison of the two codes. The results obtained so far indicate a good overall agreement between the two codes.

An interactive user-friendly approach to surface-fitting three-dimensional geometries

NASA Technical Reports Server (NTRS)

Cheatwood, F. Mcneil; Dejarnette, Fred R.

1988-01-01

A surface-fitting technique has been developed which addresses two problems with existing geometry packages: computer storage requirements and the time required of the user for the initial setup of the geometry model. Coordinates of cross sections are fit using segments of general conic sections. The next step is to blend the cross-sectional curve-fits in the longitudinal direction using general conics to fit specific meridional half-planes. Provisions are made to allow the fitting of fuselages and wings so that entire wing-body combinations may be modeled. This report includes the development of the technique along with a User's Guide for the various menus within the program. Results for the modeling of the Space Shuttle and a proposed Aeroassist Flight Experiment geometry are presented.

12. NORTH WALL, SOUTH SIDE, EAST SECTION (WEST SIDE OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. NORTH WALL, SOUTH SIDE, EAST SECTION (WEST SIDE OF EAST WING IN BACKGROUND) - Fort Sam Houston, San Antonio Quartermaster Depot, Northwest corner of New Braunfels Avenue & Grayson Street, San Antonio, Bexar County, TX

40 CFR 60.4 - Address.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Environmental Protection Agency, 1200 Sixth Avenue, Seattle, WA 98101. (b) Section 111(c) directs the..., Division of Air Pollution Control, Arkansas Department of Pollution Control and Ecology, 8001 National... Park Avenue, Victorville, CA 92392-2310. Monterey Bay Unified Air Pollution Control District, 24580...

Three-dimensional flow structures and evolution of the leading-edge vortices on a flapping wing.

PubMed

Lu, Yuan; Shen, Gong Xin

2008-04-01

Following the identification and confirmation of the substructures of the leading-edge vortex (LEV) system on flapping wings, it is apparent that the actual LEV structures could be more complex than had been estimated in previous investigations. In this experimental study, we reveal for the first time the detailed three-dimensional (3-D) flow structures and evolution of the LEVs on a flapping wing in the hovering condition at high Reynolds number (Re=1624). This was accomplished by utilizing an electromechanical model dragonfly wing flapping in a water tank (mid-stroke angle of attack=60 degrees) and applying phase-lock based multi-slice digital stereoscopic particle image velocimetry (DSPIV) to measure the target flow fields at three typical stroke phases: at 0.125 T (T=stroke period), when the wing was accelerating; at 0.25 T, when the wing had maximum speed; and at 0.375 T, when the wing was decelerating. The result shows that the LEV system is a collection of four vortical elements: one primary vortex and three minor vortices, instead of a single conical or tube-like vortex as reported or hypothesized in previous studies. These vortical elements are highly time-dependent in structure and show distinct ;stay properties' at different spanwise sections. The spanwise flows are also time-dependent, not only in the velocity magnitude but also in direction.

Viper cabin-fuselage structural design concept with engine installation and wing structural design

NASA Technical Reports Server (NTRS)

Marchesseault, B.; Carr, D.; Mccorkle, T.; Stevens, C.; Turner, D.

1993-01-01

This report describes the process and considerations in designing the cabin, nose, drive shaft, and wing assemblies for the 'Viper' concept aircraft. Interfaces of these assemblies, as well as interfaces with the sections of the aircraft aft of the cabin, are also discussed. The results of the design process are included. The goal of this project is to provide a structural design which complies with FAR 23 requirements regarding occupant safety, emergency landing loads, and maneuvering loads. The design must also address the interfaces of the various systems in the cabin, nose, and wing, including the drive shaft, venting, vacuum, electrical, fuel, and control systems. Interfaces between the cabin assembly and the wing carrythrough and empennage assemblies were required, as well. In the design of the wing assemblies, consistency with the existing cabin design was required. The major areas considered in this report are materials and construction, loading, maintenance, environmental considerations, wing assembly fatigue, and weight. The first three areas are developed separately for the nose, cabin, drive shaft, and wing assemblies, while the last three are discussed for the entire design. For each assembly, loading calculations were performed to determine the proper sizing of major load carrying components. Table 1.0 lists the resulting margins of safety for these key components, along with the types of the loads involved, and the page number upon which they are discussed.

Design development of graphite primary structures enables SSTO success

NASA Astrophysics Data System (ADS)

Biagiotti, V. A.; Yahiro, J. S.; Suh, Daniel E.; Hodges, Eric R.; Prior, Donald J.

1997-01-01

This paper describes the development of a graphite composite wing and a graphite composite intertank primary structure for application toward Single-Stage to Orbit space vehicles such as those under development in NASA's X-33/Reusable Launch Vehicle (RLV) Program. The trade study and designs are based on a Rockwell vertical take-off and horizontal landing (VTHL) wing-body RLV vehicle. Northrop Grumman's approach using a building block development technique is described. Composite Graphite/Bismaleimide (Gr/BMI) material characterization test results are presented. Unique intertank and wing composite subcomponent test article designs are described and test results to date are presented. Wing and intertank Full Scale Section Test Article (FSTA) objectives and designs are outlined. Trade studies, supporting building block testing, and FSTA demonstrations combine to develop graphite primary structure composite technology that enables developing X-33/RLV design programs to meet critical SSTO structural weight and operations performance criteria.

Advanced recovery systems wind tunnel test report

NASA Technical Reports Server (NTRS)

Geiger, R. H.; Wailes, W. K.

1990-01-01

Pioneer Aerospace Corporation (PAC) conducted parafoil wind tunnel testing in the NASA-Ames 80 by 120 test sections of the National Full-Scale Aerodynamic Complex, Moffett Field, CA. The investigation was conducted to determine the aerodynamic characteristics of two scale ram air wings in support of air drop testing and full scale development of Advanced Recovery Systems for the Next Generation Space Transportation System. Two models were tested during this investigation. Both the primary test article, a 1/9 geometric scale model with wing area of 1200 square feet and secondary test article, a 1/36 geometric scale model with wing area of 300 square feet, had an aspect ratio of 3. The test results show that both models were statically stable about a model reference point at angles of attack from 2 to 10 degrees. The maximum lift-drag ratio varied between 2.9 and 2.4 for increasing wing loading.

Subsonic panel method for designing wing surfaces from pressure distribution

NASA Technical Reports Server (NTRS)

Bristow, D. R.; Hawk, J. D.

1983-01-01

An iterative method has been developed for designing wing section contours corresponding to a prescribed subcritical distribution of pressure. The calculations are initialized by using a surface panel method to analyze a baseline wing or wing-fuselage configuration. A first-order expansion to the baseline panel method equations is then used to calculate a matrix containing the partial derivative of potential at each control point with respect to each unknown geometry parameter. In every iteration cycle, the matrix is used both to calculate the geometry perturbation and to analyze the perturbed geometry. The distribution of potential on the perturbed geometry is established by simple linear extrapolation from the baseline solution. The extrapolated potential is converted to pressure by Bernoulli's equation. Not only is the accuracy of the approach good for very large perturbations, but the computing cost of each complete iteration cycle is substantially less than one analysis solution by a conventional panel method.

Temperature Distribution Measurement of The Wing Surface under Icing Conditions

NASA Astrophysics Data System (ADS)

Isokawa, Hiroshi; Miyazaki, Takeshi; Kimura, Shigeo; Sakaue, Hirotaka; Morita, Katsuaki; Japan Aerospace Exploration Agency Collaboration; Univ of Notre Dame Collaboration; Kanagawa Institute of Technology Collaboration; Univ of Electro-(UEC) Team, Comm

2016-11-01

De- or anti-icing system of an aircraft is necessary for a safe flight operation. Icing is a phenomenon which is caused by a collision of supercooled water frozen to an object. For the in-flight icing, it may cause a change in the wing cross section that causes stall, and in the worst case, the aircraft would fall. Therefore it is important to know the surface temperature of the wing for de- or anti-icing system. In aerospace field, temperature-sensitive paint (TSP) has been widely used for obtaining the surface temperature distribution on a testing article. The luminescent image from the TSP can be related to the temperature distribution. (TSP measurement system) In icing wind tunnel, we measured the surface temperature distribution of the wing model using the TSP measurement system. The effect of icing conditions on the TSP measurement system is discussed.

Emergency Victim Care. A Training Manual for Emergency Medical Technicians. Module 6. Bleeding Control, Wounds and Bandaging, Shock. Revised.

ERIC Educational Resources Information Center

Ohio State Dept. of Education, Columbus. Div. of Vocational Education.

This student manual, the sixth in a set of 14 modules, is designed to train emergency medical technicians (EMTs) in Ohio. The module contains three sections covering the following course content: control of bleeding, caring for wounds and bandaging various body parts, and caring for shock victims. Each section contains objectives, an introduction,…

How Do Different Cognitive and Linguistic Variables Contribute to Reading in Arabic? A Cross-Sectional Study from First to Sixth Grade

ERIC Educational Resources Information Center

Asadi, Ibrahim A.; Khateb, Asaid; Ibrahim, Raphiq; Taha, Haitham

2017-01-01

The contribution of linguistic and cognitive variables to reading processes might vary depending on the particularities of the languages studied. This view is thought to be particularly true for Arabic which is a diglossic language and has particular orthographic and morpho-syntactic systems. This cross-sectional study examined the contribution of…

Flight survey of the 757 wing noise field and its effects on laminar boundary layer transition. Volume 1: Program description and data analysis

NASA Technical Reports Server (NTRS)

1987-01-01

It was previously observed that an incident acoustic field on a wing with laminar flow can cause transition to turbulent flow if the fluctuating acoustic velocities are of sufficient amplitude and in the critical frequency range for an unstable laminar boundary layer. A section of a wing was modified with a natural laminar flow (NLF) glove to allow direct measurement of the effect of varying engine noise on the extent of laminar flow. The flight test program was completed in June, 1985. At each flight condition, the engine power was varied from about 2600 r/min (idle) to about 4500 r/min (maximum continuous power). The spectral data provides considerable insight into the influences of the various sound sources that contribute to the overall noise levels. Additional analysis will be required to assess the impact of these sources on boundary layer transition. These results demonstrate that substantial laminar flow on the wing of a transport configuration with wing-mounted engines can be obtained.

Spinning characteristics of wings II : rectangular Clark Y biplane cellule: 25 percent stagger; 0 degree decalage; gap/chord 1.0

NASA Technical Reports Server (NTRS)

Bamber, M J

1935-01-01

General methods of theoretical analysis of airplane spinning characteristics have been available for some time. Some of these methods of analysis might be used by designers to predict the spinning characteristics of proposed airplane designs if the necessary aerodynamic data were known. The present investigation, to determine the spinning characteristics of wings, is planned to include variations in airfoil sections, plan forms, and tip shapes of monoplane wings and variations in stagger, gap, and decalage for biplane cellules. The first series of tests, made on a rectangular Clark Y monoplane wing, are reported in reference 1. That report also gives an analysis of the data for predicting the probable effects of various important parameters on the spin for normal airplanes using such a wing. The present report is the second of the series. It gives the aerodynamic characteristics of a rectangular Clark Y biplane cellule in spinning attitudes and includes a discussion of the data, using the method of analysis given in reference 1.

Preliminary noise tests of the engine-over-the-wing concept. 2: 10 deg - 20 deg flap position

NASA Technical Reports Server (NTRS)

Reshotko, M.; Olsen, W. A.; Dorsch, R. G.

1972-01-01

Preliminary acoustic tests of the engine-over-the-wing concept as a method for reducing the aerodynamic noise created by conventional and short takeoff aircraft are discussed. Tests were conducted with a small wing section model having two flaps which can be set for either the landing or takeoff positions. Data was acquired with the flaps set at 10 degrees and 20 degrees for takeoff and 30 and 60 degrees for landing. The engine exhaust was simulated by an air jet from a convergent nozzle. Far field noise data are presented for nominal pressure ratios of 1.25, 1.4 and 1.7 for both the flyover and sideline modes.

Supersonic full-potential methods for missile body analysis

NASA Technical Reports Server (NTRS)

Pittman, James L.

1992-01-01

Accounts are presented of representative applications to missile bodies of arbitrary shape of methods based on the steady form of the full potential equation. The NCOREL and SIMP full-potential codes are compared, and their results are evaluated for the cases of an arrow wing and a wing-body configuration. Attention is given to the effect of cross-sectional and longitudinal geometries. Comparisons of surface pressure and longitudinal force and moment data for circular and elliptic bodies have shown that the full-potential methods yielded excellent results in attached-flow conditions. Results are presented for a conical star body, waveriders, the Shuttle Orbiter, and a highly swept wing-body cruising at Mach 4.

Thin tailored composite wing for civil tiltrotor

NASA Technical Reports Server (NTRS)

Rais-Rohani, Masoud

1994-01-01

The tiltrotor aircraft is a flight vehicle which combines the efficient low speed (i.e., take-off, landing, and hover) characteristics of a helicopter with the efficient cruise speed of a turboprop airplane. A well-known example of such vehicle is the Bell-Boeing V-22 Osprey. The high cruise speed and range constraints placed on the civil tiltrotor require a relatively thin wing to increase the drag-divergence Mach number which translates into lower compressibility drag. It is required to reduce the wing maximum thickness-to-chord ratio t/c from 23% (i.e., V-22 wing) to 18%. While a reduction in wing thickness results in improved aerodynamic efficiency, it has an adverse effect on the wing structure and it tends to reduce structural stiffness. If ignored, the reduction in wing stiffness leads to susceptibility to aeroelastic and dynamic instabilities which may consequently cause a catastrophic failure. By taking advantage of the directional stiffness characteristics of composite materials the wing structure may be tailored to have the necessary stiffness, at a lower thickness, while keeping the weight low. The goal of this study is to design a wing structure for minimum weight subject to structural, dynamic and aeroelastic constraints. The structural constraints are in terms of strength and buckling allowables. The dynamic constraints are in terms of wing natural frequencies in vertical and horizontal bending and torsion. The aeroelastic constraints are in terms of frequency placement of the wing structure relative to those of the rotor system. The wing-rotor-pylon aeroelastic and dynamic interactions are limited in this design study by holding the cruise speed, rotor-pylon system, and wing geometric attributes fixed. To assure that the wing-rotor stability margins are maintained a more rigorous analysis based on a detailed model of the rotor system will need to ensue following the design study. The skin-stringer-rib type architecture is used for the wing-box structure. The design variables include upper and lower skin ply thicknesses and orientation angles, spar and rib web thicknesses and cap areas, and stringer cross-sectional areas. These design variables will allow the maximum tailoring of the structure to meet the design requirements most efficiently. Initial dynamic analysis has been conducted using MSC/NASTRAN to determine the baseline wing's frequencies and mode shapes. For the design study we intend to use the finite-element based code called WIDOWAC (Wing Design Optimization With Aeroeastic Constraints) that was developed at NASA Langley in early 1970's for airplane wing structural analysis and preliminary design. Currently, the focus is on modification and validation of this code which will be used for the civil tiltrotor design efforts.

Social Studies. [SITE 2002 Section].

ERIC Educational Resources Information Center

2002

This document contains the following papers on social studies from the SITE (Society for Information Technology & Teacher Education) 2002 conference: (1) "Technology Portfolios in Pre-Service Social Studies Teacher Education" (Marsha Alibrandi); (2) "North Carolina's Sixth Graders Go to Russia: A Global Education/Curriculum Integration Project…

40 CFR 61.04 - Address.

Code of Federal Regulations, 2012 CFR

2012-07-01

... of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION... Protection Agency, 1200 Sixth Avenue (OAQ-107), Seattle, WA 98101. (b) Section 112(d) of the Act directs the Administrator to delegate to each State, when appropriate, the authority to implement and enforce national...

The Aluminum Falcon: a Low Cost Modern Commercial Transport

NASA Technical Reports Server (NTRS)

Bryant, Mark; Hernandez, Estela; King, Gregory; Lor, Alex Choua; Musser, Jana; Trigs, Deanne; Yee, Susan

1994-01-01

The American Institute of Aeronautics and Astronautics (AIAA) released a Request For Proposal (RFP) in the form of an undergraduate design competition for a 153 passenger jet transport with a range of 3,000 nautical miles. The primary requirement for this aircraft was low cost, both in acquisition and operation, with a technology availability date of the year 2000. This report presents the Non-Solo Design Group's response to the RFP, the Aluminum Falcon (AF-1). Non-Solo's approach to development was to take the best elements of seven individual preliminary designs, then combine and refine them. The resulting aircraft meets or exceeds all requirements of both the RFP and the Federal Aviation Administration (FAA). Highlights include a revolutionary wing planform, known as an M-wing, which offers many advantages over a conventional aft swept wing. For example, the M-wing lessens the travel in the aircraft center of gravity caused by fuel being stored in the wing. It also reduces the amount of torque imposed on the center wing box because more of the lifting load acts near the fuselage joint, rather than behind it. In essence, the M-wing offers the best of both worlds: using a forward swept wing root places the aerodynamic center of the wing further forward and allows the landing gear to be placed without the use of a yahudi. At the same time, with the outboard section swept backward the tip retains an amount of aeroelastic dampening that is lost on a completely forward swept wing. The result is a wing which has many advantages of a straight, unswept wings without the severe compressibility effects at high Mach numbers. Other highlights include judicious use of composites, giving recognition to the importance of weight and its effect on aircraft cost and performance, and an advanced passenger entertainment system which can be used as a source of revenue for the airlines. This aircraft meets the low-cost doctrine with an acquisition cost of $29 million and a direct operating cost of 3.5 cents per seat mile. The AF-1 incorporates new ideas with existing technology to result in an aircraft that will retain market viability well into the next century.

Vortex Flow Correlation

DTIC Science & Technology

1981-01-01

vorticity model used on the wing as well as on the leading-edge vortex sheet. Since the trailing-edge wake vorti- city does not have the close...z SECTION B-B ( WAKE ) FIGURE 11. FLOW PAST A SLENDER WING WITH LEADING-EDGE VORTEX FLOW 49 * -- A water tunnel is useful in visualizing the reversed...on fighter aircraft which generate strong vortical flows. The differences in apparent mass between a model in air and a model in water require analysis

Aerodynamic Analysis of a Hale Aircraft Joined-Wing Configuration

NASA Astrophysics Data System (ADS)

Sivaji, Rangarajan; Ghia, Urmila; Ghia, Karman; Thornburg, Hugh

2003-11-01

Aerodynamic analysis of a high-aspect ratio, joined wing of a High-Altitude Long Endurance (HALE) aircraft is performed. The requirement of high lift over extended flight periods for the HALE aircraft leads to high-aspect ratio wings experiencing significant deflections necessitating consideration of aeroelastic effects. The finite-volume solver COBALT, with Reynolds-averaged Navier-Stokes (RANS) and Detached Eddy Simulation (DES) capabilities, is used for the flow simulations. Calculations are performed at á = 0° and 12° for M = 0.6, at an altitude of 30,000 feet, at a Re per unit length of 5.6x106. The wing cross sections are NACA 4421 airfoils. Because of the high lift-to-drag ratio wings, an inviscid flow analysis is also performed. The inviscid surface pressure coefficient (Cp) is compared with the corresponding viscous Cp to examine the feasibility of the use of the inviscid pressure loads as an estimate of the total fluid loads on the structure. The viscous and inviscid Cp results compare reasonably only at á = 0°. The viscous flow is examined in detail via surface and field velocity vectors, vorticity, density and pressure contours. For á = 12°, the unsteady DES solutions show a weak shock at the aft-wing trailing edge. Also, the flow near the joint exhibits a region of mild separation.

Simulations of dynamics of plunge and pitch of a three-dimensional flexible wing in a low Reynolds number flow

NASA Astrophysics Data System (ADS)

Qi, Dewei; Liu, Yingming; Shyy, Wei; Aono, Hikaru

2010-09-01

The lattice Boltzmann flexible particle method (LBFPM) is used to simulate fluid-structure interaction and motion of a flexible wing in a three-dimensional space. In the method, a beam with rectangular cross section has been discretized into a chain of rigid segments. The segments are connected through ball and socket joints at their ends and may be bent and twisted. Deformation of flexible structure is treated with a linear elasticity model through bending and twisting. It is demonstrated that the flexible particle method (FPM) can approximate the nonlinear Euler-Bernoulli beam equation without resorting to a nonlinear elasticity model. Simulations of plunge and pitch of flexible wing at Reynolds number Re=136 are conducted in hovering condition by using the LBFPM. It is found that both lift and drag forces increase first, then decrease dramatically as the bending rigidity in spanwise direction decreases and that the lift and drag forces are sensitive to rigidity in a certain range. It is shown that the downwash flows induced by wing tip and trailing vortices in wake area are larger for a flexible wing than for a rigid wing, lead to a smaller effective angle of attack, and result in a larger lift force.

Finite Element Analysis and Test Results Comparison for the Hybrid Wing Body Center Section Test Article

NASA Technical Reports Server (NTRS)

Przekop, Adam; Jegley, Dawn C.; Rouse, Marshall; Lovejoy, Andrew E.

2016-01-01

This report documents the comparison of test measurements and predictive finite element analysis results for a hybrid wing body center section test article. The testing and analysis efforts were part of the Airframe Technology subproject within the NASA Environmentally Responsible Aviation project. Test results include full field displacement measurements obtained from digital image correlation systems and discrete strain measurements obtained using both unidirectional and rosette resistive gauges. Most significant results are presented for the critical five load cases exercised during the test. Final test to failure after inflicting severe damage to the test article is also documented. Overall, good comparison between predicted and actual behavior of the test article is found.

Reflection-plane tests of spoilers on an advanced technology wing with a large Fowler flap

NASA Technical Reports Server (NTRS)

Wentz, W. H., Jr.; Volk, C. G., Jr.

1976-01-01

Wind tunnel experiments were conducted to determine the effectiveness of spoilers applied to a finite-span wing which utilizes the GA(W)-1 airfoil section and a 30% chord full-span Fowler flap. A series of spoiler cross sectioned shapes were tested utilizing a reflection-plane model. Five-component force characteristics and hinge moment measurements were obtained. Results confirm earlier two-dimensional tests which showed that spoilers could provide large lift increments at any flap setting, and that spoiler control reversal tendencies could be eliminated by providing a vent path from lower surface to upper surface. Performance penalties due to spoiler leakage airflow were measured.

50 CFR 20.103 - Seasons, limits, and shooting hours for mourning and white-winged doves and wild pigeons.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY... the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and...

Small-Scale Transonic Investigation of the Effects of Partial-Span Leading-Edge Camber on the Aerodynamic Characteristics of a 50 Deg 38' Sweptback Wing of Aspect Ratio 2.98

NASA Technical Reports Server (NTRS)

Alford, William J., Jr.; Byrnes, Andrew L., Jr.

1952-01-01

A small-scale transonic investigation of two semispan wings of the same plan form was made in the Langley high-speed 7- by 10-foot tunnel through a Mach number range of 0.70 to 1.10 and a mean-test Reynolds number range of 745,000 to 845,000 to determine the effects of partial-span leading-edge camber on the aerodynamic characteristics of a swept-back wing. This paper presents the results of the investigation of wing-alone and wing-fuselage configurations of the two wings; one, was an uncambered wing and the other had the forward 45 percent of the chord cambered over the outboard 55 percent of the span. The semispan wings had 50deg 38ft sweepback of their quarter-chord lines, aspect ratio of 2.98, taper ratio of 0.45, and modified NACA 64A-series airfoil sections tapered in thickness ratio. Lift, drag, pitching moment, and root-bending moment were obtained for these configurations. The results indicated that, for the wing-alone configuration, use of the partial-span leading-edge camber provided an increase in maximum lift-drag ratios up to a Mach number of 0.95, after which no gain was realized. For the wing-fuselage combination, the partial-span leading-edge camber appeared to cause no gain in maximum lift-drag ratio throughout the test range of Mach numbers. The lift-curve slopes of the partial-span leading-edge camber configurations indicated no significant change over the basic configurations in the subsonic range but resulted in slight reductions at the higher Mach numbers. No significantly large changes in pitching-moment-curve slopes or lateral center of additional loading were indicated because of the modification.

A Matrix for Processing Descriptive and Judgmental Data for Use with the Learning Area Sections of the "Evaluative Criteria," Sixth Edition.

ERIC Educational Resources Information Center

Pace, Vernon D.; Buser, Robert L.

1990-01-01

Presents a matrix that can be used by accreditation team members to gather, organize, analyze, and report descriptive and evaluative information about instructional support components, teacher observations/interviews, and curriculum evaluation. (DMM)

36 CFR 228.102 - Leasing analyses and decisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... decisions. 228.102 Section 228.102 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE MINERALS Oil and Gas Resources Leasing § 228.102 Leasing analyses and decisions. (a) Compliance... further planning in Executive Communication 1504, Ninety-Sixth Congress (House Document No. 96-119...

A fundamental study of drag and an assessment of conventional drag-due-to-lift reduction devices

NASA Astrophysics Data System (ADS)

Yates, J. E.; Donald, C. D.

1986-09-01

The integral conservation laws of fluid mechanics are used to assess the drag efficiency of lifting wings, both CTOL and various out-of-plane configurations. The drag-due-to-lift is separated into two major components: (1) the induced drag-due-to-lift that depends on aspect ratio but is relatively independent of Reynolds number; (2) the form drag-due-to-lift that is independent of aspect ratio but dependent on the details of the wing section design, planform and Reynolds number. For each lifting configuration there is an optimal load distribution that yields the minimum value of drag-due-to-lift. For well designed high aspect ratio CTOL wings the two drag components are independent. With modern design technology CTOL wings can be (and usually are) designed with a drag-due-to-lift efficiency close to unity. Wing tip-devices (winglets, feathers, sails, etc.) can improve drag-due-to-lift efficiency by 10 to 15% if they are designed as an integral part of the wing. As add-on devices they can be detrimental. It is estimated that 25% improvements of wing drag-due-to-lift efficiency can be obtained with joined tip configurations and vertically separated lifting elements without considering additional benefits that might be realized by improved structural efficiency. It is strongly recommended that an integrated aerodynamic/structural approach be taken in the design of (or research on) future out-of-plane configurations.

A fundamental study of drag and an assessment of conventional drag-due-to-lift reduction devices

NASA Technical Reports Server (NTRS)

Yates, J. E.; Donald, C. D.

1986-01-01

The integral conservation laws of fluid mechanics are used to assess the drag efficiency of lifting wings, both CTOL and various out-of-plane configurations. The drag-due-to-lift is separated into two major components: (1) the induced drag-due-to-lift that depends on aspect ratio but is relatively independent of Reynolds number; (2) the form drag-due-to-lift that is independent of aspect ratio but dependent on the details of the wing section design, planform and Reynolds number. For each lifting configuration there is an optimal load distribution that yields the minimum value of drag-due-to-lift. For well designed high aspect ratio CTOL wings the two drag components are independent. With modern design technology CTOL wings can be (and usually are) designed with a drag-due-to-lift efficiency close to unity. Wing tip-devices (winglets, feathers, sails, etc.) can improve drag-due-to-lift efficiency by 10 to 15% if they are designed as an integral part of the wing. As add-on devices they can be detrimental. It is estimated that 25% improvements of wing drag-due-to-lift efficiency can be obtained with joined tip configurations and vertically separated lifting elements without considering additional benefits that might be realized by improved structural efficiency. It is strongly recommended that an integrated aerodynamic/structural approach be taken in the design of (or research on) future out-of-plane configurations.

KSC00pp1721

NASA Image and Video Library

2000-10-27

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility, STS-97 Mission Specialist Carlos Noriega checks out the mission payload, the P6 integrated truss segment, while Mission Specialist Joe Tanner looks on. Mission STS-97 is the sixth construction flight to the International Space Station. The P6 comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the International Space Station. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. The mission includes two spacewalks by Noriega and Tanner to complete the solar array connections. STS-97 is scheduled to launch Nov. 30 at about 10:06 p.m. EST

KSC-00pp1780

NASA Image and Video Library

2000-11-30

STS-97 Mission Specialist Marc Garneau, who is with the Canadian Space Agency, waves after donning his launch and entry suit. This is his third Shuttle flight.; Mission STS-97 is the sixth construction flight to the International Space Station. It is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the Space Station. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. The 11-day mission includes two spacewalks to complete the solar array connections. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity.. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. Launch is scheduled for Nov. 30 at 10:06 p.m. EST

KSC-00pp1781

NASA Image and Video Library

2000-11-30

With the help of a suit technician, STS-97 Commander Brent Jett dons his launch and entry suit. This is his third Shuttle flight.; Mission STS-97 is the sixth construction flight to the International Space Station. It is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the Space Station. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. The 11-day mission includes two spacewalks to complete the solar array connections. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. Launch is scheduled for Nov. 30 at 10:06 p.m. EST

KSC00pp1720

NASA Image and Video Library

2000-10-27

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility, STS-97 Mission Specialists Carlos Noriega (far left) and Joe Tanner (right) check out the mission payload, the P6 integrated truss segment. Mission STS-97 is the sixth construction flight to the International Space Station. The P6 comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the International Space Station. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. The mission includes two spacewalks by Noriega and Tanner to complete the solar array connections. STS-97 is scheduled to launch Nov. 30 at about 10:06 p.m. EST

KSC-00pp1783

NASA Image and Video Library

2000-11-30

STS-97 Mission Specialist Carlos Noriega appears relaxed as he dons his launch and entry suit. This is his second Shuttle flight. Mission STS-97 is the sixth construction flight to the International Space Station. It is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the Space Station. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. The 11-day mission includes two spacewalks to complete the solar array connections. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. Launch is scheduled for Nov. 30 at 10:06 p.m. EST

KSC-00pp1721

NASA Image and Video Library

2000-10-27

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility, STS-97 Mission Specialist Carlos Noriega checks out the mission payload, the P6 integrated truss segment, while Mission Specialist Joe Tanner looks on. Mission STS-97 is the sixth construction flight to the International Space Station. The P6 comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the International Space Station. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. The mission includes two spacewalks by Noriega and Tanner to complete the solar array connections. STS-97 is scheduled to launch Nov. 30 at about 10:06 p.m. EST

KSC-00pp1723

NASA Image and Video Library

2000-10-27

In the Space Station Processing Facility, STS-97 Mission Specialists Carlos Noriega (left) and Joe Tanner check out the mission payload, the P6 integrated truss segment. Mission STS-97 is the sixth construction flight to the International Space Station. The P6 comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the International Space Station. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. The mission includes two spacewalks by Noriega and Tanner to complete the solar array connections. STS-97 is scheduled to launch Nov. 30 at about 10:06 p.m. EST

KSC-00pp1720

NASA Image and Video Library

2000-10-27

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility, STS-97 Mission Specialists Carlos Noriega (far left) and Joe Tanner (right) check out the mission payload, the P6 integrated truss segment. Mission STS-97 is the sixth construction flight to the International Space Station. The P6 comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the International Space Station. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. The mission includes two spacewalks by Noriega and Tanner to complete the solar array connections. STS-97 is scheduled to launch Nov. 30 at about 10:06 p.m. EST

KSC-00pp1779

NASA Image and Video Library

2000-11-30

STS-97 Mission Specialist Joseph Tanner signals thumbs up for launch as he dons his launch and entry suit. this is his third Shuttle flight.; Mission STS-97 is the sixth construction flight to the International Space Station. It is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the Space Station. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. The 11-day mission includes two spacewalks to complete the solar array connections. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity.. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. Launch is scheduled for Nov. 30 at 10:06 p.m. EST

KSC-00pp1722

NASA Image and Video Library

2000-10-27

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility, STS-97 Mission Specialists Carlos Noriega (left) and Joe Tanner check out the mission payload, the P6 integrated truss segment. Mission STS-97 is the sixth construction flight to the International Space Station. The P6 comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the International Space Station. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. The mission includes two spacewalks by Noriega and Tanner to complete the solar array connections. STS-97 is scheduled to launch Nov. 30 at about 10:06 p.m. EST

KSC-00pp1782

NASA Image and Video Library

2000-11-30

STS-97 Pilot Michael Bloomfield signals thumbs up for launch after donning his launch and entry suit. This is his second Shuttle flight. Mission STS-97 is the sixth construction flight to the International Space Station. It is transporting the P6 Integrated Truss Structure that comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the Space Station. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. The 11-day mission includes two spacewalks to complete the solar array connections. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. Launch is scheduled for Nov. 30 at 10:06 p.m. EST

KSC00pp1722

NASA Image and Video Library

2000-10-27

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility, STS-97 Mission Specialists Carlos Noriega (left) and Joe Tanner check out the mission payload, the P6 integrated truss segment. Mission STS-97 is the sixth construction flight to the International Space Station. The P6 comprises Solar Array Wing-3 and the Integrated Electronic Assembly, to be installed on the International Space Station. The Station’s electrical power system will use eight photovoltaic solar arrays, each 112 feet long by 39 feet wide, to convert sunlight to electricity. The solar arrays are mounted on a “blanket” that can be folded like an accordion for delivery. Once in orbit, astronauts will deploy the blankets to their full size. Gimbals will be used to rotate the arrays so that they will face the Sun to provide maximum power to the Space Station. The mission includes two spacewalks by Noriega and Tanner to complete the solar array connections. STS-97 is scheduled to launch Nov. 30 at about 10:06 p.m. EST

Pilot ejection, parachute, and helicopter crash injuries.

PubMed

McBratney, Colleen M; Rush, Stephen; Kharod, Chetan U

2014-01-01

USAF Pararescuemen (PJs) respond to downed aircrew as a fundamental mission for personnel recovery (PR), one of the Air Force's core functions. In addition to responding to these in Military settings, the PJs from the 212 Rescue Squadron routinely respond to small plane crashes in remote regions of Alaska. While there is a paucity of information on the latter, there have been articles detailing injuries sustained from helicopter crashes and while ejecting or parachuting from fixed wing aircraft. The following represents a new chapter added to the Pararescue Medical Operations Handbook, Sixth Edition (2014, editors Matt Wolf, MD, and Stephen Rush, MD, in press). It was designed to be a quick reference for PJs and their Special Operations flight surgeons to help with understanding of mechanism of injury with regard to pilot ejection, parachute, and helicopter accident injuries. It outlines the nature of the injuries sustained in such mishaps and provides an epidemiologic framework from which to approach the problem. 2014.

Full-scale Wind-tunnel and Flight Tests of a Fairchild 22 Airplane Equipped with a Fowler Flap

NASA Technical Reports Server (NTRS)

Dearborn, C H; Soule, H A

1936-01-01

Full-scale wind-tunnel and flight tests were made of a Fairchild 22 airplane equipped with a Fowler flap to determine the effect of the flap on the performance and control characteristics of the airplane. In the wind-tunnel tests of the airplane with the horizontal tail surfaces removed, the flap was found to increase the maximum lift coefficient from 1.27 to 2.41. In the flight test, the flap was found to decrease the minimum speed from 58.8 to 44.4 miles per hour. The required take-off run to attain an altitude of 50 feet was reduced from 935 feet to 700 feet by the use of the flap, the minimum distance being obtained with five-sixths full deflection. The landing run from a height of 50 feet was reduced one-third. The longitudinal and directional control was adversely affected by the flap, indicating that the design of the tail surfaces is more critical with a flapped than a plain wing.

Lift and moment coefficients expanded to the seventh power of frequency for oscillating rectangular wings in supersonic flow and applied to a specific flutter problem

NASA Technical Reports Server (NTRS)

Nelson, Herbert C; Rainey, Ruby A; Watkins, Charles E

1954-01-01

Linearized theory for compressible unsteady flow is used to derive the velocity potential and lift and moment coefficients in the form of oscillating rectangular wing moving at a constant supersonic speed. Closed expressions for the velocity potential and lift and moment coefficients associated with pitching and translation are given to seventh power of the frequency. These expressions extend the range of usefulness of NACA report 1028 in which similar expressions were derived to the third power of the frequency of oscillation. For example, at a Mach number of 10/9 the expansion of the potential to the third power is an accurate representation of the potential for values of the reduced frequency only up to about 0.08; whereas the expansion of the potential to the seventh power is an accurate representation for values of the reduced frequency up to about 0.2. The section and total lift and moment coefficients are discussed with the aid of several figures. In addition, flutter speeds obtained in the Mach number range from 10/9 to 10/6 for a rectangular wing of aspect ratio 4.53 by using section coefficients derived on the basis of three-dimensional flow are compared with flutter speeds for this wing obtained by using coefficients derived on the basis of two-dimensional flow.

A finite-step method for estimating the spanwise lift distribution of wings in symmetric, yawed, and rotary flight at low speeds

NASA Technical Reports Server (NTRS)

Krenkel, A. R.

1978-01-01

The finite-step method was programmed for computing the span loading and stability derivatives of trapezoidal shaped wings in symmetric, yawed, and rotary flight. Calculations were made for a series of different wing planforms and the results compared with several available methods for estimating these derivatives in the linear angle of attack range. The agreement shown was generally good except in a few cases. An attempt was made to estimate the nonlinear variation of lift with angle of attack in the high alpha range by introducing the measured airfoil section data into the finite-step method. The numerical procedure was found to be stable only at low angles of attack.

Finite Element Based HWB Centerbody Structural Optimization and Weight Prediction

NASA Technical Reports Server (NTRS)

Gern, Frank H.

2012-01-01

This paper describes a scalable structural model suitable for Hybrid Wing Body (HWB) centerbody analysis and optimization. The geometry of the centerbody and primary wing structure is based on a Vehicle Sketch Pad (VSP) surface model of the aircraft and a FLOPS compatible parameterization of the centerbody. Structural analysis, optimization, and weight calculation are based on a Nastran finite element model of the primary HWB structural components, featuring centerbody, mid section, and outboard wing. Different centerbody designs like single bay or multi-bay options are analyzed and weight calculations are compared to current FLOPS results. For proper structural sizing and weight estimation, internal pressure and maneuver flight loads are applied. Results are presented for aerodynamic loads, deformations, and centerbody weight.

Energetics and optimum motion of oscillating lifting surfaces of finite span

NASA Technical Reports Server (NTRS)

Ahmadi, A. R.; Widnall, S. E.

1986-01-01

In certain modes of animal propulsion in nature, such as bird flight and fish swimming, the efficiency compared to man-made vehicles is very high. In such cases, wing and tail motions are typically associated with relatively high Reynolds numbers, where viscous effects are confined to a thin boundary layer at the surface and a thin trailing wake. The propulsive forces, which are generated primarily by the inertial forces, can be calculated from potential-flow theory using linearized unsteady-wing theory (for small-amplitude oscillations). In the present study, a recently developed linearized, low-frequency, unsteady lifting-line theory is employed to calculate the (sectional and total) energetic quantities and optimum motion of an oscillating wing of finite span.

Coupled nonlinear aeroelasticity and flight dynamics of fully flexible aircraft

NASA Astrophysics Data System (ADS)

Su, Weihua

This dissertation introduces an approach to effectively model and analyze the coupled nonlinear aeroelasticity and flight dynamics of highly flexible aircraft. A reduced-order, nonlinear, strain-based finite element framework is used, which is capable of assessing the fundamental impact of structural nonlinear effects in preliminary vehicle design and control synthesis. The cross-sectional stiffness and inertia properties of the wings are calculated along the wing span, and then incorporated into the one-dimensional nonlinear beam formulation. Finite-state unsteady subsonic aerodynamics is used to compute airloads along lifting surfaces. Flight dynamic equations are then introduced to complete the aeroelastic/flight dynamic system equations of motion. Instead of merely considering the flexibility of the wings, the current work allows all members of the vehicle to be flexible. Due to their characteristics of being slender structures, the wings, tail, and fuselage of highly flexible aircraft can be modeled as beams undergoing three dimensional displacements and rotations. New kinematic relationships are developed to handle the split beam systems, such that fully flexible vehicles can be effectively modeled within the existing framework. Different aircraft configurations are modeled and studied, including Single-Wing, Joined-Wing, Blended-Wing-Body, and Flying-Wing configurations. The Lagrange Multiplier Method is applied to model the nodal displacement constraints at the joint locations. Based on the proposed models, roll response and stability studies are conducted on fully flexible and rigidized models. The impacts of the flexibility of different vehicle members on flutter with rigid body motion constraints, flutter in free flight condition, and roll maneuver performance are presented. Also, the static stability of the compressive member of the Joined-Wing configuration is studied. A spatially-distributed discrete gust model is incorporated into the time simulation of the framework. Gust responses of the Flying-Wing configuration subject to stall effects are investigated. A bilinear torsional stiffness model is introduced to study the skin wrinkling due to large bending curvature of the Flying-Wing. The numerical studies illustrate the improvements of the existing reduced-order formulation with new capabilities of both structural modeling and coupled aeroelastic and flight dynamic analysis of fully flexible aircraft.

The Effectiveness at High Speeds of a 20-Percent-Chord Plain Trailing-Edge Flap on the NACA 65-210 Airfoil

NASA Technical Reports Server (NTRS)

Stivers, Louis S., Jr.

1947-01-01

An analysis has been made of the lift control effectiveness of a 20-percent-chord plain trailing-edge flap on the NACA 65-210 airfoil section from section lift-coefficient data obtained at Mach numbers from 0.3 to 0.875. In addition, the effectiveness of the plain flap as a lift-control device has been compared with the corresponding effectiveness of both a spoiler and a dive-recovery flap on the NACA 65-210 airfoil section. The analysis indicates that the plain trailing-edge flap employed on the 10-percent-thick airfoil at Mach numbers as high as 0.875 retains at least 50-percent of its low-speed lift-control effectiveness, and is sufficiently effective in lateral control application, assuming a rigid wing, to provide adequate airplane rolling characteristics. The plain trailing-edge flap, as compared to the spoiler and the dive-recovery flap, appears to afford the most favorable characteristics as a device for controlling lift continuously throughout the range of Mach numbers from 0.3 to 0.875. At Mach numbers above those for lift divergence of the wing, either a plain flap or a dive-recovery flap may be used on a thin airplane wing to provide auxiliary wing lift when the airplane is to be controlled in flight, other than in dives, at these Mach numbers. The choice of a lift-control device for this use, however, should include the consideration of other factors such as the increments of drag and pitching moment accompanying the use of the device, and the structural and high-speed aerodynamic characteristics of the airplane which is to employ the device.

Supercritical wing sections 2, volume 108

NASA Technical Reports Server (NTRS)

Bauer, F.; Garabedian, P.; Korn, D.; Jameson, A.; Beckmann, M. (Editor); Kuenzi, H. P. (Editor)

1975-01-01

A mathematical theory for the design and analysis of supercritical wing sections was previously presented. Examples and computer programs showing how this method works were included. The work on transonics is presented in a more definitive form. For design, a better model of the trailing edge is introduced which should eliminate a loss of fifteen or twenty percent in lift experienced with previous heavily aft loaded models, which is attributed to boundary layer separation. How drag creep can be reduced at off-design conditions is indicated. A rotated finite difference scheme is presented that enables the application of Murman's method of analysis in more or less arbitrary curvilinear coordinate systems. This allows the use of supersonic as well as subsonic free stream Mach numbers and to capture shock waves as far back on an airfoil as desired. Moreover, it leads to an effective three dimensional program for the computation of transonic flow past an oblique wing. In the case of two dimensional flow, the method is extended to take into account the displacement thickness computed by a semi-empirical turbulent boundary layer correction.

The impact of circulation control on rotary aircraft controls systems

NASA Technical Reports Server (NTRS)

Kingloff, R. F.; Cooper, D. E.

1987-01-01

Application of circulation to rotary wing systems is a new development. Efforts to determine the near and far field flow patterns and to analytically predict those flow patterns have been underway for some years. Rotary wing applications present a new set of challenges in circulation control technology. Rotary wing sections must accommodate substantial Mach number, free stream dynamic pressure and section angle of attack variation at each flight condition within the design envelope. They must also be capable of short term circulation blowing modulation to produce control moments and vibration alleviation in addition to a lift augmentation function. Control system design must provide this primary control moment, vibration alleviation and lift augmentation function. To accomplish this, one must simultaneously control the compressed air source and its distribution. The control law algorithm must therefore address the compressor as the air source, the plenum as the air pressure storage and the pneumatic flow gates or valves that distribute and meter the stored pressure to the rotating blades. Also, mechanical collective blade pitch, rotor shaft angle of attack and engine power control must be maintained.

Body-surface pressure data on two monoplane-wing missile configurations with elliptical cross sections at Mach 2.50

NASA Technical Reports Server (NTRS)

Allen, J. M.; Hernandez, G.; Lamb, M.

1983-01-01

Tabulated body surface pressure data for two monoplane-wing missile configurations are presented and analyzed. Body pressure data are presented for body-alone, body-tail, and body-wing-tail combinations. For the lost combination, data are presented for tail-fin deflection angles of 0 deg and 30 deg to simulate pitch, yaw, and roll control for both configurations. The data cover angles of attack from -5 deg to 25 deg and angles of roll from 0 deg to 90 deg at a Mach number of 2.50 and a Reynolds number of 6.56 x 1,000,000 per meter. Very consistent, systematic trends with angle of attack and angle of roll were observed in the data, and very good symmetry was found at a roll angle of 0 deg. Body pressures depended strongly on the local body cross-section shape, with very little dependence on the upstream shape. Undeflected fins had only a small influence on the pressures on the aft end of the body; however, tail-fin deflections caused large changes in the pressures.

Enhancement of roll maneuverability using post-reversal design

NASA Astrophysics Data System (ADS)

Li, Wei-En

This dissertation consists of three main parts. The first part is to discuss aileron reversal problem for a typical section with linear aerodynamic and structural analysis. The result gives some insight and ideas for this aeroelastic problem. Although the aileron in its post-reversal state will work the opposite of its design, this type of phenomenon as a design root should not be ruled out on these grounds alone, as current active flight-control systems can compensate for this. Moreover, one can get considerably more (negative) lift for positive flap angle in this unusual regime than positive lift for positive flap angle in the more conventional setting. This may have important implications for development of highly maneuverable aircraft. The second part is to involve the nonlinear aerodynamic and structural analyses into the aileron reversal problem. Two models, a uniform cantilevered lifting surface and a rolling aircraft with rectangular wings, are investigated here. Both models have trailing-edge control surfaces attached to the main wings. A configuration that reverses at a relatively low dynamic pressure and flies with the enhanced controls at a higher level of effectiveness is demonstrated. To evaluate how reliable for the data from XFOIL, the data for the wing-aileron system from advanced CFD codes and experiment are used to compare with that from XFOIL. To enhance rolling maneuverability for an aircraft, the third part is to search for the optimal configuration during the post-reversal regime from a design point of view. Aspect ratio, hinge location, airfoil dimension, inner structure of wing section, composite skin, aeroelastic tailoring, and airfoil selection are investigated for cantilevered wing and rolling aircraft models, respectively. Based on these parametric structural designs as well as the aerodynamic characteristics of different airfoils, recommendations are given to expand AAW flight program.

10 CFR 433.3 - Materials incorporated by reference.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Materials incorporated by reference. 433.3 Section 433.3 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL.... Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program, Sixth...

10 CFR 433.3 - Materials incorporated by reference.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Materials incorporated by reference. 433.3 Section 433.3 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL.... Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program, Sixth...

10 CFR 433.3 - Materials incorporated by reference.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Materials incorporated by reference. 433.3 Section 433.3 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL.... Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program, Sixth...

Theme Binders: One Size Fits All.

ERIC Educational Resources Information Center

Baskwill, Steve

1996-01-01

Describes theme binders designed by sixth graders as an independent study component that unites the class as a learning community, showcases student work, and illustrates developmental milestones for parents. Details theme binder components: (1) cover page; (2) introductory page outlining the theme and contents; (3) evaluation sections indicating…

F-16XL Hybrid Reynolds-Averaged Navier-Stokes/Large Eddy Simulation on Unstructured Grids

NASA Technical Reports Server (NTRS)

Park, Michael A.; Abdol-Hamid, Khaled S.; Elmiligui, Alaa

2015-01-01

This study continues the Cranked Arrow Wing Aerodynamics Program, International (CAWAPI) investigation with the FUN3D and USM3D flow solvers. CAWAPI was established to study the F-16XL, because it provides a unique opportunity to fuse fight test, wind tunnel test, and simulation to understand the aerodynamic features of swept wings. The high-lift performance of the cranked-arrow wing planform is critical for recent and past supersonic transport design concepts. Simulations of the low speed high angle of attack Flight Condition 25 are compared: Detached Eddy Simulation (DES), Modi ed Delayed Detached Eddy Simulation (MDDES), and the Spalart-Allmaras (SA) RANS model. Iso- surfaces of Q criterion show the development of coherent primary and secondary vortices on the upper surface of the wing that spiral, burst, and commingle. SA produces higher pressure peaks nearer to the leading-edge of the wing than flight test measurements. Mean DES and MDDES pressures better predict the flight test measurements, especially on the outer wing section. Vorticies and vortex-vortex interaction impact unsteady surface pressures. USM3D showed many sharp tones in volume points spectra near the wing apex with low broadband noise and FUN3D showed more broadband noise with weaker tones. Spectra of the volume points near the outer wing leading-edge was primarily broadband for both codes. Without unsteady flight measurements, the flight pressure environment can not be used to validate the simulations containing tonal or broadband spectra. Mean forces and moment are very similar between FUN3D models and between USM3D models. Spectra of the unsteady forces and moment are broadband with a few sharp peaks for USM3D.

Aerodynamic characteristics of three slender sharp-edge 74 degrees swept wings at subsonic, transonic, and supersonic Mach numbers

NASA Technical Reports Server (NTRS)

Davenport, E. E.

1974-01-01

Slender sharp-edge wings having leading-edge sweep angles of 74 deg have been studied at Mach numbers from 0.60 to 2.80, at angles of attack from about minus 4 deg to 22 deg, and at angles of sideslip from 0 deg to 5 deg. The wings had delta, arrow, and diamond planforms. The experimental tests were made in the Langley 8-foot transonic pressure tunnel and the Langley Unitary Plan wind tunnel test section number 1. The theoretical predictions were made using the theories of NASA TN D-3767 and NASA TN D-6243. The results of the study indicated that the lift and drag characteristics as affected by planform and Mach number could be reasonably well predicted for the delta wing in the subsonic and transonic Mach number range. In the supersonic range, the delta and diamond wings were about equally good in the degree of agreement between experiment and theory. In making drag-due-to-lift predictions the vortex lift effects must be taken into account if reasonable results are to be obtained at moderate or high lift coefficients.

Water Tunnel Flow Visualization Study Through Poststall of 12 Novel Planform Shapes

NASA Technical Reports Server (NTRS)

Gatlin, Gregory M.; Neuhart, Dan H.

1996-01-01

To determine the flow field characteristics of 12 planform geometries, a flow visualization investigation was conducted in the Langley 16- by 24-Inch Water Tunnel. Concepts studied included flat plate representations of diamond wings, twin bodies, double wings, cutout wing configurations, and serrated forebodies. The off-surface flow patterns were identified by injecting colored dyes from the model surface into the free-stream flow. These dyes generally were injected so that the localized vortical flow patterns were visualized. Photographs were obtained for angles of attack ranging from 10' to 50', and all investigations were conducted at a test section speed of 0.25 ft per sec. Results from the investigation indicate that the formation of strong vortices on highly swept forebodies can improve poststall lift characteristics; however, the asymmetric bursting of these vortices could produce substantial control problems. A wing cutout was found to significantly alter the position of the forebody vortex on the wing by shifting the vortex inboard. Serrated forebodies were found to effectively generate multiple vortices over the configuration. Vortices from 65' swept forebody serrations tended to roll together, while vortices from 40' swept serrations were more effective in generating additional lift caused by their more independent nature.

Reinforcements in avian wing bones: Experiments, analysis, and modeling.

PubMed

Novitskaya, E; Ruestes, C J; Porter, M M; Lubarda, V A; Meyers, M A; McKittrick, J

2017-12-01

Almost all species of modern birds are capable of flight; the mechanical competency of their wings and the rigidity of their skeletal system evolved to enable this outstanding feat. One of the most interesting examples of structural adaptation in birds is the internal structure of their wing bones. In flying birds, bones need to be sufficiently strong and stiff to withstand forces during takeoff, flight, and landing, with a minimum of weight. The cross-sectional morphology and presence of reinforcing structures (struts and ridges) found within bird wing bones vary from species to species, depending on how the wings are utilized. It is shown that both morphology and internal features increases the resistance to flexure and torsion with a minimum weight penalty. Prototypes of reinforcing struts fabricated by 3D printing were tested in diametral compression and torsion to validate the concept. In compression, the ovalization decreased through the insertion of struts, while they had no effect on torsional resistance. An elastic model of a circular ring reinforced by horizontal and vertical struts is developed to explain the compressive stiffening response of the ring caused by differently oriented struts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aerodynamic design for improved manueverability by use of three-dimensional transonic theory

NASA Technical Reports Server (NTRS)

Mann, M. J.; Campbell, R. L.; Ferris, J. C.

1984-01-01

Improvements in transonic maneuver performance by the use of three-dimensional transonic theory and a transonic design procedure were examined. The FLO-27 code of Jameson and Caughey was used to design a new wing for a fighter configuration with lower drag at transonic maneuver conditions. The wing airfoil sections were altered to reduce the upper-surface shock strength by means of a design procedure which is based on the iterative application of the FLO-27 code. The plan form of the fighter configuration was fixed and had a leading edge sweep of 45 deg and an aspect ratio of 3.28. Wind-tunnel tests were conducted on this configuration at Mach numbers from 0.60 to 0.95 and angles of attack from -2 deg to 17 deg. The transonic maneuver performance of this configuration was evaluated by comparison with a wing designed by empirical methods and a wing designed primarily by two-dimensional transonic theory. The configuration designed by the use of FLO-27 had the same or lower drag than the empirical wing and, for some conditions, lower drag than the two-dimensional design. From some maneuver conditions, the drag of the two-dimensional design was somewhat lower.

Composite transport wing technology development: Design development tests and advanced structural concepts

NASA Technical Reports Server (NTRS)

Griffin, Charles F.; Harvill, William E.

1988-01-01

Numerous design concepts, materials, and manufacturing methods were investigated for the covers and spars of a transport box wing. Cover panels and spar segments were fabricated and tested to verify the structural integrity of design concepts and fabrication techniques. Compression tests on stiffened panels demonstrated the ability of graphite/epoxy wing upper cover designs to achieve a 35 percent weight savings compared to the aluminum baseline. The impact damage tolerance of the designs and materials used for these panels limits the allowable compression strain and therefore the maximum achievable weight savings. Bending and shear tests on various spar designs verified an average weight savings of 37 percent compared to the aluminum baseline. Impact damage to spar webs did not significantly degrade structural performance. Predictions of spar web shear instability correlated well with measured performance. The structural integrity of spars manufactured by filament winding equalled or exceeded those fabricated by hand lay-up. The information obtained will be applied to the design, fabrication, and test of a full-scale section of a wing box. When completed, the tests on the technology integration box beam will demonstrate the structural integrity of an advanced composite wing design which is 25 percent lighter than the metal baseline.

Development, Analysis and Testing of the High Speed Research Flexible Semispan Model

NASA Technical Reports Server (NTRS)

Schuster, David M.; Spain, Charles V.; Turnock, David L.; Rausch, Russ D.; Hamouda, M-Nabil; Vogler, William A.; Stockwell, Alan E.

1999-01-01

This report presents the work performed by Lockheed Martin Engineering and Sciences (LMES) in support of the High Speed Research (HSR) Flexible Semispan Model (FSM) wind-tunnel test. The test was conducted in order to assess the aerodynamic and aeroelastic character of a flexible high speed civil transport wing. Data was acquired for the purpose of code validation and trend evaluation for this type of wing. The report describes a number of activities in preparing for and conducting the wind-tunnel test. These included coordination of the design and fabrication, development of analytical models, analysis/hardware correlation, performance of laboratory tests, monitoring of model safety issues, and wind-tunnel data acquisition and reduction. Descriptions and relevant evaluations associated with the pretest data are given in sections 1 through 6, followed by pre- and post-test flutter analysis in section 7, and the results of the aerodynamics/loads test in section 8. Finally, section 9 provides some recommendations based on lessons learned throughout the FSM program.

Evaluation of viscous drag reduction schemes for subsonic transports

NASA Technical Reports Server (NTRS)

Marino, A.; Economos, C.; Howard, F. G.

1975-01-01

The results are described of a theoretical study of viscous drag reduction schemes for potential application to the fuselage of a long-haul subsonic transport aircraft. The schemes which were examined included tangential slot injection on the fuselage and various synergetic combinations of tangential slot injection and distributed suction applied to wing and fuselage surfaces. Both passive and mechanical (utilizing turbo-machinery) systems were examined. Overall performance of the selected systems was determined at a fixed subsonic cruise condition corresponding to a flight Mach number of free stream M = 0.8 and an altitude of 11,000 m. The nominal aircraft to which most of the performance data was referenced was a wide-body transport of the Boeing 747 category. Some of the performance results obtained with wing suction are referenced to a Lockheed C-141 Star Lifter wing section. Alternate designs investigated involved combinations of boundary layer suction on the wing surfaces and injection on the fuselage, and suction and injection combinations applied to the fuselage only.

Finite wing aerodynamics with simulated glaze ice

NASA Technical Reports Server (NTRS)

Khodadoust, A.; Bragg, M. B.; Kerho, M.; Wells, S.; Soltani, M. R.

1992-01-01

The effect of a simulated glaze ice accretion on the aerodynamic performance of a three-dimensional wing is studied experimentally. The model used for these tests was a semi-span wing of effective aspect ratio five, mounted from the sidewall of the UIUC subsonic wind tunnel. The model has an NACA 0012 airfoil section on a rectangular, untwisted planform with interchangeable leading edges to allow for testing both the baseline and the iced wing geometry. A three-component sidewall balance was used to measure lift, drag and pitching moment on the clean and iced model. A four-beam two-color fiberoptic laser Doppler velocimeter (LDV) was used to map the flowfield along several spanwise cuts on the model. Preliminary results from LDV scans, which will be the bulk of this paper, are presented following the force balance measurement results. Initial comparison of LDV surveys compare favorably with inviscid theory results and 2D split hot-film measurements near the model surface.

Structural characterization of Papilio kotzebuea (Eschscholtz 1821) butterfly wings

NASA Astrophysics Data System (ADS)

Sackey, J.; Nuru, Z. Y.; Berthier, S.; Maaza, M.

2018-05-01

The `plain black' forewings and black with `red spot' hindwings of the Papilio kotzebuea (Eschscholtz, 1821) were characterized by Scanning Electron Microscopy (SEM), Energy-Dispersive x-ray Spectroscopy (EDS), Atomic Force Microscopy (AFM), Fourier transform Infrared spectroscopy (FT-IR), UV-Vis spectrophometer and NIRQuest spectrometer. SEM images showed that the two sections of wings have different structures. The black with `red spot' hindwings have `hair-like' structures attached to the ridges and connected to the lamellae. On the contrary, the `plain black' forewings have holes that separate the ridges. AFM analysis unveiled that the `plain black' forewings have higher average surfaces roughness values as compared with the black with `red spot' hindwing. EDS and FT-IR results confirmed the presence of naturally hydrophobic materials on the wings. The `plain black' forewing exhibited strong absorptance (97%) throughout the solar spectrum range, which is attributed to the high melanin concentration as well as to the presence of holes in the scales. Biomimicking this wing could serves as equivalent solar absorber material.

Noise tests of a model engine-over-the-wing STOL configuration using a multijet nozzle with deflector

NASA Technical Reports Server (NTRS)

Olsen, W. A.; Friedman, R.

1973-01-01

Noise data were obtained with a small scale model stationary STOL configuration that used an eight lobe mixer nozzle with deflector mounted above a 32-cm-chord wing section. The factors varied to determine their effect upon the noise were wing flap angle, nozzle shape, nozzle location, deflector configuration, and jet velocity. The noise from the mixer nozzle model was compared to the noise from a model using a circular nozzle of the same area. The mixer nozzle model was quieter at the low to middle frequencies, while the circular nozzle was quieter at high frequencies. The perceived noise level (PNL) was calculated for an aircraft 10 times larger than the model. The PNL at 500 feet for the mixer nozzle turned out to be within 1 db of the PNL for the circular nozzle. For some configurations at highly directional broadband noise, which could be eliminated by changes in nozzle and/or deflector location, occurred below the wing.

Working charts for the determination of the lift distribution between biplane wings

NASA Technical Reports Server (NTRS)

Kuhn, Paul

1934-01-01

In this report are presented empirical working charts from which the distribution of lift between wings, that is the fraction of the total lift borne by each, can be determined in the positive lift range for any ordinary biplane cellule whose individual wings have the same profile. The variables taken directly into account include airfoil section, stagger, gap/chord ratio, decalage, chord ratio, and overhang. It is shown that the influence of unequal sweepback and unequal dihedral in upper and lower wings may be properly provided for by utilizing the concepts of average stagger and average gap/chord ratio, respectively. The effect of other variables is discussed, but they have not been included in the charts either because their influence was obviously small or because insufficient data existed to make possible a complete determination of their influence. All available pertinent biplane data were analyzed in establishing the charts, and in some cases theoretical relationships were utilized to establish qualitative tendencies.

Ko Displacement Theory for Structural Shape Predictions

NASA Technical Reports Server (NTRS)

Ko, William L.

2010-01-01

The development of the Ko displacement theory for predictions of structure deformed shapes was motivated in 2003 by the Helios flying wing, which had a 247-ft (75-m) wing span with wingtip deflections reaching 40 ft (12 m). The Helios flying wing failed in midair in June 2003, creating the need to develop new technology to predict in-flight deformed shapes of unmanned aircraft wings for visual display before the ground-based pilots. Any types of strain sensors installed on a structure can only sense the surface strains, but are incapable to sense the overall deformed shapes of structures. After the invention of the Ko displacement theory, predictions of structure deformed shapes could be achieved by feeding the measured surface strains into the Ko displacement transfer functions for the calculations of out-of-plane deflections and cross sectional rotations at multiple locations for mapping out overall deformed shapes of the structures. The new Ko displacement theory combined with a strain-sensing system thus created a revolutionary new structure- shape-sensing technology.

Flow field predictions for a slab delta wing at incidence

NASA Technical Reports Server (NTRS)

Conti, R. J.; Thomas, P. D.; Chou, Y. S.

1972-01-01

Theoretical results are presented for the structure of the hypersonic flow field of a blunt slab delta wing at moderately high angle of attack. Special attention is devoted to the interaction between the boundary layer and the inviscid entropy layer. The results are compared with experimental data. The three-dimensional inviscid flow is computed numerically by a marching finite difference method. Attention is concentrated on the windward side of the delta wing, where detailed comparisons are made with the data for shock shape and surface pressure distributions. Surface streamlines are generated, and used in the boundary layer analysis. The three-dimensional laminar boundary layer is computed numerically using a specially-developed technique based on small cross-flow in streamline coordinates. In the rear sections of the wing the boundary layer decreases drastically in the spanwise direction, so that it is still submerged in the entropy layer at the centerline, but surpasses it near the leading edge. Predicted heat transfer distributions are compared with experimental data.

Method for calculating lift distributions for unswept wings with flaps or ailerons by use of nonlinear section lift data

NASA Technical Reports Server (NTRS)

Sivells, James C; Westrick, Gertrude C

1952-01-01

A method is presented which allows the use of nonlinear section lift data in the calculation of the spanwise lift distribution of unswept wings with flaps or ailerons. This method is based upon lifting line theory and is an extension to the method described in NACA rep. 865. The mathematical treatment of the discontinuity in absolute angle of attack at the end of the flap or aileron involves the use of a correction factor which accounts for the inability of a limited trigonometric series to represent adequately the spanwise lift distribution. A treatment of the apparent discontinuity in maximum section lift coefficient is also described. Simplified computing forms containing detailed examples are given for both symmetrical and asymmetrical lift distributions. A few comparisons of calculated characteristics with those obtained experimentally are also presented.

A modeling approach to energy savings of flying Canada geese using computational fluid dynamics.

PubMed

Maeng, Joo-Sung; Park, Jae-Hyung; Jang, Seong-Min; Han, Seog-Young

2013-03-07

A flapping flight mechanism of the Canada goose (Branta canadensis) was estimated using a two-jointed arm model in unsteady aerodynamic performance to examine how much energy can be saved in migration. Computational fluid dynamics (CFD) was used to evaluate airflow fields around the wing and in the wake. From the distributions of velocity and pressure on the wing, it was found that about 15% of goose flight energy could be saved by drag reduction from changing the morphology of the wing. From the airflow field in the wake, it was found that a pair of three-dimensional spiral flapping advantage vortices (FAV) was alternately generated. We quantitatively deduced that the optimal depth (the distance along the flight path between birds) was around 4m from the wing tip of a goose ahead, and optimal wing tip spacing (WTS, the distance between wing tips of adjacent birds perpendicular to the flight path) ranged between 0 and -0.40m in the spanwise section. It was found that a goose behind can save about 16% of its energy by induced power from FAV in V-formation. The phase difference of flapping between the goose ahead and behind was estimated at around 90.7° to take full aerodynamic benefit caused by FAV. Copyright © 2012 Elsevier Ltd. All rights reserved.

Application of lightweight materials in structure concept design of large-scale solar energy unmanned aerial vehicle

NASA Astrophysics Data System (ADS)

Zhang, Wei; Lv, Shengli; Guan, XiQi

2017-09-01

Carbon fiber composites and film materials can be effectively used in light aircraft structures, especially for solar unmanned aerial vehicles. The use of light materials can reduce the weight of the aircraft, but also can effectively improve the aircraft's strength and stiffness. The structure of the large aspect ratio solar energy UAV was analyzed in detail, taking Solar-impulse solar aircraft as an example. The solar energy UAV has a wing aspect ratio greater than 20, and the detailed digital model of the wing structure including beam, ribs and skin was built, also the Finite Element Method was applied to analyze the static and dynamic performance of the structure. The upper skin of the wing is covered with silicon solar cells, while the lower skin is light and transparent film. The single beam truss form of carbon fiber lightweight material is used in the wing structure. The wing beam is a box beam with rectangular cross sections. The box beam connected the front parts and after parts of the ribs together. The fuselage of the aircraft was built by space truss structure. According to the static and dynamic analysis with Finite Element method, it was found that the aircraft has a small wingtip deflection relative to the wingspan in the level flight state. The first natural frequency of the wing structure is pretty low, which is closed to the gust load.

Glans wings are separated ventrally by the septum glandis and frenulum penis: MRI documentation and surgical implications

PubMed Central

Özbey, Hüseyin; Kumbasar, Ali

2017-01-01

Objective In the normal human penis, the glans wings are in apposition in the midline ventrally, and are separated by the “septum glandis” and “frenulum” of the prepuce. However, most of the hypospadias repair techniques include dissection of the glans wings and their approximation enclosing the neourethra within the glans. Material and methods In order to obtain detailed information about the normal anatomy of glans penis, magnetic resonance imaging (MRI) findings of the penis were studied in three adults. Transverse, and sagittal sections of the penis were performed with a 1.5-T MRI scanner. Results The present MRI study has confirmed that the glans wings do not fuse at the ventral midline and they are seperated by a fibrous tissue (septum glandis). This fibrous tissue is connected to the frenulum, traversing the wings of the glans penis. The glanular urethra forming the fossa navicularis has a wider caliber than the proximal urethra, and its walls are radiologically seen as the extension of that fibrous tissue. Conclusion The male urethra is not a uniform tubular structure and has distinct attachments in glans penis. The glans wings are separated ventrally by the septum glandis and frenulum. In hypospadias, the septum glandis and frenulum are entirely missing structures. Therefore, in hypospadias surgery, the anatomical features of the glanular urethra must be taken into consideration. PMID:29201519

Electron tomography and computer visualisation of a three-dimensional 'photonic' crystal in a butterfly wing-scale.

PubMed

Argyros, A; Manos, S; Large, M C J; McKenzie, D R; Cox, G C; Dwarte, D M

2002-01-01

A combination of transmission electron tomography and computer modelling has been used to determine the three-dimensional structure of the photonic crystals found in the wing-scales of the Kaiser-I-Hind butterfly (Teinopalpus imperialis). These scales presented challenges for electron microscopy because the periodicity of the structure was comparable to the thickness of a section and because of the complex connectivity of the object. The structure obtained has been confirmed by taking slices of the three-dimensional computer model constructed from the tomography and comparing these with transmission electron microscope (TEM) images of microtomed sections of the actual scale. The crystal was found to have chiral tetrahedral repeating units packed in a triclinic lattice.

Optimum structural design with static aeroelastic constraints

NASA Technical Reports Server (NTRS)

Bowman, Keith B; Grandhi, Ramana V.; Eastep, F. E.

1989-01-01

The static aeroelastic performance characteristics, divergence velocity, control effectiveness and lift effectiveness are considered in obtaining an optimum weight structure. A typical swept wing structure is used with upper and lower skins, spar and rib thicknesses, and spar cap and vertical post cross-sectional areas as the design parameters. Incompressible aerodynamic strip theory is used to derive the constraint formulations, and aerodynamic load matrices. A Sequential Unconstrained Minimization Technique (SUMT) algorithm is used to optimize the wing structure to meet the desired performance constraints.

Charts for Determining Preliminary Values of Span-load, Shear, Bending-moment, and Accumulated-torque Distributions of Swept Wings of Various Taper Ratios

NASA Technical Reports Server (NTRS)

Wollner, Bertram C

1948-01-01

Contains charts for use in determining preliminary values of the spanwise-load, shear, bending-moment, and accumulated-torque distributions of swept wings. The charts are based on strip theory and include four aerodynamic-load distributions, two section-moment distributions, and two inertia-load distributions. The taper ratios considered cover the range from 1.0 to 0 and the results are applicable to any angle of sweep.

Numerical and Analytical Study of Nonlinear Effects of Transonic Flow Past a Wing Airfoil in Oscillation of its Surface Element

NASA Astrophysics Data System (ADS)

Aul'chenko, S. M.; Zamuraev, V. P.; Kalinina, A. P.

2014-05-01

The present work is devoted to a criterial analysis and mathematical modeling of the influence of forced oscillations of surface elements of a wing airfoil on the shock-wave structure of transonic flow past it. Parameters that govern the regimes of interaction of the oscillatory motion of airfoil sections with the breakdown compression shock have been established. The qualitative and quantitative influence of these parameters on the wave resistance of the airfoil has been investigated.

ADST System Test Report for the Rotary Wing Aircraft Airnet Aeromodel and Weapon Model Merge with the ATAC 2 Baseline

DTIC Science & Technology

1994-01-20

Category 2 - Investigation/Debug Required ..................................... 11 Table 3-1 Field Test Report Status/Corrective Action...in Table 3-1 in section 3.1. The Field Test Reports and SP/CR’s are listed below for the two categories: Table 3.0-1. Category 1 - LADS PMO Direction...symbology, consisting Wing Aircraft of the laser code A - H plus the four digit data field shall be displayed for 10 seconds, after which time only

Meeting Unmanned Air Vehicle Platform Challenges Using Oblique Wing Aircraft

DTIC Science & Technology

2007-11-01

effects need to be assessed with fully relaxed wakes (Section 5). 4.2 Oblique Flying Wing with 75o Folded Tip / Winglet , Mach 0.8, CL = 0.3 Fig.9 (a...e) refers to an OFW flying at 30o sweep with 75o folded tip or winglet , Ref.14. This also acts as a vertical fin or as a control (deflection...design problem. The resultant Cp-x distributions (e) at the design condition are well behaved. The distributions on the winglet are slightly more

Design of a high altitude long endurance flying-wing solar-powered unmanned air vehicle

NASA Astrophysics Data System (ADS)

Alsahlani, A. A.; Johnston, L. J.; Atcliffe, P. A.

2017-06-01

The low-Reynolds number environment of high-altitude §ight places severe demands on the aerodynamic design and stability and control of a high altitude, long endurance (HALE) unmanned air vehicle (UAV). The aerodynamic efficiency of a §ying-wing configuration makes it an attractive design option for such an application and is investigated in the present work. The proposed configuration has a high-aspect ratio, swept-wing planform, the wing sweep being necessary to provide an adequate moment arm for outboard longitudinal and lateral control surfaces. A design optimization framework is developed under a MATLAB environment, combining aerodynamic, structural, and stability analysis. Low-order analysis tools are employed to facilitate efficient computations, which is important when there are multiple optimization loops for the various engineering analyses. In particular, a vortex-lattice method is used to compute the wing planform aerodynamics, coupled to a twodimensional (2D) panel method to derive aerofoil sectional characteristics. Integral boundary-layer methods are coupled to the panel method in order to predict §ow separation boundaries during the design iterations. A quasi-analytical method is adapted for application to flyingwing con¦gurations to predict the wing weight and a linear finite-beam element approach is used for structural analysis of the wing-box. Stability is a particular concern in the low-density environment of high-altitude flight for flying-wing aircraft and so provision of adequate directional stability and control power forms part of the optimization process. At present, a modified Genetic Algorithm is used in all of the optimization loops. Each of the low-order engineering analysis tools is validated using higher-order methods to provide con¦dence in the use of these computationally-efficient tools in the present design-optimization framework. This paper includes the results of employing the present optimization tools in the design of a HALE, flying-wing UAV to indicate that this is a viable design configuration option.

Student Preparation Workbook for Outdoor School Attendance.

ERIC Educational Resources Information Center

Gilfillan, Warren C.; And Others

Sixth grade students can prepare for the Multnomah County, Oregon, Outdoor School experience by completing the workbook designed to provide fundamental information about soil, water, plant, and animal resources. The workbook begins with an introduction to environmental manners, after which a section is devoted to each resource area. The glossary…

77 FR 25524 - Sixth Meeting: RTCA, NextGen Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-30

... provide the following information: Name (as it appears on your identification), Company, Phone number, Country of origin. FOR FURTHER INFORMATION CONTACT: The RTCA Secretariat, 1150 18th Street NW., Suite 910....rtca.org . SUPPLEMENTARY INFORMATION: Pursuant to section 10(a)(2) of the Federal Advisory Committee...

Facts & Figures, 1999: A Compendium of Statistics on Ontario Universities.

ERIC Educational Resources Information Center

Council of Ontario Universities, Toronto.

This is the sixth edition of statistical and graphical information on the Ontario (Canada) university system. The report contains six sections: (1) Ontario population data, which includes population projections to 2021, income and employment rates by educational attainment, and university participation rates; (2) applicant/registrant data, which…

Teaching Nutrition in the Elementary School.

ERIC Educational Resources Information Center

Banks, Mary Alice; Dunham, Margaret A.

This teaching manual is divided into three sections: (1) basic information on nutrition for teachers, (2) activities for learning about nutrition, suitable for first through third grades and fourth through sixth, and (3) sources of teaching aids and information on nutrition. Subjects include the four food groups, nutrients and principal food…

Young Girls' Eating Attitudes and Body Image Dissatisfaction: Associations with Communication and Modeling

ERIC Educational Resources Information Center

Kichler, Jessica C.; Crowther, Janis H.

2009-01-01

The relationships among communication, modeling, body image dissatisfaction, and maladaptive eating attitudes and behaviors in preadolescent girls were investigated in a cross-sectional study of 69 girls in fourth through sixth grade and their mothers. Participants completed questionnaires assessing familial and peer influences, body image…

10 CFR 435.3 - Materials incorporated by reference.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Materials incorporated by reference. 435.3 Section 435.3 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE... Renewable Energy, Building Technologies Program, Sixth Floor, 950 L'Enfant Plaza, SW., Washington, DC 20024...

10 CFR 435.3 - Materials incorporated by reference.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Materials incorporated by reference. 435.3 Section 435.3 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE... Renewable Energy, Building Technologies Program, Sixth Floor, 950 L'Enfant Plaza, SW., Washington, DC 20024...

10 CFR 435.3 - Materials incorporated by reference.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Materials incorporated by reference. 435.3 Section 435.3 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE... Renewable Energy, Building Technologies Program, Sixth Floor, 950 L'Enfant Plaza, SW., Washington, DC 20024...

Middle School Law Awareness Curriculum Guide, 1980.

ERIC Educational Resources Information Center

Seminole County Board of Public Instruction, Sanford, FL.

Materials, activities, and lesson plans for educating middle school students about the law and the legal system are presented. Materials for the sixth grade are contained in six sections: (1) Prehistoric Man; (2) Ancient Civilizations; (3) Ancient Greece; (4) Ancient Rome; (5) Medieval Civilizations; and (6) the Renaissance. Grade 7 has three…

Developmental Change in Proactive Interference.

ERIC Educational Resources Information Center

Kail, Robert

2002-01-01

Two studies examined age-related change in proactive interference from previously learned material. The meta-analysis of 26 studies indicated that proactive interference decreased with age. The cross-sectional study found that third through sixth graders' and college students' recall was accurate on Trial 1, but became less so over Trials 2…

College and Adult Reading, VI; Sixth Yearbook.

ERIC Educational Resources Information Center

Wark, David L., Ed.

This volume contains the sixteen papers presented to the 1968, 1969, and 1970 annual meetings of the North Central Reading Association. The papers are grouped into four sections: Programs and Centers, Materials and Techniques, Evaluation, and Professional Problems. Some of the topics concern tests and test-taking, attitudinal factors, descriptions…

Senda: Lectura 6 (Senda: Reader 6).

ERIC Educational Resources Information Center

Peniche Leger, Maria Elena, Ed.

This textbook, the sixth in a series of six, is designed to give the advanced elementary school student continued practice in reading Spanish. It contains some 30 sections with passages of increasing degrees of difficulty. Illustrations are included. The text includes selections from authors such as Inca Garcilaso de la Vega, Melville, Santos…

Toward Affective Development: A Program to Stimulate Psychological and Affective Development.

ERIC Educational Resources Information Center

Pearl, Linda F.

1987-01-01

Toward Affective Development (TAD), a 191-lesson program designed to stimulate psychological and affective development for third- through sixth-graders, can be used in special education, resource rooms, and remedial settings. TAD's five sections encompass: openness to experience, effects of emotions, group dynamics, individuality, and conflict…

Discover Brazil. A Unit of Study.

ERIC Educational Resources Information Center

Goobie, Kathy; And Others

These curriculum materials were designed to assist sixth grade teachers in the delivery of the world regions component of the grade six social studies. Activities engage students in thinking, analysis, and speculation with a blend of process and product exercises. The book is divided into five sections. "Introductory Activities" include:…

The Threshold Hypothesis Applied to Spatial Skill and Mathematics

ERIC Educational Resources Information Center

Freer, Daniel

2017-01-01

This cross-sectional study assessed the relation between spatial skills and mathematics in 854 participants across kindergarten, third grade, and sixth grade. Specifically, the study probed for a threshold for spatial skills when performing mathematics, above which spatial scores and mathematics scores would be significantly less related. This…

Osteological histology of the Pan-Alcidae (Aves, Charadriiformes): correlates of wing-propelled diving and flightlessness.

PubMed

Smith, N Adam; Clarke, Julia A

2014-02-01

Although studies of osteological morphology, gross myology, myological histology, neuroanatomy, and wing-scaling have all documented anatomical modifications associated with wing-propelled diving, the osteohistological study of this highly derived method of locomotion has been limited to penguins. Herein we present the first osteohistological study of the derived forelimbs and hind limbs of wing-propelled diving Pan-Alcidae (Aves, Charadriiformes). In addition to detailing differences between wing-propelled diving charadriiforms and nondiving charadriiforms, microstructural modifications to the humeri, ulnae and femora of extinct flightless pan-alcids are contrasted with those of volant alcids. Histological thin-sections of four species of pan-alcids (Alca torda, †Alca grandis, †Pinguinus impennis, †Mancalla cedrosensis) and one outgroup charadriiform (Stercorarius longicaudus) were compared. The forelimb bones of wing-propelled diving charadriiforms were found to have significantly thicker (∼22%) cortical bone walls. Additionally, as in penguins, the forelimbs of flightless pan-alcids are found to be osteosclerotic. However, unlike the pattern documented in penguins that display thickened cortices in both forelimbs and hind limbs, the forelimb and hind limb elements of pan-alcids display contrasting microstructural morphologies with thickened forelimb cortices and relatively thinner femoral cortices. Additionally, the identification of medullary bone in the sampled †Pinguinus impennis specimen suggests that further osteohistological investigation could provide an answer to longstanding questions regarding sexual dimorphism of Great Auks. Finally, these results suggest that it is possible to discern volant from flightless wing-propelled divers from fragmentary fossil remains. Copyright © 2013 Wiley Periodicals, Inc.

Beltzville Lake, Lehigh River Basin, Pohopoco Creek, Pennsylvania, Condition Report. Dam Outlet Works and Spillway

DTIC Science & Technology

1977-07-01

Paragraph Title Page SECTION 1 INTRODUCTION 1-01 Authority and Scope 1 1-02 Construction History 1 ’ 1-03 Inspection and Evaluation 1 SECTION 2 SIXTH...Report No. 6 SECTION 1 INTRODUCTION 1-01. AUTHORITY AND SCOPE. This report has been prepared in accordance with Engineer Regulation 1110-2-100 entitled...DATA ___________.. ... ..._____1975-1976 PLATE 4 t iZ .. .4 7 ....T . . jAUG . - SEPT - OCT’ NOV DE( -AN . FED MAR i’- o~y d!1 I -4 WEI IIi OZ [ 011. u

NASA's Helios Prototype aircraft taking off from the Pacific Missile Range Facility, Kauai, Hawaii,

NASA Technical Reports Server (NTRS)

2001-01-01

As a follow-on to the Centurion (and earlier Pathfinder and Pathfinder-Plus) aircraft, the solar-powered Helios Prototype is the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions in the stratosphere. Developed by AeroVironment, Inc., of Monrovia, California, under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project, the unique craft is intended to demonstrate two key missions: the ability to reach and sustain horizontal flight at 100,000 feet altitude on a single-day flight in 2001, and to maintain flight above 50,000 feet altitude for at least four days in 2003, with the aid of a regenerative fuel cell-based energy storage system now in development. Both of these missions will be powered by electricity derived from non-polluting solar energy. The Helios Prototype is an enlarged version of the Centurion flying wing, which flew a series of test flights at NASA's Dryden Flight Research Center in late 1998. The craft has a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of its solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. The remotely piloted, electrically powered Helios Prototype went aloft on its maiden low-altitude checkout flight Sept. 8, 1999, over Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center in the Southern California desert. The initial flight series was flown on battery power as a risk-reduction measure. In all, six flights were flown in the Helios Protoype's initial development series. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved aerodynamic efficiency, allowing the Helios Prototype to fly higher, longer and with a larger payload than the smaller craft. In addition, project engineers added a differential Global Positioning Satellite (GPS) system to improve navigation, an extensive turbulence monitoring system payload to record structural loads on the aircraft both in the air and on the ground, and radiator plates to assist in cooling the avionics at high altitudes where there is little air to dissipate heat. During 2000, more than 65,000 solar cells in 1,800 groups were mounted on the upper surface of Helios' wing. Produced by SunPower, Inc., these bi-facial silicon cells are about 19 percent efficient in the flight regime in which the helios is designed to operate, converting about 19 percent of the solar energy they receive into electrical current. The entire array is capable of producing a maximum output of about 35 kw at high noon on a summer day. The mission to reach and sustain flight at 100,000 feet in 2001 requires use of all 14 motors and minimal ballast to save weight, with the aircraft weighing in at only a little more than 1,600 lbs. The four-day mission above 50,000 feet envisioned for the Helios Prototype in 2003will see only eight motors powering the craft and the addition of the regenerative energy storage system now in development. The system will increase the Helios Prototype's flight weight to a little over 2,000 lbs. Fewer motors are needed for the long-endurance mission due to the lesser altitude requirements, and the excess electrical energy generated by the solar arrays during the daytime will be diverted to the hydrogen-oxygen fuel cell energy storage system, which will release the electricity to power the Helios after dark. With other system reliability improvements, production versions of the Helios are expected to fly missions lasting months at a time, becoming true 'atmospheric satellites.'

The Helios Prototype aircraft during initial climb-out to the west over the Pacific Ocean.

NASA Technical Reports Server (NTRS)

2001-01-01

As a follow-on to the Centurion (and earlier Pathfinder and Pathfinder-Plus) aircraft, the solar-powered Helios Prototype is the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions in the stratosphere. Developed by AeroVironment, Inc., of Monrovia, California, under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project, the unique craft is intended to demonstrate two key missions: the ability to reach and sustain horizontal flight at 100,000 feet altitude on a single-day flight in 2001, and to maintain flight above 50,000 feet altitude for at least four days in 2003, with the aid of a regenerative fuel cell-based energy storage system now in development. Both of these missions will be powered by electricity derived from non-polluting solar energy. The Helios Prototype is an enlarged version of the Centurion flying wing, which flew a series of test flights at NASA's Dryden Flight Research Center in late 1998. The craft has a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of its solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. The remotely piloted, electrically powered Helios Prototype went aloft on its maiden low-altitude checkout flight Sept. 8, 1999, over Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center in the Southern California desert. The initial flight series was flown on battery power as a risk-reduction measure. In all, six flights were flown in the Helios Protoype's initial development series. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved aerodynamic efficiency, allowing the Helios Prototype to fly higher, longer and with a larger payload than the smaller craft. In addition, project engineers added a differential Global Positioning Satellite (GPS) system to improve navigation, an extensive turbulence monitoring system payload to record structural loads on the aircraft both in the air and on the ground, and radiator plates to assist in cooling the avionics at high altitudes where there is little air to dissipate heat. During 2000, more than 65,000 solar cells in 1,800 groups were mounted on the upper surface of Helios' wing. Produced by SunPower, Inc., these bi-facial silicon cells are about 19 percent efficient in the flight regime in which the helios is designed to operate, converting about 19 percent of the solar energy they receive into electrical current. The entire array is capable of producing a maximum output of about 35 kw at high noon on a summer day. The mission to reach and sustain flight at 100,000 feet in 2001 requires use of all 14 motors and minimal ballast to save weight, with the aircraft weighing in at only a little more than 1,600 lbs. The four-day mission above 50,000 feet envisioned for the Helios Prototype in 2003will see only eight motors powering the craft and the addition of the regenerative energy storage system now in development. The system will increase the Helios Prototype's flight weight to a little over 2,000 lbs. Fewer motors are needed for the long-endurance mission due to the lesser altitude requirements, and the excess electrical energy generated by the solar arrays during the daytime will be diverted to the hydrogen-oxygen fuel cell energy storage system, which will release the electricity to power the Helios after dark. With other system reliability improvements, production versions of the Helios are expected to fly missions lasting months at a time, becoming true 'atmospheric satellites.'

The Helios Prototype aircraft in a northerly climb over Niihau Island, Hawaii, at about 8,000 feet a

NASA Technical Reports Server (NTRS)

2001-01-01

As a follow-on to the Centurion (and earlier Pathfinder and Pathfinder-Plus) aircraft, the solar-powered Helios Prototype is the latest and largest example of a slow-flying ultralight flying wing designed for long-duration, high-altitude Earth science or telecommunications relay missions in the stratosphere. Developed by AeroVironment, Inc., of Monrovia, California, under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project, the unique craft is intended to demonstrate two key missions: the ability to reach and sustain horizontal flight at 100,000 feet altitude on a single-day flight in 2001, and to maintain flight above 50,000 feet altitude for at least four days in 2003, with the aid of a regenerative fuel cell-based energy storage system now in development. Both of these missions will be powered by electricity derived from non-polluting solar energy. The Helios Prototype is an enlarged version of the Centurion flying wing, which flew a series of test flights at NASA's Dryden Flight Research Center in late 1998. The craft has a wingspan of 247 feet, 41 feet greater than the Centurion, 2 1/2 times that of its solar-powered Pathfinder flying wing, and longer than the wingspans of either the Boeing 747 jetliner or Lockheed C-5 transport aircraft. The remotely piloted, electrically powered Helios Prototype went aloft on its maiden low-altitude checkout flight Sept. 8, 1999, over Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center in the Southern California desert. The initial flight series was flown on battery power as a risk-reduction measure. In all, six flights were flown in the Helios Protoype's initial development series. In upgrading the Centurion to the Helios Prototype configuration, AeroVironment added a sixth wing section and a fifth landing gear pod, among other improvements. The additional wingspan increased the area available for installation of solar cells and improved aerodynamic efficiency, allowing the Helios Prototype to fly higher, longer and with a larger payload than the smaller craft. In addition, project engineers added a differential Global Positioning Satellite (GPS) system to improve navigation, an extensive turbulence monitoring system payload to record structural loads on the aircraft both in the air and on the ground, and radiator plates to assist in cooling the avionics at high altitudes where there is little air to dissipate heat. During 2000, more than 65,000 solar cells in 1,800 groups were mounted on the upper surface of Helios' wing. Produced by SunPower, Inc., these bi-facial silicon cells are about 19 percent efficient in the flight regime in which the helios is designed to operate, converting about 19 percent of the solar energy they receive into electrical current. The entire array is capable of producing a maximum output of about 35 kw at high noon on a summer day. The mission to reach and sustain flight at 100,000 feet in 2001 requires use of all 14 motors and minimal ballast to save weight, with the aircraft weighing in at only a little more than 1,600 lbs. The four-day mission above 50,000 feet envisioned for the Helios Prototype in 2003will see only eight motors powering the craft and the addition of the regenerative energy storage system now in development. The system will increase the Helios Prototype's flight weight to a little over 2,000 lbs. Fewer motors are needed for the long-endurance mission due to the lesser altitude requirements, and the excess electrical energy generated by the solar arrays during the daytime will be diverted to the hydrogen-oxygen fuel cell energy storage system, which will release the electricity to power the Helios after dark. With other system reliability improvements, production versions of the Helios are expected to fly missions lasting months at a time, becoming true 'atmospheric satellites.'

Large-Scale Boundary-Layer Control Tests on Two Wings in the NACA 20-Foot Wind Tunnel, Special Report

NASA Technical Reports Server (NTRS)

Freeman, Hugh B.

1935-01-01

Tests were made in the N.A.C.A. 20-foot wind tunnel on: (1) a wing, of 6.5-foot span, 5.5-foot chord, and 30 percent maximum thickness, fitted with large end plates and (2) a 16-foot span 2.67-foot chord wing of 15 percent maximum thickness to determine the increase in lift obtainable by removing the boundary layer and the power required for the blower. The results of the tests on the stub wing appeared more favorable than previous small-scale tests and indicated that: (1) the suction method was considerably superior to the pressure method, (2) single slots were more effective than multiple slots (where the same pressure was applied to all slots), the slot efficiency increased rapidly for increasing slot widths up to 2 percent of the wing chord and remained practically constant for all larger widths tested, (3) suction pressure and power requirements were quite low (a computation for a light airplane showed that a lift coefficient of 3.0 could be obtained with a suction as low as 2.3 times the dynamic pressure and a power expenditure less than 3 percent of the rated engine power), and (4) the volume of air required to be drawn off was quite high (approximately 0.5 cubic feet per second per unit wing area for an airplane landing at 40 miles per hour with a lift coefficient of 3,0), indicating that considerable duct area must be provided in order to prevent flow losses inside the wing and insure uniform distribution of suction along the span. The results from the tests of the large-span wing were less favorable than those on the stub wing. The reasons for this were, probably: (1) the uneven distribution of suction along the span, (2) the flow losses inside the wing, (3) the small radius of curvature of the leading edge of the wing section, and (4) the low Reynolds Number of these tests, which was about one half that of the stub wing. The results showed a large increase in the maximum lift coefficient with an increase in Reynolds Number in the range of the tests. The results of drag tests showed that the profile drag of the wing was reduced and the L/D ratio was increased throughout the range of lift coefficients corresponding to take-off and climb but that the minimum drag was increased. The slot arrangement that is best for low drag is not the same, however, as that for maximum lift.

F-8 SCW in flight

NASA Technical Reports Server (NTRS)

1973-01-01

A Vought F-8A Crusader was selected by NASA as the testbed aircraft (designated TF-8A) to install an experimental Supercritical Wing in place of the conventional wing. The unique design of the Supercritical Wing (SCW) reduces the effect of shock waves on the upper surface near Mach 1, which in turn reduces drag. In this photograph a Vought F-8A Crusader is shown being used as a flying testbed for an experimental Supercritical Wing airfoil. The smooth fairing of the fiberglass glove with the wing is illustrated in this view. This is the configuration of the F-8 SCW aircraft late in the program. The SCW team fitted the fuselage with bulges fore and aft of the wings. This was similar to the proposed shape of a near-sonic airliner. Both the SCW airfoil and the bulged-fuselage design were optimal for cruise at Mach 0.98. Dr. Whitcomb (designer of the SCW) had previously spent about four years working on supersonic transport designs. He concluded that these were impractical due to their high operating costs. The high drag at speeds above Mach 1 resulted in greatly increased costs. Following the fuel-price rises caused by the October 1973 oil embargo, airlines lost interest in near-sonic transports. Rather, they wanted a design that would have lower fuel consumption. Dr. Whitcomb developed a modified supercritical-wing shape that provided higher lift-to-drag ratios at the same speeds. He did this by using thicker airfoil sections and a reduced wing sweepback. This resulted in an increased aspect ratio without an increase in wing weight. In the three decades since the F-8 SCW flew, the use of such airfoils has become common. The F-8 Supercritical Wing was a flight research project designed to test a new wing concept designed by Dr. Richard Whitcomb, chief of the Transonic Aerodynamics Branch, Langley Research Center, Hampton, Virginia. Compared to a conventional wing, the supercritical wing (SCW) is flatter on the top and rounder on the bottom with a downward curve at the trailing edge. The Supercritical Wing was designed to delay the formation of and reduce the shock wave over the wing just below and above the speed of sound (transonic region of flight). Delaying the shock wave at these speeds results in less drag. Results of the NASA flight research at the Flight Research Center, Edwards, California, (later renamed the Dryden Flight Research Center) demonstrated that aircraft using the supercritical wing concept would have increased cruising speed, improved fuel efficiency, and greater flight range than those using conventional wings. As a result, supercritical wings are now commonplace on virtually every modern subsonic commercial transport. Results of the NASA project showed the SCW had increased the transonic efficiency of the F-8 as much as 15 percent and proved that passenger transports with supercritical wings, versus conventional wings, could save $78 million (in 1974 dollars) per year for a fleet of 280 200-passenger airliners. The F-8 Supercritical Wing (SCW) project flew from 1970 to 1973. Dryden engineer John McTigue was the first SCW program manager and Tom McMurtry was the lead project pilot. The first SCW flight took place on March 9, 1971. The last flight of the Supercritical wing was on May 23, 1973, with Ron Gerdes at the controls. Original wingspan of the F-8 is 35 feet, 2 inches while the wingspan with the supercritical wing was 43 feet, 1 inch. F-8 aircraft were powered by Pratt & Whitney J57 turbojet engines. The TF-8A Crusader was made available to the NASA Flight Research Center by the U.S. Navy. F-8 jet aircraft were built, originally, by LTV Aerospace, Dallas, Texas. Rockwell International's North American Aircraft Division received a $1.8 million contract to fabricate the supercritical wing, which was delivered to NASA in December 1969.

An investigation of the effects of the propeller slipstream of a laminar wing boundary layer

NASA Technical Reports Server (NTRS)

Howard, R. M.; Miley, S. J.; Holmes, B. J.

1985-01-01

A research program is in progress to study the effects of the propeller slipstream on natural laminar flow. Flight and wind tunnel measurements of the wing boundary layer have been made using hot-film velocity sensor probes. The results show the boundary layer, at any given point, to alternate between laminar and turbulent states. This cyclic behavior is due to periodic external flow turbulence originating from the viscous wake of the propeller blades. Analytic studies show the cyclic laminar/turbulent boundary layer to result in a significantly lower wing section drag than a fully turbulent boundary layer. The application of natural laminar flow design philosophy yields drag reduction benefits in the slipstream affected regions of the airframe, as well as the unaffected regions.

Pressure data for four analytically defined arrow wings in supersonic flow. [Langley Unitary Plan Wind Tunnel tests

NASA Technical Reports Server (NTRS)

Townsend, J. C.

1980-01-01

In order to provide experimental data for comparison with newly developed finite difference methods for computing supersonic flows over aircraft configurations, wind tunnel tests were conducted on four arrow wing models. The models were machined under numeric control to precisely duplicate analytically defined shapes. They were heavily instrumented with pressure orifices at several cross sections ahead of and in the region where there is a gap between the body and the wing trailing edge. The test Mach numbers were 2.36, 2.96, and 4.63. Tabulated pressure data for the complete test series are presented along with selected oil flow photographs. Comparisons of some preliminary numerical results at zero angle of attack show good to excellent agreement with the experimental pressure distributions.

Test Cases for a Rectangular Supercritical Wing Undergoing Pitching Oscillations

NASA Technical Reports Server (NTRS)

Bennett, Robert M.

2000-01-01

Steady and unsteady measured pressures for a Rectangular Supercritical Wing (RSW) undergoing pitching oscillations have been presented. From the several hundred compiled data points, 27 static and 36 pitching oscillation cases have been proposed for computational Test Cases to illustrate the trends with Mach number, reduced frequency, and angle of attack. The wing was designed to be a simple configuration for Computational Fluid Dynamics (CFD) comparisons. The wing had an unswept rectangular planform plus a tip of revolution, a panel aspect ratio of 2.0, a twelve per cent thick supercritical airfoil section, and no twist. The model was tested over a wide range of Mach numbers, from 0.27 to 0.90, corresponding to low subsonic flows up to strong transonic flows. The higher Mach numbers are well beyond the design Mach number such as might be required for flutter verification beyond cruise conditions. The pitching oscillations covered a broad range of reduced frequencies. Some early calculations for this wing are given for lifting pressure as calculated from a linear lifting surface program and from a transonic small perturbation program. The unsteady results were given primarily for a mild transonic condition at M = 0.70. For these cases the agreement with the data was only fair, possibly resulting from the omission of viscous effects. Supercritical airfoil sections are known to be sensitive to viscous effects (for example, one case cited). Calculations using a higher level code with the full potential equations have been presented for one of the same cases, and with the Euler equations. The agreement around the leading edge was improved, but overall the agreement was not completely satisfactory. Typically for low-aspect-ratio rectangular wings, transonic shock waves on the wing tend to sweep forward from root to tip such that there are strong three-dimensional effects. It might also be noted that for most of the test, the model was tested with free transition, but a few points were taken with an added transition strip for comparison. Some unpublished results of a rigid wing of the same airfoil and planform that was tested on the pitch and plunge apparatus mount system (PAPA) showed effects of the lower surface transition Strip on flutter at the lower subsonic Mach numbers. Significant effects of a transition strip were also obtained on a wing with a thicker supercritical section on the PAPA mount system. Both of these flutter tests on the PAPA resulted in very low reduced frequencies that may be a factor in this influence of the transition strip. However, these results indicate that correlation studies for RSW may require some attention to the estimation of transition location to accurately treat viscous effects. In this report several Test Cases are selected to illustrate trends for a variety of different conditions with emphasis on transonic flow effects. An overview of the model and tests is given and the standard formulary for these data is listed. Sample data points are presented in both tabular and graphical form. A complete tabulation and plotting of all the Test Cases is given. Only the static pressures and the real and imaginary parts of the first harmonic of the unsteady pressures are available. All the data for the test are available in electronic file form. The Test Cases are also available as separate electronic files.

New methodologies for calculation of flight parameters on reduced scale wings models in wind tunnel =

NASA Astrophysics Data System (ADS)

Ben Mosbah, Abdallah

In order to improve the qualities of wind tunnel tests, and the tools used to perform aerodynamic tests on aircraft wings in the wind tunnel, new methodologies were developed and tested on rigid and flexible wings models. A flexible wing concept is consists in replacing a portion (lower and/or upper) of the skin with another flexible portion whose shape can be changed using an actuation system installed inside of the wing. The main purpose of this concept is to improve the aerodynamic performance of the aircraft, and especially to reduce the fuel consumption of the airplane. Numerical and experimental analyses were conducted to develop and test the methodologies proposed in this thesis. To control the flow inside the test sections of the Price-Paidoussis wind tunnel of LARCASE, numerical and experimental analyses were performed. Computational fluid dynamics calculations have been made in order to obtain a database used to develop a new hybrid methodology for wind tunnel calibration. This approach allows controlling the flow in the test section of the Price-Paidoussis wind tunnel. For the fast determination of aerodynamic parameters, new hybrid methodologies were proposed. These methodologies were used to control flight parameters by the calculation of the drag, lift and pitching moment coefficients and by the calculation of the pressure distribution around an airfoil. These aerodynamic coefficients were calculated from the known airflow conditions such as angles of attack, the mach and the Reynolds numbers. In order to modify the shape of the wing skin, electric actuators were installed inside the wing to get the desired shape. These deformations provide optimal profiles according to different flight conditions in order to reduce the fuel consumption. A controller based on neural networks was implemented to obtain desired displacement actuators. A metaheuristic algorithm was used in hybridization with neural networks, and support vector machine approaches and their combination was optimized, and very good results were obtained in a reduced computing time. The validation of the obtained results has been made using numerical data obtained by the XFoil code, and also by the Fluent code. The results obtained using the methodologies presented in this thesis have been validated with experimental data obtained using the subsonic Price-Paidoussis blow down wind tunnel.

Dynamics and control of robotic aircraft with articulated wings

NASA Astrophysics Data System (ADS)

Paranjape, Aditya Avinash

There is a considerable interest in developing robotic aircraft, inspired by birds, for a variety of missions covering reconnaissance and surveillance. Flapping wing aircraft concepts have been put forth in light of the efficiency of flapping flight at small scales. These aircraft are naturally equipped with the ability to rotate their wings about the root, a form of wing articulation. This thesis covers some problems concerning the performance, stability and control of robotic aircraft with articulated wings in gliding flight. Specifically, we are interested in aircraft without a vertical tail, which would then use wing articulation for longitudinal as well as lateral-directional control. Although the dynamics and control of articulated wing aircraft share several common features with conventional fixed wing aircraft, the presence of wing articulation presents several unique benefits as well as limitations from the perspective of performance and control. One of the objective of this thesis is to understand these features using a combination of theoretical and numerical tools. The aircraft concept envisioned in this thesis uses the wing dihedral angles for longitudinal and lateral-directional control. Aircraft with flexible articulated wings are also investigated. We derive a complete nonlinear model of the flight dynamics incorporating dynamic CG location and the changing moment of inertia. We show that symmetric dihedral configuration, along with a conventional horizontal tail, can be used to control flight speed and flight path angle independently of each other. This characteristic is very useful for initiating an efficient perching maneuver. It is shown that wing dihedral angles alone can effectively regulate sideslip during rapid turns and generate a wide range of equilibrium turn rates while maintaining a constant flight speed and regulating sideslip. We compute the turning performance limitations that arise due to the use of wing dihedral for yaw control, and compare the steady state performance of rigid and flexible-winged aircraft. We present an intuitive but very useful notion, called the effective dihedral, which allows us to extend some of the stability and performance results derived for rigid aircraft to flexible aircraft. In the process, we identify the extent of flexibility needed to induce substantial performance benefits, and conversely the extent to which results derived for rigid aircraft apply to a flexible aircraft. We demonstrate, interestingly enough, that wing flexibility actually causes a deterioration in the maximum achievable turn rate when the sideslip is regulated. We also present experimental results which help demonstrate the capability of wing dihedral for control and for executing maneuvers such as slow, rapid descent and perching. Open loop as well as closed loop experiments are performed to demonstrate (a) the effectiveness of symmetric dihedral for flight path angle control, (b) yaw control using asymmetric dihedral, and (c) the elements of perching. Using a simple order of magnitude analysis, we derive conditions under which the wing is structurally statically stable, as well as conditions under which there exists time scale separation between the bending and twisting dynamics. We show that the time scale separation depends on the geometry of the wing cross section, the Poisson's ratio of the wing material, the flight speed and the aspect ratio of the wing. We design independent control laws for bending and twisting. A key contribution of this thesis is the formulation of a partial differential equation (PDE) boundary control problem for wing deformation. PDE-backstepping is used to derive tracking and exponentially stabilizing boundary control laws for wing twist which ensure that a weighted integral of the wing twist (net lift or the rolling moment) tracks the desired time-varying reference input. We show that a control law which only ensures tracking of a weighted integral improves the stability margin of the twisting dynamics sixteen fold. A tracking control law is derived for the wing tip displacement which uses motion planning and a novel two-stage perturbation observer. This work on PDE-based control of wing deformation allows for the use of highly flexible wings on MAVs. Put together, the thesis provides a comprehensive understanding of the flight dynamics of a robotic aircraft equipped with articulated wings, and provides a set of control laws for performing agile maneuvers and for honing the benefits of using highly flexible wings.

OBLIQUE VIEW OF ONE AND TWO STORY SECTIONS OF SOUTHWEST ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

OBLIQUE VIEW OF ONE AND TWO STORY SECTIONS OF SOUTHWEST WING OF THE RECREATION CENTER WITH GRADUATED SCALE IN 1' INCREMENTS. VIEW FACING NORTHEAST - U.S. Naval Base, Pearl Harbor, Bloch Recreation Center & Arena, Between Center Drive & North Road near Nimitz Gate, Pearl City, Honolulu County, HI

The Politics of Theocracy: Public Schools under Attack.

ERIC Educational Resources Information Center

Bauer, Norman J.

This paper examines the rhetoric and consequences of extreme religious right-wing groups' attack on American public schools. The first section identifies two competing world perspectives, the modern and postmodern perspectives. The second section identifies the fundamental principle that enables the two competing perspectives to coexist: the First…

Flight Measurement of Wall-Pressure Fluctuations and Boundary-Layer Turbulence

NASA Technical Reports Server (NTRS)

Mull, Harold R.; Algranti, Joseph S.

1960-01-01

The results are presented for a flight test program using a fighter type jet aircraft flying at pressure altitudes of 10,000, 20,000, and 30,000 feet at Mach numbers from 0.3 to 0.8. Specially designed apparatus was used to measure and record the output of microphones and hot-wire anemometers mounted on the forward-fuselage section and wing of the airplane. Mean-velocity profiles in the boundary layers were obtained from total-pressure measurements. The ratio of the root-mean-square fluctuating wall pressure to the free-stream dynamic pressure is presented as a function of Reynolds number and Mach number. The longitudinal component of the turbulent-velocity fluctuations was measured, and the turbulence-intensity profiles are presented for the wing and forward-fuselage section. In general, the results are in agreement with wind-tunnel measurements which have been-reported in the literature. For example, the variation the square root of p(sup 2)/q times the square root of p(sup 2) is the root mean square of the wall-pressure fluctuation, and q is the free-stream dynamic pressure) with Reynolds number was found to be essentially constant for the forward-fuselage-section boundary layer, while variations at the wing station were probably unduly affected by the microphone diameter (5/8 in.), which was large compared with the boundary-layer thickness.

Experimental Study of the Structure of a Wingtip Vortex

NASA Technical Reports Server (NTRS)

Anderson, Elgin A.; Wright, Christopher T.

2000-01-01

A complete look at the near-field development and subsequent role-up of a wingtip vortex from a NACA 0015 wing section is investigated. Two separate but equally important surveys of the vortex structure in the region adjacent to the wingtip and approximately one chord length downstream of the trailing edge are performed. The two surveys provide qualitative flow-visualization an quantitative velocity measurement data. The near-field development and subsequent role-up of the vortex structures is strongly influenced by the angle-of-attack and the end-cap treatment of the wing section. The velocity field near the wingtip of the NACA 0015 wing section was measured with a triple-sensor hot wire probe and compared to flow visualization images produced with titanium tetrachloride smoke injection and laser illumination. The flat end-cap results indicate the formation of multiple, relatively strong vortex structures as opposed to the formation of a single vortex produced with the round end-cap. The multiple vortices generated by the flat end-cap are seen to rotate around a common ce te in a helical pattern until they eventually merge into a single vortex. Compared to a non-dimensional loading parameter, the results of the velocity and flow visualization data shows a "jetlike" axial velocity profile for loading parameter values on the order of 0.1 and a "wakelike" profile for much lower loading parameter values.

Path planning and Ground Control Station simulator for UAV

NASA Astrophysics Data System (ADS)

Ajami, A.; Balmat, J.; Gauthier, J.-P.; Maillot, T.

In this paper we present a Universal and Interoperable Ground Control Station (UIGCS) simulator for fixed and rotary wing Unmanned Aerial Vehicles (UAVs), and all types of payloads. One of the major constraints is to operate and manage multiple legacy and future UAVs, taking into account the compliance with NATO Combined/Joint Services Operational Environment (STANAG 4586). Another purpose of the station is to assign the UAV a certain degree of autonomy, via autonomous planification/replanification strategies. The paper is organized as follows. In Section 2, we describe the non-linear models of the fixed and rotary wing UAVs that we use in the simulator. In Section 3, we describe the simulator architecture, which is based upon interacting modules programmed independently. This simulator is linked with an open source flight simulator, to simulate the video flow and the moving target in 3D. To conclude this part, we tackle briefly the problem of the Matlab/Simulink software connection (used to model the UAV's dynamic) with the simulation of the virtual environment. Section 5 deals with the control module of a flight path of the UAV. The control system is divided into four distinct hierarchical layers: flight path, navigation controller, autopilot and flight control surfaces controller. In the Section 6, we focus on the trajectory planification/replanification question for fixed wing UAV. Indeed, one of the goals of this work is to increase the autonomy of the UAV. We propose two types of algorithms, based upon 1) the methods of the tangent and 2) an original Lyapunov-type method. These algorithms allow either to join a fixed pattern or to track a moving target. Finally, Section 7 presents simulation results obtained on our simulator, concerning a rather complicated scenario of mission.

Present and Future Problems of Airplane Propulsion

NASA Technical Reports Server (NTRS)

Ackeret, J

1941-01-01

Some of the problems considered in this report include: thermodynamics of surface friction, application of thick wing sections, special applications of controllable propellers, and gas turbines for aircraft.

Ultrastructure of dragonfly wing veins: composite structure of fibrous material supplemented by resilin

PubMed Central

Appel, Esther; Heepe, Lars; Lin, Chung-Ping; Gorb, Stanislav N

2015-01-01

Dragonflies count among the most skilful of the flying insects. Their exceptional aerodynamic performance has been the subject of various studies. Morphological and kinematic investigations have showed that dragonfly wings, though being rather stiff, are able to undergo passive deformation during flight, thereby improving the aerodynamic performance. Resilin, a rubber-like protein, has been suggested to be a key component in insect wing flexibility and deformation in response to aerodynamic loads, and has been reported in various arthropod locomotor systems. It has already been found in wing vein joints, connecting longitudinal veins to cross veins, and was shown to endow the dragonfly wing with chordwise flexibility, thereby most likely influencing the dragonfly’s flight performance. The present study revealed that resilin is not only present in wing vein joints, but also in the internal cuticle layers of veins in wings of Sympetrum vulgatum (SV) and Matrona basilaris basilaris (MBB). Combined with other structural features of wing veins, such as number and thickness of cuticle layers, material composition, and cross-sectional shape, resilin most probably has an effect on the vein′s material properties and the degree of elastic deformations. In order to elucidate the wing vein ultrastructure and the exact localisation of resilin in the internal layers of the vein cuticle, the approaches of bright-field light microscopy, wide-field fluorescence microscopy, confocal laser-scanning microscopy, scanning electron microscopy and transmission electron microscopy were combined. Wing veins were shown to consist of up to six different cuticle layers and a single row of underlying epidermal cells. In wing veins of MBB, the latter are densely packed with light-scattering spheres, previously shown to produce structural colours in the form of quasiordered arrays. Longitudinal and cross veins differ significantly in relative thickness of exo- and endocuticle, with cross veins showing a much thicker exocuticle. The presence of resilin in the unsclerotised endocuticle suggests its contribution to an increased energy storage and material flexibility, thus to the prevention of vein damage. This is especially important in the highly stressed longitudinal veins, which have much lower possibility to yield to applied loads with the aid of vein joints, as the cross veins do. These results may be relevant not only for biologists, but may also contribute to optimise the design of micro-air vehicles. PMID:26352411

Measuring the ambiguity tolerance of medical students: a cross-sectional study from the first to sixth academic years

PubMed Central

2014-01-01

Background Tolerance of ambiguity, or the extent to which ambiguous situations are perceived as desirable, is an important component of the attitudes and behaviors of medical students. However, few studies have compared this trait across the years of medical school. General practitioners are considered to have a higher ambiguity tolerance than specialists. We compared ambiguity tolerance between general practitioners and medical students. Methods We designed a cross-sectional study to evaluate the ambiguity tolerance of 622 medical students in the first to sixth academic years. We compared this with the ambiguity tolerance of 30 general practitioners. We used the inventory for measuring ambiguity tolerance (IMA) developed by Reis (1997), which includes three measures of ambiguity tolerance: openness to new experiences, social conflicts, and perception of insoluble problems. Results We obtained a total of 564 complete data sets (return rate 90.1%) from medical students and 29 questionnaires (return rate 96.7%) from general practitioners. In relation to the reference groups defined by Reis (1997), medical students had poor ambiguity tolerance on all three scales. No differences were found between those in the first and the sixth academic years, although we did observe gender-specific differences in ambiguity tolerance. We found no differences in ambiguity tolerance between general practitioners and medical students. Conclusions The ambiguity tolerance of the students that we assessed was below average, and appeared to be stable throughout the course of their studies. In contrast to our expectations, the general practitioners did not have a higher level of ambiguity tolerance than the students did. PMID:24405525

Measuring the ambiguity tolerance of medical students: a cross-sectional study from the first to sixth academic years.

PubMed

Weissenstein, Anne; Ligges, Sandra; Brouwer, Britta; Marschall, Bernhard; Friederichs, Hendrik

2014-01-09

Tolerance of ambiguity, or the extent to which ambiguous situations are perceived as desirable, is an important component of the attitudes and behaviors of medical students. However, few studies have compared this trait across the years of medical school. General practitioners are considered to have a higher ambiguity tolerance than specialists. We compared ambiguity tolerance between general practitioners and medical students. We designed a cross-sectional study to evaluate the ambiguity tolerance of 622 medical students in the first to sixth academic years. We compared this with the ambiguity tolerance of 30 general practitioners. We used the inventory for measuring ambiguity tolerance (IMA) developed by Reis (1997), which includes three measures of ambiguity tolerance: openness to new experiences, social conflicts, and perception of insoluble problems. We obtained a total of 564 complete data sets (return rate 90.1%) from medical students and 29 questionnaires (return rate 96.7%) from general practitioners. In relation to the reference groups defined by Reis (1997), medical students had poor ambiguity tolerance on all three scales. No differences were found between those in the first and the sixth academic years, although we did observe gender-specific differences in ambiguity tolerance. We found no differences in ambiguity tolerance between general practitioners and medical students. The ambiguity tolerance of the students that we assessed was below average, and appeared to be stable throughout the course of their studies. In contrast to our expectations, the general practitioners did not have a higher level of ambiguity tolerance than the students did.

The air forces on a systematic series of biplane and triplane cellule models

NASA Technical Reports Server (NTRS)

Munk, Max M

1927-01-01

The air forces on a systematic series of biplane and triplane cellule models are the subject of this report. The test consist in the determination of the lift, drag, and moment of each individual airfoil in each cellule, mostly with the same wing section. The magnitude of the gap and of the stagger is systematically varied; not, however, the decalage, which is zero throughout the tests. Certain check tests with a second wing section make the tests more complete and conclusions more convincing. The results give evidence that the present army and navy specifications for the relative lifts of biplanes are good. They furnish material for improving such specifications for the relative lifts of triplanes. A larger number of factors can now be prescribed to take care of different cases.

Sex, Drugs and STDs: Preliminary Findings from the Belfast Youth Development Study

ERIC Educational Resources Information Center

McAloney, Kareena; McCrystal, Patrick; Percy, Andrew

2010-01-01

Young people's participation in sexual risk behaviours is commonly linked with participation in a range of other risky behaviours, and in particular with substance use behaviours. This cross-sectional analysis of the sixth sweep of the Belfast Youth Development Study aimed to examine associations between substance use and sexual activity and…

20 CFR 655.1116 - Element VI-What notification must facilities provide to registered nurses?

Code of Federal Regulations, 2010 CFR

2010-04-01

... provide to registered nurses? 655.1116 Section 655.1116 Employees' Benefits EMPLOYMENT AND TRAINING... Requirements Must a Facility Meet to Employ H-1C Nonimmigrant Workers as Registered Nurses? § 655.1116 Element VI—What notification must facilities provide to registered nurses? (a) The sixth attestation element...

20 CFR 655.1116 - Element VI-What notification must facilities provide to registered nurses?

Code of Federal Regulations, 2011 CFR

2011-04-01

... provide to registered nurses? 655.1116 Section 655.1116 Employees' Benefits EMPLOYMENT AND TRAINING... Requirements Must a Facility Meet to Employ H-1C Nonimmigrant Workers as Registered Nurses? § 655.1116 Element VI—What notification must facilities provide to registered nurses? (a) The sixth attestation element...

49 CFR 71.11 - Alaska zone.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Alaska zone. 71.11 Section 71.11 Transportation Office of the Secretary of Transportation STANDARD TIME ZONE BOUNDARIES § 71.11 Alaska zone. The sixth zone, the Alaska standard time zone, includes the entire State of Alaska, except as provided in § 71.12...

Language and Man: An Exploratory Foreign-Language Program for Grade Six.

ERIC Educational Resources Information Center

Bartos, Marilyn; And Others

This curriculum guide presents a program introducing sixth-grade children to the study of language, of languages other than English, and specifically of French. An initial section includes a variety of activities designed to interest students in the study of language, its peculiarties, complexities, and importance in life. Prior to the first…

Sherlock Holmes' Smarter Great-Granddaughter. Teacher's Guide.

ERIC Educational Resources Information Center

Kraft, D. Chetley; And Others

This teacher's manual is designed to accompany the sixth grade level of the kindergarten through grade six sequenced literature curriculum developed through the Instructional Television Services Section of the Nebraska Department of Education. The purpose of the series at this level is to introduce the student to the wide variety in types of…

Nuclear Technology. Course 28: Welding Inspection. Module 28-6, Process Controls.

ERIC Educational Resources Information Center

Espy, John

This sixth in a series of ten modules for a course titled Welding Inspection describes procedures review, process monitoring, and weld defect analysis. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject matter, (6)…

Student Preparation Workbook for the Multnomah Outdoor School. Revised Edition.

ERIC Educational Resources Information Center

Bohm, Rudy; Cole, Wally

Designed for sixth grade students to help them prepare for the Multnomah County (Oregon) Outdoor School experience, the workbook provides fundamental information about soil, water, plant, and animal resources. The workbook begins with an introduction to environmental manners (rules for working in the woods). A section devoted to each resource area…

Nuclear Power: The Fifth Horseman. Worldwatch Paper 6.

ERIC Educational Resources Information Center

Hayes, Denis

This publication is the sixth in a series of papers on global environmental issues. This paper evaluates the future of nuclear power, subjecting it to several tests: (1) economics; (2) safety; (3) adequacy of fuel supplies; (4) environmental impact; and (5) both national and international security. Section headings include: (1) The nuclear fuel…

Wind tunnel research comparing lateral control devices, particularly at high angles of attack XI : various floating tip ailerons on both rectangular and tapered wings

NASA Technical Reports Server (NTRS)

Weick, Fred E; Harris, Thomas A

1933-01-01

Discussed here are a series of systematic tests being conducted to compare different lateral control devices with particular reference to their effectiveness at high angles of attack. The present tests were made with six different forms of floating tip ailerons of symmetrical section. The tests showed the effect of the various ailerons on the general performance characteristics of the wing, and on the lateral controllability and stability characteristics. In addition, the hinge moments were measured for the most interesting cases. The results are compared with those for a rectangular wing with ordinary ailerons and also with those for a rectangular wing having full-chord floating tip ailerons. Practically all the floating tip ailerons gave satisfactory rolling moments at all angles of attack and at the same time gave no adverse yawing moments of appreciable magnitude. The general performance characteristics with the floating tip ailerons, however, were relatively poor, especially the rate of climb. None of the floating tip ailerons entirely eliminated the auto rotational moments at angles of attack above the stall, but all of them gave lower moments than a plain wing. Some of the floating ailerons fluttered if given sufficiently large deflection, but this could have been eliminated by moving the hinge axis of the ailerons forward. Considering all points including hinge moments, the floating tip ailerons on the wing with 5:1 taper are probably the best of those which were tested.

A computer program to calculate the longitudinal aerodynamic characteristics of wing-flap configurations with externally blown flaps

NASA Technical Reports Server (NTRS)

Mendenhall, M. R.; Goodwin, F. K.; Spangler, S. B.

1976-01-01

A vortex lattice lifting-surface method is used to model the wing and multiple flaps. Each lifting surface may be of arbitrary planform having camber and twist, and the multiple-slotted trailing-edge flap system may consist of up to ten flaps with different spans and deflection angles. The engine wakes model consists of a series of closely spaced vortex rings with circular or elliptic cross sections. The rings are normal to a wake centerline which is free to move vertically and laterally to accommodate the local flow field beneath the wing and flaps. The two potential flow models are used in an iterative fashion to calculate the wing-flap loading distribution including the influence of the waves from up to two turbofan engines on the semispan. The method is limited to the condition where the flow and geometry of the configurations are symmetric about the vertical plane containing the wing root chord. The calculation procedure starts with arbitrarily positioned wake centerlines and the iterative calculation continues until the total configuration loading converges within a prescribed tolerance. Program results include total configuration forces and moments, individual lifting-surface load distributions, including pressure distributions, individual flap hinge moments, and flow field calculation at arbitrary field points.

An Empirical Method Permitting Rapid Determination of the Area, Rate and Distribution of Water-Drop Impingement on an Airfoil of Arbitrary Section at Subsonic Speeds

NASA Technical Reports Server (NTRS)

Bergrun, N. R.

1951-01-01

An empirical method for the determination of the area, rate, and distribution of water-drop impingement on airfoils of arbitrary section is presented. The procedure represents an initial step toward the development of a method which is generally applicable in the design of thermal ice-prevention equipment for airplane wing and tail surfaces. Results given by the proposed empirical method are expected to be sufficiently accurate for the purpose of heated-wing design, and can be obtained from a few numerical computations once the velocity distribution over the airfoil has been determined. The empirical method presented for incompressible flow is based on results of extensive water-drop. trajectory computations for five airfoil cases which consisted of 15-percent-thick airfoils encompassing a moderate lift-coefficient range. The differential equations pertaining to the paths of the drops were solved by a differential analyzer. The method developed for incompressible flow is extended to the calculation of area and rate of impingement on straight wings in subsonic compressible flow to indicate the probable effects of compressibility for airfoils at low subsonic Mach numbers.

Are “armchair socialists” still sitting? Cross sectional study of political affiliation and physical activity

PubMed Central

Gale, Joanne; Milton, Karen

2014-01-01

Objective To examine the validity of the concept of left wing “armchair socialists” and whether they sit more and move less than their right wing and centrist counterparts. Design Secondary analysis of Eurobarometer data from 32 European countries. Setting The study emanated from the authors’ sit-stand desks (rather than from their armchairs). Participants Total of 29 193 European adults, of whom 1985 were left wing, 1902 right wing, 17 657 political centrists, and 7649 politically uncommitted. Main outcome measures Self-reported political affiliation, physical activity, and total daily sitting time. Methods Linear models were used to examine the relation between physical activity, sitting time, and reported political affiliation. Results The findings refute the existence of an “armchair socialist”; people at the extremes of both ends of the political spectrum were more physically active, with the right wing reporting 62.2 more weekly minutes of physical activity (95% confidence interval 23.9 to 100.5), and the left wing 57.8 more minutes (20.6 to 95.1) than those in the political centre. People with right wing political affiliations reported 12.8 minutes less time sitting a day (3.8 to 21.9) than the centrists. It is those sitting in the middle (politically) that are moving less, and possibly sitting more, both on the fence and elsewhere, making them a defined at-risk group. Conclusions There is little evidence to support the notion of armchair socialists, as they are more active than the mainstream in the political centre. Encouraging centrists to adopt stronger political views may be an innovative approach to increasing their physical activity, potentially benefiting population health. PMID:25500112

High-Lift Capability of Low Aspect Ratio Wings Utilizing Circulation Control and Upper Surface Blowing

DTIC Science & Technology

1980-07-01

span, ft (m) CD Drag coefficient, D/qS I CD Drag coefficient at zero lift CL Lift coefficient, L/qS CL Lift curve elope, aCL/aa I CL Maximum lift...recording on magnetic tape utilizing a Beckman 210 high-speed acquistion system. The wing-fuselage model was mounted in the test section such that...6, 7, and 8 show the tip sails have little impact on the zero or low-lift drag, but these j sails definitely influence the induced drag that is deve

Leeward flow over delta wings at supersonic speeds

NASA Technical Reports Server (NTRS)

Szodruch, J. G.

1980-01-01

A survey was made of the parameters affecting the development of the leeward symmetric separated flow over slender delta wings immersed in a supersonic stream. The parameters included Mach number, Reynolds number, angle of attack, leading-edge sweep angle, and body cross-sectional shape, such that subsonic and supersonic leading-edge flows are encountered. It was seen that the boundaries between the various flow regimes existing about the leeward surface may conveniently be represented on a diagram with the components of angle of attack and Mach number normal to the leading edge as governing parameters.

Development of a composite tailoring procedure for airplane wing

NASA Technical Reports Server (NTRS)

Chattopadhyay, Aditi; Zhang, Sen

1995-01-01

The development of a composite wing box section using a higher order-theory is proposed for accurate and efficient estimation of both static and dynamic responses. The theory includes the effect of through-the-thickness transverse shear deformations which is important in laminated composites and is ignored in the classical approach. The box beam analysis is integrated with an aeroelastic analysis to investigate the effect of composite tailoring using a formal design optimization technique. A hybrid optimization procedure is proposed for addressing both continuous and discrete design variables.

Thermostructural applications of heat pipes

NASA Technical Reports Server (NTRS)

Peeples, M. E.; Reeder, J. C.; Sontag, K. E.

1979-01-01

The feasibility of integrating heat pipes in high temperature structure to reduce local hot spot temperature was evaluated for a variety of hypersonic aerospace vehicles. From an initial list of twenty-two potential applications, the single stage to orbit wing leading edge showed the greatest promise and was selected for preliminary design of an integrated heat pipe thermostructural system. The design consisted of a Hastelloy X assembly with sodium heat pipe passages aligned normal to the wing leading edge. A d-shaped heat pipe cross section was determined to be optimum from the standpoint of structural weight.

Low-Speed Characteristics in Pitch of a 42 Degree Swept-Back Wing with Aspect Ratio 3.9 and Circular-Arc Airfoil Sections

DTIC Science & Technology

1947-11-13

requests shall be referred to National Aeronautics and Space Administration, Washington, DC. NACA Res. Abstracts no. 57 dtd 29 Jan 1954; NASA TR...viscosity Telocity of sound MODEL A sketch of the vine and fuselage Is presented in figure 1 and a photograph of the wing is shorn in ficure 2. The...is presented in figure 3 and a photograph of the leading-edge flap installations is given in figure U- The flaps were of constant chord and extended

Range Performance of Bombers Powered by Turbine-Propeller Power Plants

NASA Technical Reports Server (NTRS)

Cline, Charles W.

1950-01-01

Calculations have been made to find range? attainable by bombers of gross weights from l40,000 to 300,000 pounds powered by turbine-propeller power plants. Only conventional configurations were considered and emphasis was placed upon using data for structural and aerodynamic characteristics which are typical of modern military airplanes. An effort was made to limit the various parameters invoked in the airplane configuration to practical values. Therefore, extremely high wing loadings, large amounts of sweepback, and very high aspect ratios have not been considered. Power-plant performance was based upon the performance of a typical turbine-propeller engine equipped with propellers designed to maintain high efficiencies at high-subsonic speeds. Results indicated, in general, that the greatest range, for a given gross weight, is obtained by airplanes of high wing loading, unless the higher cruising speeds associated with the high-wing-loading airplanes require-the use of thinner wing sections. Further results showed the effect of cruising at-high speeds, of operation at very high altitudes, and of carrying large bomb loads.

Low Reynolds Number Aerodynamic Characteristics of Several Airplane Configurations Designed to Fly in the Mars Atmosphere at Subsonic Speeds

NASA Technical Reports Server (NTRS)

Re, Richard J.; Pendergraft, Odis C., Jr.; Campbell, Richard L.

2006-01-01

A 1/4-scale wind tunnel model of an airplane configuration developed for short duration flight at subsonic speeds in the Martian atmosphere has been tested in the Langley Research Center Transonic Dynamics Tunnel. The tunnel was pumped down to extremely low pressures to represent Martian Mach/Reynolds number conditions. Aerodynamic data were obtained and upper and lower surface wind pressures were measured at one spanwise station on some configurations. Three unswept wings of the same planform but different airfoil sections were tested. Horizontal tail incidence was varied as was the deflection of plain and split trailing-edge flaps. One unswept wing configuration was tested with the lower part of the fuselage removed and the vertical/horizontal tail assembly inverted and mounted from beneath the fuselage. A sweptback wing was also tested. Tests were conducted at Mach numbers from 0.50 to 0.90. Wing chord Reynolds number was varied from 40,000 to 100,000 and angles of attack and sideslip were varied from -10deg to 20deg and -10deg to 10deg, respectively.

Multidisciplinary design optimization of aircraft wing structures with aeroelastic and aeroservoelastic constraints

NASA Astrophysics Data System (ADS)

Jung, Sang-Young

Design procedures for aircraft wing structures with control surfaces are presented using multidisciplinary design optimization. Several disciplines such as stress analysis, structural vibration, aerodynamics, and controls are considered simultaneously and combined for design optimization. Vibration data and aerodynamic data including those in the transonic regime are calculated by existing codes. Flutter analyses are performed using those data. A flutter suppression method is studied using control laws in the closed-loop flutter equation. For the design optimization, optimization techniques such as approximation, design variable linking, temporary constraint deletion, and optimality criteria are used. Sensitivity derivatives of stresses and displacements for static loads, natural frequency, flutter characteristics, and control characteristics with respect to design variables are calculated for an approximate optimization. The objective function is the structural weight. The design variables are the section properties of the structural elements and the control gain factors. Existing multidisciplinary optimization codes (ASTROS* and MSC/NASTRAN) are used to perform single and multiple constraint optimizations of fully built up finite element wing structures. Three benchmark wing models are developed and/or modified for this purpose. The models are tested extensively.

Conceptual Design and Structural Analysis of an Open Rotor Hybrid Wing Body Aircraft

NASA Technical Reports Server (NTRS)

Gern, Frank H.

2013-01-01

Through a recent NASA contract, Boeing Research and Technology in Huntington Beach, CA developed and optimized a conceptual design of an open rotor hybrid wing body aircraft (HWB). Open rotor engines offer a significant potential for fuel burn savings over turbofan engines, while the HWB configuration potentially allows to offset noise penalties through possible engine shielding. Researchers at NASA Langley converted the Boeing design to a FLOPS model which will be used to develop take-off and landing trajectories for community noise analyses. The FLOPS model was calibrated using Boeing data and shows good agreement with the original Boeing design. To complement Boeing s detailed aerodynamics and propulsion airframe integration work, a newly developed and validated conceptual structural analysis and optimization tool was used for a conceptual loads analysis and structural weights estimate. Structural optimization and weight calculation are based on a Nastran finite element model of the primary HWB structure, featuring centerbody, mid section, outboard wing, and aft body. Results for flight loads, deformations, wing weight, and centerbody weight are presented and compared to Boeing and FLOPS analyses.

An experimental study of the vortex wake at Mach number of 3

NASA Astrophysics Data System (ADS)

Shmakov, A. S.; Shevchenko, A. M.

2017-10-01

The results of experimental study of the flow in the wing wake at Mach number of 3 are presented. These experiments extends the data obtained in the same experimental setup at Mach numbers of 2.5 and 4 [1]. Experiments were carried out in supersonic wind tunnel T-325 of ITAM SB RAS. Rectangular half-wing with sharp edges with a chord length of 30 mm and semispan of 95 mm was used to generate vortex wake. Experimental data were obtained in two cross sections located 1.5 and 6 chord length downstream of the trailing edge at wing angle of attack of 10 degrees. Constant temperature hot-wire anemometer was used to measure disturbances in supersonic flow. Hot-wire aemometer was made of a tungsten wire with a diameter of 10 µm and length of 1.5 mm. Shlieren flow visualization were performed. As a result, the position and size of the vortex core in the wake of a rectangular wing were determined. For the first time mass flow distribution and its pulsations in the supersonic longitudinal vortex was measured at Mach number of 3.

Multidisciplinary design integration system for a supersonic transport aircraft

NASA Technical Reports Server (NTRS)

Dovi, A. R.; Wrenn, G. A.; Barthelemy, J.-F. M.; Coen, P. G.; Hall, L. E.

1992-01-01

An aircraft preliminary design system which provides the multidisciplinary communications and couplings between several engineering disciplines is described. A primary benefit of this system is to demonstrate advanced technology multidisciplinary design integration methodologies. The current version includes the disciplines of aerodynamics and structures. Contributing engineering disciplines are coupled using the Global Sensitivity Equation approach to influence the global design optimization problem. A high speed civil transport configuration is used for configuration trade studies. Forty four independent design variables are used to control the cross-sectional areas of wing rib and spar caps and the thicknesses of wingskincover panels. A total of 300 stress, strain, buckling and displacement behavioral constraints and minimum gages on the design variables were used to optimize the idealized wing structure. The goal of the designs to resize the wing cover panels and internal structure for minimum mass.

AlGaAs diode pumped tunable chromium lasers

DOEpatents

Krupke, William F.; Payne, Stephen A.

1992-01-01

An all-solid-state laser system is disclosed wherein the laser is pumped in the longwave wing of the pump absorption band. By utilizing a laser material that will accept unusually high dopant concentrations without deleterious effects on the crystal lattice one is able to compensate for the decreased cross section in the wing of the absorption band, and the number of pump sources which can be used with such a material increases correspondingly. In a particular embodiment a chromium doped colquiriite-structure crystal such as Cr:LiSrAlF.sub.6 is the laser material. The invention avoids the problems associated with using AlGaInP diodes by doping the Cr:LiSrAlF.sub.6 heavily to enable efficient pumping in the longwave wing of the absorption band with more practical AlGaAs diodes.

Steady and unsteady transonic pressure measurements on a clipped delta wing for pitching and control-surface oscillations

NASA Technical Reports Server (NTRS)

Hess, Robert W.; Cazier, F. W., Jr.; Wynne, Eleanor C.

1986-01-01

Steady and unsteady pressures were measured on a clipped delta wing with a 6-percent circular-arc airfoil section and a leading-edge sweep angle of 50.40 deg. The model was oscillated in pitch and had an oscillating trailing-edge control surface. Measurements were concentrated over a Mach number range from 0.88 to 0.94; less extensive measurements were made at Mach numbers of 0.40, 0.96, and 1.12. The Reynolds number based on mean chord was approximately 10 x 10 to the 6th power. The interaction of wing or control-surface deflection with the formation of shock waves and with a leading-edge vortex generated complex pressure distributions that were sensitive to frequency and to small changes in Mach number at transonic speeds.

Experimental and Calculated Characteristics of Several NACA 44-series Wings with Aspect Ratios of 8, 10, and 12 and Taper Ratios of 2.5 and 3.5

NASA Technical Reports Server (NTRS)

Neely, Robert H; Bollech, Thomas V; Westrick, Gertrude C

1947-01-01

The aerodynamic characteristics of seven unswept tapered wings were determined by calculation from two-dimensional data and by wind-tunnel tests in order to demonstrate the accuracy of the calculations and to show some of the effects of aspect ratio, taper ratio, and root thickness-chord ratio. The characteristics were calculated by the usual application of the lifting-line theory which assumes linear section lift curves and also by an application of the theory which allows the use of nonlinear lift curves. A correction to the lift for the effect of chord was made by using the Jones edge-velocity factor. The wings had aspect ratios of 8, 10, and 12, taper ratios of 2.5 and 3.5, and NACA 44-series airfoils.

The aerodynamic analysis of the gyroplane rotating-wing system

NASA Technical Reports Server (NTRS)

Wheatley, John B

1934-01-01

An aerodynamic analysis of the gyroplane rotating-wing system is presented herein. This system consists of a freely rotating rotor in which opposite blades are rigidly connected and allowed to rotate or feather freely about their span axis. Equations have been derived for the lift, the lift-drag ratio, the angle of attack, the feathering angles, and the rolling and pitching moments of a gyroplane rotor in terms of its basic parameters. Curves of lift-drag ratio against lift coefficient have been calculated for a typical case, showing the effect of varying the pitch angle, the solidarity, and the average blade-section drag coefficient. The analysis expresses satisfactorily the qualitative relations between the rotor characteristics and the rotor parameters. As disclosed by this investigation, the aerodynamic principles of the gyroplane are sound, and further research on this wing system is justified.

Laser velocimeter systems analysis applied to a flow survey above a stalled wing. [conducted in Langley high-speed 7 by 10 foot tunnel

NASA Technical Reports Server (NTRS)

Young, W. H., Jr.; Meyers, J. F.; Hepner, T. E.

1977-01-01

A laser velocimeter operating in the backscatter mode was used to survey the flow above a stalled wing. Polarization was used to separate the two orthogonal velocity components of the fringe-type laser velocimeter, and digital counters were used for data processing. The velocities of the kerosene seed particles were measured with less than 2 percent uncertainty. The particle velocity measurements were collected into histograms. The flow field survey was carried out above an aspect-ratio-8 stalled wing with an NACA 0012 section. The angle of attack was 19.5 deg, the Mach number was 0.49, and the Reynolds number was 1,400,000. The flow field was characterized by the periodic shedding of discrete vortices from near the crest of the airfoil.

Kinetic Energy Distribution of D(2p) Atoms From Analysis of the D Lyman-a Line Profile

NASA Technical Reports Server (NTRS)

Ciocca, Marco; Ajello, Joseph M.; Liu, Xianming; Maki, Justin

1997-01-01

The absolute cross sections of the line center (slow atoms) and wings (fast atoms) and total emission line profile were measured from threshold to 400 eV. Analytical model coeffiecients are given for the energy dependence of the measured slow atom cross section.

Pushing Back the Origin of Bantu Lexicography: The Vocabularium Congense of 1652, 1928, 2012.

PubMed

De Kind, Jasper; de Schryver, Gilles-Maurice; Bostoen, Koen

2012-12-01

In this article, the oldest Bantu dictionary hitherto known is explored, that is the Vocabularium Latinum, Hispanicum, e Congense , handed down to us through a manuscript from 1652 by the Flemish Capuchin Joris van Gheel, missionary in the Kongo (present-day north-western Angola and the southern part of the Lower Congo Province of the DRC). The manuscript was heavily reworked by the Belgian Jesuits Joseph van Wing and Constant Penders, and published in 1928. Both works are currently being digitized, linked and added to an interlingual and multimedia database that revolves around Kikongo and the early history of the Kongo kingdom. In Sections 1 and 2 the origins of Bantu lexicography in general and of Kikongo metalexicography in particular are revisited. Sections 3 and 4 are devoted to a study of Van Gheel's manuscript and an analysis of Van Wing and Penders' rework. In Sections 5 and 6 translation equivalence and lexicographical structure in both dictionaries are scrutinized and compared. In Section 7, finally, all the material is brought together.

Pushing Back the Origin of Bantu Lexicography: The Vocabularium Congense of 1652, 1928, 2012

PubMed Central

De Kind, Jasper; de Schryver, Gilles-Maurice; Bostoen, Koen

2013-01-01

In this article, the oldest Bantu dictionary hitherto known is explored, that is the Vocabularium Latinum, Hispanicum, e Congense, handed down to us through a manuscript from 1652 by the Flemish Capuchin Joris van Gheel, missionary in the Kongo (present-day north-western Angola and the southern part of the Lower Congo Province of the DRC). The manuscript was heavily reworked by the Belgian Jesuits Joseph van Wing and Constant Penders, and published in 1928. Both works are currently being digitized, linked and added to an interlingual and multimedia database that revolves around Kikongo and the early history of the Kongo kingdom. In Sections 1 and 2 the origins of Bantu lexicography in general and of Kikongo metalexicography in particular are revisited. Sections 3 and 4 are devoted to a study of Van Gheel’s manuscript and an analysis of Van Wing and Penders’ rework. In Sections 5 and 6 translation equivalence and lexicographical structure in both dictionaries are scrutinized and compared. In Section 7, finally, all the material is brought together. PMID:23814547

Validation of morphing wing methodologies on an unmanned aerial system and a wind tunnel technology demonstrator

NASA Astrophysics Data System (ADS)

Gabor, Oliviu Sugar

To increase the aerodynamic efficiency of aircraft, in order to reduce the fuel consumption, a novel morphing wing concept has been developed. It consists in replacing a part of the wing upper and lower surfaces with a flexible skin whose shape can be modified using an actuation system placed inside the wing structure. Numerical studies in two and three dimensions were performed in order to determine the gains the morphing system achieves for the case of an Unmanned Aerial System and for a morphing technology demonstrator based on the wing tip of a transport aircraft. To obtain the optimal wing skin shapes in function of the flight condition, different global optimization algorithms were implemented, such as the Genetic Algorithm and the Artificial Bee Colony Algorithm. To reduce calculation times, a hybrid method was created by coupling the population-based algorithm with a fast, gradient-based local search method. Validations were performed with commercial state-of-the-art optimization tools and demonstrated the efficiency of the proposed methods. For accurately determining the aerodynamic characteristics of the morphing wing, two new methods were developed, a nonlinear lifting line method and a nonlinear vortex lattice method. Both use strip analysis of the span-wise wing section to account for the airfoil shape modifications induced by the flexible skin, and can provide accurate results for the wing drag coefficient. The methods do not require the generation of a complex mesh around the wing and are suitable for coupling with optimization algorithms due to the computational time several orders of magnitude smaller than traditional three-dimensional Computational Fluid Dynamics methods. Two-dimensional and three-dimensional optimizations of the Unmanned Aerial System wing equipped with the morphing skin were performed, with the objective of improving its performances for an extended range of flight conditions. The chordwise positions of the internal actuators, the spanwise number of actuation stations as well as the displacement limits were established. The performance improvements obtained and the limitations of the morphing wing concept were studied. To verify the optimization results, high-fidelity Computational Fluid Dynamics simulations were also performed, giving very accurate indications of the obtained gains. For the morphing model based on an aircraft wing tip, the skin shapes were optimized in order to control laminar flow on the upper surface. An automated structured mesh generation procedure was developed and implemented. To accurately capture the shape of the skin, a precision scanning procedure was done and its results were included in the numerical model. High-fidelity simulations were performed to determine the upper surface transition region and the numerical results were validated using experimental wind tunnel data.

The effect of wind tunnel wall interference on the performance of a fan-in-wing VTOL model

NASA Technical Reports Server (NTRS)

Heyson, H. H.

1974-01-01

A fan-in-wing model with a 1.07-meter span was tested in seven different test sections with cross-sectional areas ranging from 2.2 sq meters to 265 sq meters. The data from the different test sections are compared both with and without correction for wall interference. The results demonstrate that extreme care must be used in interpreting uncorrected VTOL data since the wall interference may be so large as to invalidate even trends in the data. The wall interference is particularly large at the tail, a result which is in agreement with recently published comparisons of flight and large scale wind tunnel data for a propeller-driven deflected-slipstream configuration. The data verify the wall-interference theory even under conditions of extreme interference. A method yields reasonable estimates for the onset of Rae's minimum-speed limit. The rules for choosing model sizes to produce negligible wall effects are considerably in error and permit the use of excessively large models.

3D surface reconstruction and visualization of the Drosophila wing imaginal disc at cellular resolution

NASA Astrophysics Data System (ADS)

Bai, Linge; Widmann, Thomas; Jülicher, Frank; Dahmann, Christian; Breen, David

2013-01-01

Quantifying and visualizing the shape of developing biological tissues provide information about the morphogenetic processes in multicellular organisms. The size and shape of biological tissues depend on the number, size, shape, and arrangement of the constituting cells. To better understand the mechanisms that guide tissues into their final shape, it is important to investigate the cellular arrangement within tissues. Here we present a data processing pipeline to generate 3D volumetric surface models of epithelial tissues, as well as geometric descriptions of the tissues' apical cell cross-sections. The data processing pipeline includes image acquisition, editing, processing and analysis, 2D cell mesh generation, 3D contourbased surface reconstruction, cell mesh projection, followed by geometric calculations and color-based visualization of morphological parameters. In their first utilization we have applied these procedures to construct a 3D volumetric surface model at cellular resolution of the wing imaginal disc of Drosophila melanogaster. The ultimate goal of the reported effort is to produce tools for the creation of detailed 3D geometric models of the individual cells in epithelial tissues. To date, 3D volumetric surface models of the whole wing imaginal disc have been created, and the apicolateral cell boundaries have been identified, allowing for the calculation and visualization of cell parameters, e.g. apical cross-sectional area of cells. The calculation and visualization of morphological parameters show position-dependent patterns of cell shape in the wing imaginal disc. Our procedures should offer a general data processing pipeline for the construction of 3D volumetric surface models of a wide variety of epithelial tissues.

Academic Stressors and Anxiety in Children: The Role of Paternal Support

ERIC Educational Resources Information Center

Leung, Grace S. M.; Yeung, K. C.; Wong, Daniel F. K.

2010-01-01

We examined the role of paternal support in the relation between academic stress and the mental health of primary school children in Hong Kong. The participants of this cross-sectional study were 1,171 fifth and sixth graders. The results indicated that academic stress was a risk factor that heightened student anxiety levels and that parental…

Improving the Spelling Ability among Speakers of African American English through Explicit Instruction

ERIC Educational Resources Information Center

Pittman, Ramona T.; Joshi, R. Malatesha; Carreker, Suzanne

2014-01-01

The purpose of this eight week study was to provide explicit instruction to improve spelling to 124 sixth grade students who are speakers of African American English (AAE). Two classroom teachers taught 14 different language arts class sections. The research design was a pretest/posttest/posttest design using wait-list-control. The treatment group…

Associations Between Tobacco Marketing and Use Among Urban Youth in India

ERIC Educational Resources Information Center

Arora, Monika; Reddy, K. Srinath; Stigler, Melissa H.; Perry, Cheryl L.

2008-01-01

Objectives: To study if receptivity and exposure to tobacco marketing are correlated with tobacco use and psychosocial risk factors for tobacco use among a sample of urban Indian youth. Methods: Analysis of cross-sectional survey data from Project MYTRI, a group randomized intervention trial, in Delhi and Chennai, India, collected from sixth and…

Resourcefulness: A Protective Factor Buffer against the Academic Stress of School-Aged Children

ERIC Educational Resources Information Center

Leung, Grace Suk Man; He, Xuesong

2010-01-01

The objectives of this study were twofold: to examine the interaction of academic stress and student resourcefulness on subject grades and to identify the factors of parental support that contribute to student resourcefulness. The participants of this cross-sectional study were 695 fifth and sixth graders from four major districts in Shanghai.…

What Is Shakespeare Doing in My Hut?: A-Level Literature and the Sierra Leonean Student.

ERIC Educational Resources Information Center

Wright, Handel K.

A study brought together literature appreciation, schema theory, and cross-cultural studies to explore the relationship between the backgrounds of students in one sixth-form literature class in Sierra Leone and the contexts of the plays described in the drama section of the "A" level literature syllabus of the West African Examinations…

Classroom Practices in Teaching English, 1968-1969: A Sixth Report of the NCTE Committee on Promising Practices.

ERIC Educational Resources Information Center

National Council of Teachers of English, Champaign, IL.

Twenty-five articles describing techniques for teaching English are organized under four headings: language, literature, composition, and miscellany. Included in the language section are discussions of an oral language program for 3- to 5-year-old disadvantaged children, of language development through creative dramatics, of a junior high school…

The 4M companY: Make Mine Metric Mission! Sixth Grade Teacher's Guide.

ERIC Educational Resources Information Center

Hawaii State Dept. of Education, Honolulu.

This is one of several teacher's guides for the 4M Company, a set of materials for teaching metric concepts and computation skills to elementary school students. Included in the guide are sections on needed materials, metric symbols, length, perimeter, area, volume, capacity, mass (weight), decimals, conversion between metric units, temperature,…

Australian Family Research Conference Proceedings (Canberra, Australia, November 23-25, 1983). Volume VI: Family Life.

ERIC Educational Resources Information Center

Institute of Family Studies, Melbourne (Australia).

Family life is the focus of this sixth volume in a series containing the proceedings of the 1983 Australian Family Research Conference. The papers are organized under two major sections: Children and Families and Family Environments. Papers and authors included are: "Family Conflict and Child Competence" (Gay Ochiltree and Paul Amato),…

Synthetic Organic Chemicals: United States Production and Sales, 1976.

ERIC Educational Resources Information Center

Adams, Roger; And Others

This is the sixth annual report of the U.S. Trade Commission on domestic production and sales of synthetic organic chemicals and the raw materials from which they are made. The report consists of 15 sections, each covering a specified group (based primarily on use) of organic chemicals as follows: tar and tar crudes; primary products from…

The Impact of Orthographic Connectivity on Visual Word Recognition in Arabic: A Cross-Sectional Study

ERIC Educational Resources Information Center

Khateb, Asaid; Khateb-Abdelgani, Manal; Taha, Haitham Y.; Ibrahim, Raphiq

2014-01-01

This study aimed at assessing the effects of letters' connectivity in Arabic on visual word recognition. For this purpose, reaction times (RTs) and accuracy scores were collected from ninety-third, sixth and ninth grade native Arabic speakers during a lexical decision task, using fully connected (Cw), partially connected (PCw) and…

Perceived Parental and Peer Disapproval toward Substances: Influences on Adolescent Decision-Making

ERIC Educational Resources Information Center

Sawyer, Thomas M.; Stevenson, John F.

2008-01-01

This study investigated the relative influence of perceived parent and peer disapproval for using drugs on youth intentions to use drugs. In a cross-sectional design, sixth and eighth grade students (N = 1,649) completed surveys that included measures of parent disapproval, peer disapproval, and intentions to use drugs in the future. Parent…

Every Day Lots of Ways. An Interdisciplinary Nutrition Curriculum for Kindergarten-Sixth Grade.

ERIC Educational Resources Information Center

Bagby, Robin; Campbell, V. Star; Achterberg, Cheryl; Probart, Claudia; Ebel, Kimberlyn

This K-6 interdisciplinary nutrition curriculum focuses on vegetables and fruits. The lessons use core subjects to promote consumption of fresh, frozen, and canned vegetables and fruits; vegetable and fruit juices; and dried fruits. The lessons also investigate the Food Guide Pyramid. Each lesson plan has a section entitled Extensions. The…

The Construction of Children's Character. Ninety-Sixth Yearbook of the National Society for the Study of Education. Part II.

ERIC Educational Resources Information Center

Molnar, Alex, Ed.

1997-01-01

This book presents a comprehensive and critical assessment of contemporary character education theory and practice from a variety of perspectives: historical, cultural, philosophical, psychological, empirical, political, and ethical. The essays in this book are divided into five sections intended to help develop a well-grounded understanding of…