Preliminary Flight Tests of the N.A.C.A. Roots Type Aircraft Engine Supercharger

NASA Technical Reports Server (NTRS)

Gardiner, Arthur W; Reid, Elliott G

1928-01-01

An investigation of the suitability of the N.A.C.A. Roots type aircraft engine supercharger to flight-operating conditions, as determined the effects of the use of the supercharger upon engine operation and airplane performance, is described in this report. Attention was concentrated on the operation of the engine-supercharger unit and on the improvement of climbing ability; some information concerning high speeds at altitude was obtained. The supercharger was found to be satisfactory under flight-operating conditions. Although two failures occurred during the tests, the causes of both were minor and have been eliminated. Careful examination of the engines revealed no detrimental effects which could be attributed to supercharging. Marked improvements in climbing ability and high speeds at altitude were effected. It was also found that the load which could be carried to a given moderate or high altitude in a fixed time was considerably augmented. A slight sacrifice of low-altitude performance was necessitated, however, by the use of a fixed-pitch propeller. From a consideration of the very satisfactory flight performance of the Roots supercharger and of its inherent advantages, it is concluded that this type is particularly attractive for use in certain classes of commercial airplanes and in a number of military types.

A restored NACA P-51D Mustang in flight

NASA Image and Video Library

2000-09-15

Bill Allmon of Las Vegas, Nevada, brought his restored NACA P-51D to a reunion of former NACA employees at the NASA Dryden Flight Research Center located at Edwards Air Force Base, Calif., on Sept. 15, 2000. Allmon's award-winning restoration is a genuine former NACA testbed that saw service at the Langley Research Center in Virginia in the late 1940s. Later this Mustang was put on outdoor static display as an Air National Guard monument in Pittsburgh, Pa., where exposure to the elements ravaged its metal structure, necessitating an extensive four-year rebuild.

D-558-1 on ramp with ground crew and NACA pilot Bob Champine

NASA Technical Reports Server (NTRS)

1949-01-01

NACA test pilot Robert Champine is seen in the cockpit of the Douglas D-558-1 Skystreak with the ground crew. Robert A. Champine was a research pilot with the National Advisory Committee for Aeronautics (NACA) and the National Aeronautics and Space Administration (NASA) from December 1947 to 1979, when he retired as Langley Research Center's senior research pilot. He began his career with the NACA at the Langley Memorial Aeronautical Laboratory in Hampton, Virginia (as Langley Research Center was then called). He transferred to the NACA's High-Speed Flight Research Station in the Mojave Desert of California in October 1948, where he flew the X-1 and D-558-1 and -2 research airplanes. On December 2, 1948, Bob became the 6th man and 3rd civilian to break the mysterious sound barrier. He exceeded Mach 1 on NACA flight 23 checking handling qualities and pressure distribution on the XS-1 #2, after having been dropped from the B-29 mother ship, above the Rogers Dry Lake in California. On August 4, 1949, NACA flight 32, he again exceeded Mach 1 performing rolls, pullups, sideslips, and check of stabilizer effectiveness. This was his 13th and last flight in the XS-1. He flew the first NACA research flight of the D-558-1 #3 (Skystreak) on April 22, 1949, and the first NACA research flight of the D-558-2 #2 (Skyrocket) on May 24, 1949, beginning the supersonic research program for these aircraft on June l, 1949. Conceived in 1945, the D558-1 Skystreak was designed by the Douglas Aircraft Company for the U.S. Navy Bureau of Aeronautics, in conjunction with the National Advisory Committee for Aeronautics (NACA). The Skystreaks were turojet powered aircraft that took off from the ground under their own power and had straight wings and tails. All three D-558-1 Skystreaks were powered by Allison J35-A-11 turbojet engines producing 5,000 pounds of thrust. All the Skystreaks were initially painted scarlet, which lead to the nickname 'crimson test tube.' NACA later had the color of

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.

Aerodynamic Characteristics at High Speeds of Full-Scale Propellers having Different Shank Designs

NASA Technical Reports Server (NTRS)

Maynard, Julian D.

1947-01-01

Tests of two 10-foot-diameter two-blade propellers which differed only in shank design have been made in the Langley 16-foot high-speed tunnel. The propellers are designated by their blade design numbers, NACA 10-(5)(08)-03, which had aerodynamically efficient airfoil shank sections, and NACA l0-(5)(08)-03R which had thick cylindrical shank sections typical of conventiona1 blades, The propellers mere tested on a 2000-horsepower dynamometer through a range of blade-angles from 20deg to 55deg at various rotational speeds and at airspeeds up to 496 miles per hour. The resultant tip speeds obtained simulate actual flight conditions, and the variation of air-stream Mach number with advance ratio is within the range of full-scale constant-speed propeller operation. Both propellers were very efficient, the maximum envelope efficiency being approximately 0,95 for the NACA 10-(5)(08)-03 propeller and about 5 percent less for the NACA 10-(5)(08)-03R propeller. Based on constant power and rotational speed, the efficiency of the NACA 10-(05)(08)-03 propeller was from 2.8 to 12 percent higher than that of the NACA 10-(5)(08)-03R propeller over a range of airspeeds from 225 to 450 miles per hour. The loss in maximum efficiency at the design blade angle for the NACA 10-(5)(08)-03 and 10-(5)(08)-03R propellers vas about 22 and 25 percent, respectively, for an increase in helical tip Mach number from 0.70 to 1.14.

Some NACA Muroc personnel with snowman

NASA Technical Reports Server (NTRS)

1949-01-01

The late 1940s saw increased flight activity, and more women computers were needed at the NACA Muroc Flight Test Unit than the ones who had originally arrived in 1946. A call went out to the NACA Langley, Lewis, and Ames laboratories for more women computers. Pictured in this photograph with the Snowman are some of the women computers who responded to the call for help in 1948 along with Roxanah, Emily, Dorothy, who were already here. Standing left to right: Mary (Tut) Hedgepeth, from Langley; Lilly Ann Bajus, Lewis; Roxanah Yancey, Emily Stephens, Jane Collons (Procurement), Leona Corbett (Personnel), Angel Dunn, Langley. Kneeling left to right: Dorothy (Dottie) Crawford Roth, Lewis; Dorothy Clift Hughes, and Gertrude (Trudy) Wilken Valentine, Lewis. In National Advisory Committee for Aeronautics (NACA) terminology of 1946, computers were employees who performed laborious and time-consuming mathematical calculations and data reduction from long strips of records generated by onboard aircraft instrumentation. Virtually without exception, computers were female; at least part of the rationale seems to have been the notion that the work was long and tedious, and men were not thought to have the patience to do it. Though equipment changed over the years and most computers eventually found themselves programming and operating electronic computers, as well as doing other data processing tasks, being a computer initially meant long hours with a slide rule, hunched over illuminated light boxes measuring line traces from grainy and obscure strips of oscillograph film. Computers suffered terrible eyestrain, and those who didn't begin by wearing glasses did so after a few years. But they were initially essential employees at the Muroc Flight Test Unit and NACA High-Speed Flight Research Station, taking the oscillograph flight records and 'reducing' the data on them to make them useful to research engineers, who analyzed the data.

NACA Aircraft in hangar 1953 - L-R: Three D-558-2s, D-558-1, B-47, wing of YF-84A, background are th

NASA Technical Reports Server (NTRS)

1953-01-01

for approach and landing studies. This data was used in designing later rocket-powered aircraft. Almost hidden in the back of the hangar is the ETF-51D (NACA 148/Air Force 44-84958). This two-seat trainer was used as a low-speed chase aircraft, as well as for support flights and liaison missions. It arrived at the NACA High Speed Flight Research Station on September 5, 1950, and was retired from NASA service after a taxi accident on April 15, 1959. The U.S. Army unit at Edwards AFB repaired the aircraft, and used it for helicopter chase work. On the right side of the photo the B-47A (NACA 150/Air Force 49-1900) and YF-84A (NACA 134/Air Force 45-59490) are visible. The B-47A was the first production aircraft built by Boeing. The aircraft was transferred from Langley Memorial Aeronautical Laboratory to the High-Speed Flight Research Station on March 17, 1953, where it was used for a wide range of research, including handling qualities, dynamic stability, gust loads, noise level measurements, aeroelasticity (the bending of the wings in flight), and a survey of the X-15 High Range. The YF-84A, in front of the B-47A, was used for vortex generator studies. The Dryden Flight Research Center, NASA's premier installation for aeronautical flight research, celebrated its 50th anniversary in 1996. Dryden is the 'Center of Excellence' for atmospheric flight operations. The Center's charter is to research, develop, verify, and transfer advanced aeronautics, space, and related technologies. It is located at Edwards, Calif., on the western edge of the Mojave Desert, 80 miles north of Los Angeles. Dryden's history dates back to the early fall of 1946, when a group of five aeronautical engineers arrived at what is now Edwards from the NACA's Langley Memorial Aeronautical Laboratory, Hampton, Va. Their goal was to prepare for the X-l supersonic research flights in a joint NACA-U.S. Army Air Forces-Bell Aircraft Corp. program. NACA--the National Advisory Committee for Aeronautics

Investigation of a Low-Drag Gun Port in the NACA Two-Dimensional Low-Turbulence Tunnel

NASA Technical Reports Server (NTRS)

Horton, Elmer A.; Woolard, Henry W.

1942-01-01

Tests were made in the NACA two-dimensional low-turbulence tunnel of three gun ports with a height of approximately 4 percent of the chord faired into an NACA 66,2-213 low-drag-airfoil section by bulging the section at the gun port. Gun ports faired in this manner had practically no effect on the maximum lift and the critical compressibility speed of the section and showed only small increase in the drag in the range of lift coefficients for high-speed and cruising-flight conditions.

Performance Analysis of Two Early NACA High Speed Propellers with Application to Civil Tiltrotor Configurations

NASA Technical Reports Server (NTRS)

Harris, Franklin D.

1996-01-01

The helicopter industry is vigorously pursuing development of civil tiltrotors. One key to efficient high speed performance of this rotorcraft is prop-rotor performance. Of equal, if not greater, importance is assurance that the flight envelope is free of aeroelastic instabilities well beyond currently envisioned cuise speeds. This later condition requires study at helical tip Match numbers well in excess of 1.0. Two 1940's 'supersonic' propeller experiments conducted by NACA have provided an immensely valuable data bank with which to study prop-rotor behavior at transonic and supersonic helical tip Mach numbers. Very accurate 'blades alone' data were obtained by using nearly an infinite hub. Tabulated data were recreated from the many thrust and power figures and are included in two Appendices to this report. This data set is exceptionally well suited to re-evaluating classical blade element theories as well as evolving computational fluid dynamic (CFD) analyses. A limited comparison of one propeller's experimental results to a modem rotorcraft CFD code is made. This code, referred to as TURNS, gives very encouraging results. Detailed analysis of the performance data from both propellers is provided in Appendix A. This appendix quantifies the minimum power required to produce usable prop-rotor thrust. The dependence of minimum profile power on Reynolds number is quantified. First order compressibility power losses are quantified as well and a first approximation to design air-foil thickness ratio to avoid compressibility losses is provided. Appendix A's results are applied to study high speed civil tiltrotor cruise performance. Predicted tiltrotor performance is compared to two turboprop commercial transports. The comparison shows that there is no fundamental aerodynamic reason why the rotorcraft industry could not develop civil tiltrotor aircraft which have competitive cruise performance with today's regional, turboprop airlines. Recommendations for future study

Republic P-47G Thunderbolt and the NACA Flight Operations Crew

NASA Image and Video Library

1944-03-21

The Flight Operations crew stands before a Republic P-47G Thunderbolt at the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory in Cleveland, Ohio. The laboratory’s Flight Research Section was responsible for conducting a variety of research flights. During World War II most of the test flights complemented the efforts in ground-based facilities to improve engine cooling systems or study advanced fuel mixtures. The Republic P–47G was loaned to the laboratory to test NACA modifications to the Wright R–2800 engine’s cooling system at higher altitudes. The laboratory has always maintained a fleet of aircraft so different research projects were often conducted concurrently. The flight research program requires an entire section of personnel to accomplish its work. This staff generally consists of a flight operations group, which includes the section chief, pilots and administrative staff; a flight maintenance group with technicians and mechanics responsible for inspecting aircraft, performing checkouts and installing and removing flight instruments; and a flight research group that integrates the researchers’ experiments into the aircraft. The staff at the time of this March 1944 photograph included 3 pilots, 16 planning and analysis engineers, 36 mechanics and technicians, 10 instrumentation specialists, 6 secretaries and 5 computers.

Separating the from the Imagined: Flight Research at the NACA and NASA, 1915-1998

NASA Technical Reports Server (NTRS)

Gorn, Michael H.

2000-01-01

One of the most important, but under-appreciated, aspects of the NACA/NASA mission is its aeronautical R&D efforts. Within a short time of the first flight of the Wright brothers in 1903, the United States government recognized the importance of fostering development in the new and critical field of aeronautics. NASA's predecessor, the National Advisory Committee for Aeronautics (NACA), was chartered by Congress in 1915 specifically "to supervise and direct the scientific study of the problems of flight, with a view to their practical solution. " This became an enormously important government research and development activity for the next half century, materially enhancing the development of aeronautics 'in America. The results of the NACA's research appeared in more than 16,000 research reports of one type or another, distributed widely for the benefit of all. Many of the reports documenting R&D conducted under NACA auspices are still being used today. Since the creation of NASA in 1958, the critical R&D function has continued but is not well known. This work documents the historical R&D program of the agency by focusing on flight research.

Supersonic Jet Exhaust Noise at High Subsonic Flight Speed

NASA Technical Reports Server (NTRS)

Norum, Thomas D.; Garber, Donald P.; Golub, Robert A.; Santa Maria, Odilyn L.; Orme, John S.

2004-01-01

An empirical model to predict the effects of flight on the noise from a supersonic transport is developed. This model is based on an analysis of the exhaust jet noise from high subsonic flights of the F-15 ACTIVE Aircraft. Acoustic comparisons previously attainable only in a wind tunnel were accomplished through the control of both flight operations and exhaust nozzle exit diameter. Independent parametric variations of both flight and exhaust jet Mach numbers at given supersonic nozzle pressure ratios enabled excellent correlations to be made for both jet broadband shock noise and jet mixing noise at flight speeds up to Mach 0.8. Shock noise correlated with flight speed and emission angle through a Doppler factor exponent of about 2.6. Mixing noise at all downstream angles was found to correlate well with a jet relative velocity exponent of about 7.3, with deviations from this behavior only at supersonic eddy convection speeds and at very high flight Mach numbers. The acoustic database from the flight test is also provided.

High-speed flight propulsion systems. Progress in Astronautics and Aeronautics. Vol. 137

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

Murthy, S.N.B.; Curran, E.T.

1991-01-01

Various papers on high-speed flight propulsion systems are presented. The topics addressed are: propulsion systems from takeoff to high-speed flight, propulsion system performance and integration for high Mach air-breathing flight, energy analysis of high-speed flight systems, waves and thermodynamics in high Mach number propulsive ducts, turbulent free shear layer mixing and combustion, turbulent mixing in supersonic combustion systems, mixing and mixing enhancement in supersonic reacting flowfields, study of combustion and heat-exchange processes in high-enthalpy short-duration facilities, and facility requirements for hypersonic propulsion system testing.

D-558-2 in flight with F-86 chase

NASA Technical Reports Server (NTRS)

1950-01-01

This 1950s photograph shows the Douglas D-558-2 and the North American F-86 Sabre chase aircraft in-flight. Both aircraft display early examples of sweptwing airfoils. The Douglas D-558-2 'Skyrockets' were among the early transonic research airplanes like the X-1, X-4, X-5, and X-92A. Three of the single-seat, swept-wing aircraft flew from 1948 to 1956 in a joint program involving the National Advisory Committee for Aeronautics (NACA), with its flight research done at the NACA's Muroc Flight Test Unit in Calif., redesignated in 1949 the High-Speed Flight Research Station (HSFRS); the Navy-Marine Corps; and the Douglas Aircraft Co. The HSFRS became the High-Speed Flight Station in 1954 and is now known as the NASA Dryden Flight Research Center. The Skyrocket made aviation history when it became the first airplane to fly twice the speed of sound. The 2 in the aircraft's designation referred to the fact that the Skyrocket was the phase-two version of what had originally been conceived as a three-phase program, with the phase-one aircraft having straight wings. The third phase, which never came to fruition, would have involved constructing a mock-up of a combat-type aircraft embodying the results from the testing of the phase one and two aircraft. Douglas pilot John F. Martin made the first flight at Muroc Army Airfield (later renamed Edwards Air Force Base) in Calif. on February 4, 1948. The goals of the program were to investigate the characteristics of swept-wing aircraft at transonic and supersonic speeds with particular attention to pitch-up (uncommanded rotation of the nose of the airplane upwards)--a problem prevalent in high-speed service aircraft of that era, particularly at low speeds during take-off and landing and in tight turns. The three aircraft gathered a great deal of data about pitch-up and the coupling of lateral (yaw) and longitudinal (pitch) motions; wing and tail loads, lift, drag, and buffeting characteristics of swept-wing aircraft at transonic

D-558-2 launch and flight

NASA Technical Reports Server (NTRS)

1954-01-01

This 19-second video clip shows the D-558-2 being dropped from the P2B-1S mothership, flying and landing. Near the end of the clip the wing of the TF-86 video chase aircraft is visible landing on the Rogers Dry Lakebed next to the Skyrocket. The Douglas D-558-2 Skyrocket airplanes were early transonic research airplanes like the X-1, X-4, X-5, and X-92A. Three of these single-seat, swept-wing aircraft flew from 1948 to 1956 in a joint program involving the National Advisory Committee for Aeronautics (NACA); the Navy-Marine Corps; and the Douglas Aircraft Company, Long Beach, California. Flight research was done at the NACA Muroc Flight Test Unit in California, redesignated in 1949 the High-Speed Flight Research Station (HSFRS). The HSFRS is now known as the NASA Dryden Flight Research Center, Edwards, California. The Skyrocket made aviation history when it became the first airplane to fly twice the speed of sound. Douglas Aircraft pilot John F. Martin made the first flight at Muroc Army Airfield (later renamed Edwards Air Force Base) in California on February 4, 1948. The goals of that program were to investigate the characteristics of swept-wing aircraft at transonic and supersonic speeds with particular attention to pitchup (uncommanded rotation of the nose of the airplane upwards) -- a problem prevalent in high-speed service aircraft of that era, particularly at low speeds during takeoff and landing and in tight turns. The three aircraft gathered a great deal of data about pitchup and the coupling of lateral (yaw) and longitudinal (pitch) motions; wing and tail loads, lift, drag, and buffeting characteristics of swept-wing aircraft at transonic and supersonic speeds; and the effects of the rocket exhaust plume on lateral dynamic stability throughout the speed range. (Plume effects were a new experience for aircraft.) The number three aircraft also gathered information about the effects of external stores (bomb shapes, drop tanks) upon the aircraft behavior in

McDonnell FH-1 Phantom Destroyed for the NACA Crash Fire Program

NASA Image and Video Library

1955-04-21

Researchers at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory purposely wreck a McDonnell FH-1 Phantom as part of the laboratory’s Crash Fire Program. NACA Lewis researchers created the program in 1949 to investigate methods for improving survival rates for take-off and landing-type crashes. In these types of crashes, the passengers often survived the impact only to perish in the ensuing fire. Previously there had been little information on the nature of post-crash fires, and it was difficult to use analytical studies in this area. Irving Pinkel, Chief of the Lewis Flight Propulsion Division, was the primary researcher. He enlisted flight safety specialist and aeronautics researchers G. Merritt Preston and Gerard Pesman, mechanical engineer Dugald Black, and others. The tests were conducted at the nearby Ravenna Arsenal using decommissioned Air Force fighter and transport aircraft. The pilotless aircraft were accelerated down a rail on a 1700-foot track at take-off speeds and run into barriers to simulate a variety of different types of crashes. The first barrier stripped off the landing gears and another briefly sent the aircraft off the ground before it crashed into a dirt mound. Telemetry and high-speed cameras were crucial elements in these studies. NACA Lewis photographer Bill Wynne developed a method for inserting timekeeping devices on test film that were able to show time to one thousandth of a second.

Exploring Flight Research with Experimental Gliders

NASA Technical Reports Server (NTRS)

1999-01-01

A look at the research aircraft flown by NASA and its predecessor, the National Advisory Committee for Aeronautics (NACA), since the 1940's reveals an evolution of wing designs. In fact, each of the first series of NACA experimental research aircraft ("X-planes") used different wing and tail configurations to tackle the problems of supersonic flight, These early jet aircraft had straight wings (X-1), wings that angled (swept) toward the tail (X-2), triangular (delta) wings (XF-92), and wings that could be moved in flight to change the angle of backward sweep (X-5). Each design added to our knowledge of high-speed flight.

NACA's Lockheed F-94B Starfire with Audio Recording Devices

NASA Image and Video Library

1957-07-21

A Lockheed F-94B Starfire being equipped with an audio recording machine and sensors at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The NACA was investigating the acoustic effects caused by the engine’s nozzle and the air flowing along the fuselage. Airline manufacturers would soon be introducing jet engines on their passenger aircraft, and there was concern regarding the noise levels for both the passengers and public on the ground. NACA Lewis conducted a variety of noise reduction studies in its wind tunnels, laboratories, and on a F2H-2B Banshee aircraft. The F2H-2B Banshee’s initial test flights in 1955 and 1956 measured the noise emanating directly from airflow over the aircraft’s surfaces, particularly the wings. This problem was particularly pronounced at high subsonic speeds. The researchers found the majority of the noise occurred in the low and middle octaves. These investigations were enhanced with a series of flights using the F-94B Starfire. The missions measured wall-pressure, turbulence fluctuations, and mean velocity profiles. Mach 0.3 to 0.8 flights were flown at altitudes of 10,000, 20,000, and 30,000 feet with microphones mounted near the forward fuselage and on a wing. The results substantiated the wind tunnel findings. This photograph shows the tape recorder being installed in the F-94B’s nose.

North American XF-82 Twin Mustang Prepares for Ramjet Test Flight

NASA Image and Video Library

1949-04-21

Pilot William Swann, right cockpit, prepares the North American XF-82 Twin Mustang for flight at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The aircraft was one of only two prototypes built by North American in October 1945 and powered by Packard Merlin V-1650 piston engines. Over 270 of the F-82 long-distance pursuit fighters were produced during the 1940s. The Mustang’s unique two-pilot configuration allowed one pilot to rest during the long missions and thus be ready for action upon arrival. The NACA took possession of this XF-82 in October 1947. NACA Lewis used the XF-82 as a test bed for ramjet flight tests. Ramjets are continually burning tubes that use the compressed atmospheric air to produce thrust. Ramjets are extremely efficient at high speeds, but rely on some sort of booster to attain that high speed. NACA Lewis undertook an extensive ramjet program in the 1940s that included combustion studies in the Altitude Wind Tunnel, a number of flight tests, and missile drops from aircraft. The 16-inch diameter ramjet missile was fixed to the XF-82 Mustang’s wing and dropped from high altitudes off of Wallops Island. The tests determined the ramjet’s performance and operational characteristics in the transonic range.

Context-dependent flight speed: evidence for energetically optimal flight speed in the bat Pipistrellus kuhlii?

PubMed

Grodzinski, Uri; Spiegel, Orr; Korine, Carmi; Holderied, Marc W

2009-05-01

1. Understanding the causes and consequences of animal flight speed has long been a challenge in biology. Aerodynamic theory is used to predict the most economical flight speeds, minimizing energy expenditure either per distance (maximal range speed, Vmr) or per time (minimal power speed, Vmp). When foraging in flight, flight speed also affects prey encounter and energy intake rates. According to optimal flight speed theory, such effects may shift the energetically optimal foraging speed to above Vmp. 2. Therefore, we predicted that if energetic considerations indeed have a substantial effect on flight speed of aerial-hawking bats, they will use high speed (close to Vmr) to commute from their daily roost to the foraging sites, while a slower speed (but still above Vmp) will be preferred during foraging. To test these predictions, echolocation calls of commuting and foraging Pipistrellus kuhlii were recorded and their flight tracks were reconstructed using an acoustic flight path tracking system. 3. Confirming our qualitative prediction, commuting flight was found to be significantly faster than foraging flight (9.3 vs. 6.7 m s(-1)), even when controlling for its lower tortuosity. 4. In order to examine our quantitative prediction, we compared observed flight speeds with Vmp and Vmr values generated for the study population using two alternative aerodynamic models, based on mass and wing morphology variables measured from bats we captured while commuting. The Vmp and Vmr values generated by one of the models were much lower than our measured flight speed. According to the other model used, however, measured foraging flight was faster than Vmp and commuting flight slightly slower than Vmr, which is in agreement with the predictions of optimal flight speed theory. 5. Thus, the second aerodynamic model we used seems to be a reasonable predictor of the different flight speeds used by the bats while foraging and while commuting. This supports the hypothesis that bats fly

Helicopter pilot scan techniques during low-altitude high-speed flight.

PubMed

Kirby, Christopher E; Kennedy, Quinn; Yang, Ji Hyun

2014-07-01

This study examined pilots' visual scan patterns during a simulated high-speed, low-level flight and how their scan rates related to flight performance. As helicopters become faster and more agile, pilots are expected to navigate at low altitudes while traveling at high speeds. A pilot's ability to interpret information from a combination of visual sources determines not only mission success, but also aircraft and crew survival. In a fixed-base helicopter simulator modeled after the U.S. Navy's MH-60S, 17 active-duty Navy helicopter pilots with varying total flight times flew and navigated through a simulated southern Californian desert course. Pilots' scan rate and fixation locations were monitored using an eye-tracking system while they flew through the course. Flight parameters, including altitude, were recorded using the simulator's recording system. Experienced pilots with more than 1000 total flight hours better maintained a constant altitude (mean altitude deviation = 48.52 ft, SD = 31.78) than less experienced pilots (mean altitude deviation = 73.03 ft, SD = 10.61) and differed in some aspects of their visual scans. They spent more time looking at the instrument display and less time looking out the window (OTW) than less experienced pilots. Looking OTW was associated with less consistency in maintaining altitude. Results may aid training effectiveness specific to helicopter aviation, particularly in high-speed low-level flight conditions.

Budgerigar flight in a varying environment: flight at distinct speeds?

PubMed

Schiffner, Ingo; Srinivasan, Mandyam V

2016-06-01

How do flying birds respond to changing environments? The behaviour of budgerigars, Melopsittacus undulatus, was filmed as they flew through a tapered tunnel. Unlike flying insects-which vary their speed progressively and continuously by holding constant the optic flow induced by the walls-the birds showed a tendency to fly at only two distinct, fixed speeds. They switched between a high speed in the wider section of the tunnel, and a low speed in the narrower section. The transition between the two speeds was abrupt, and anticipatory. The high speed was close to the energy-efficient, outdoor cruising speed for these birds, while the low speed was approximately half this value. This is the first observation of the existence of two distinct, preferred flight speeds in birds. A dual-speed flight strategy may be beneficial for birds that fly in varying environments, with the high speed set at an energy-efficient value for flight through open spaces, and the low speed suited to safe manoeuvring in a cluttered environment. The constancy of flight speed within each regime enables the distances of obstacles and landmarks to be directly calibrated in terms of optic flow, thus facilitating simple and efficient guidance of flight through changing environments. © 2016 The Author(s).

NACA D-558-2 Test Force w/P2B-1S & F-86

NASA Technical Reports Server (NTRS)

1952-01-01

These people and this equipment supported the flight of the NACA D-558-2 Skyrocket at the High-Speed Flight Station at South Base, Edwards AFB. Note the two Sabre chase planes, the P2B-1S launch aircraft, and the profusion of ground support equipment, including communications, tracking, maintenance, and rescue vehicles. Research pilot A. Scott Crossfield stands in front of the Skyrocket. Three D-558-2 'Skyrockets' were built by Douglas Aircraft, Inc. for NACA and the Navy. The mission of the D-558-2 program was to investigate the flight characteristics of a swept-wing aircraft at high supersonic speeds. Particular attention was given to the problem of 'pitch-up,' a phenomenon often encountered with swept-wing configured aircraft. The D-558-2 was a single-place, 35-degree swept-wing aircraft measuring 42 feet in length. It was 12 feet, 8 inches in height and had a wingspan of 25 feet. Fully fueled it weighed from about 10,572 pounds to 15,787 pounds depending on configuration. The first of the three D-558-IIs had a Westinghouse J34-40 jet engine and took off under its own power. The second was equipped with a turbojet engine replaced in 1950 with a Reaction Motors Inc. LR8-RM-6 rocket engine. This aircraft was modified so it could be air-launched from a P2B-1S (Navy designation for the B-29) carrier aircraft. The third Skyrocket had the jet engine and the rocket engine but was also modified so it could be air-launched. The jet engine was for takeoff and climbing to altitude and the four-chambered rocket engine was for reaching supersonic speeds. The rocket engine was rated at 6,000 pounds of thrust. The D-558-2 was first flown on Feb. 4, 1948, by John Martin, a Douglas test pilot. A NACA pilot, Scott Crossfield, became the first person to fly faster than twice the speed of sound when he piloted the D-558-II to its maximum speed of 1,291 miles per hour on Nov. 20, 1953. Its peak altitude, 83,235 feet, a record in its day, was reached with USMC Lt. Col. Marion Carl

NACA Aircraft in hangar 1953 - clockwise from front center: YF-84A, D-558-1, D-558-2, B-47, X-1 ship

NASA Technical Reports Server (NTRS)

1953-01-01

the X-1 is the XF-92A (Air Force 46-682). Unlike the X-1 and D-558 aircraft, the XF-92A was not designed as a research aircraft, but as the prototype of a delta-wing fighter. While the effort was unsuccessful, the XF-92A offered the chance to test a delta wing aircraft. A brief series of 25 flights were made using the aircraft in 1953. These showed the aircraft had violent pitch-up tendencies during turns. Despite the problems, the XF-92A contributed to later delta wing aircraft, like the F-102, F-106, and B-58. Behind the B-47, in the back of the hangar, are four other aircraft. From left to right, they are the second X-4 (Air Force 46-677) research aircraft. It was operated by the NACA from May 8, 1950, to March 22, 1954, when it left the High-Speed Flight Research Station for the U.S. Air Force Museum. It was designed to test the use of swept wings but no horizontal stabilizers. This proved to have poor transonic stability. Next to it is the ETF-51D Mustang (NACA 148/Air Force 44-84958) used for low-speed chase missions, as well as support and liaison flights. On the right side of the B-47 is the first D-558-1. Originally given the Navy number 37970, it was flown as part of the Douglas contractor program. When this was completed, the aircraft was turned over to the NACA on April 11, 1949. Although the aircraft was designation 'NACA 140,' it was never flown again. Instead, it was used to provide spare parts to keep the third D-558-1 in operation. In this photo the aircraft is partially disassembled. The final aircraft is the first X-5 (Air Force 50-1838). This was a research aircraft used to test the concept of pivoting wings which could change their sweep angle in flight. The results were mixed; the X-5 had vicious stall behavior due to the poor position of the tail and stabilizers. The mechanism used by the 'variable-sweep wing' was also complex, which limited its usefulness. Despite these problems, the X-5's primary advantage was that it was equivalent to a whole

Investigation of Inner Loop Flight Control Strategies for High-Speed Research

NASA Technical Reports Server (NTRS)

Newman, Brett; Kassem, Ayman

1999-01-01

This report describes the activities and findings conducted under contract NAS1-19858 with NASA Langley Research Center. Subject matter is the investigation of suitable flight control design methodologies and solutions for large, flexible high-speed vehicles. Specifically, methodologies are to address the inner control loops used for stabilization and augmentation of a highly coupled airframe system possibly involving rigid-body motion, structural vibrations, unsteady aerodynamics, and actuator dynamics. Techniques considered in this body of work are primarily conventional-based, and the vehicle of interest is the High-Speed Civil Transport (HSCT). Major findings include 1) current aeroelastic vehicle modeling procedures require further emphasis and refinement, 2) traditional and nontraditional inner loop flight control strategies employing a single feedback loop do not appear sufficient for highly flexible HSCT class vehicles, 3) inner loop flight control systems will, in all likelihood, require multiple interacting feedback loops, and 4) Ref. H HSCT configuration presents major challenges to designing acceptable closed-loop flight dynamics.

High-speed imaging of the transient ice accretion process on a NACA 0012 airfoil

NASA Astrophysics Data System (ADS)

Waldman, Rye; Hu, Hui

2014-11-01

Ice accretion on aircraft wings poses a performance and safety threat as aircraft encounter supercooled droplets suspended in the cloud layer. The details of the ice accretion depend on the atmospheric conditions and the fight parameters. We present the measurement results of the experiments conducted in the Iowa State icing wind tunnel on a NACA 0012 airfoil to study the transient ice accretion process under varying icing conditions. The icing process on the wing consists of a complex interaction of water deposition, surface water transport, and freezing. The aerodynamics affects the water deposition, the heat and mass transport, and ice accumulation; meanwhile, the accumulating ice also affects the aerodynamics. High-speed video of the unsteady icing accretion process was acquired under controlled environmental conditions to quantitatively measure the transient water run back, rivulet formation, and accumulated ice growth, and the experiments show how varying the environmental conditions modifies the ice accretion process. Funding support from the Iowa Energy Center with Grant No. 14-008-OG and National Science Foundation (NSF) with Grant No. CBET-1064196 and CBET-1438099 is gratefully acknowledged.

NACA Conference on Some Problems of Aircraft Operation: A Compilation of the Papers Presented

NASA Technical Reports Server (NTRS)

1950-01-01

This volume contains copies of the technical papers presented at the NACA Conference on Some Problems of Aircraft Operation on October 9 and 10, 1950 at the Lewis Flight Propulsion Laboratory. This conference was attended by members of the aircraft industry and military services. The original presentation and this record are considered as complementary to, rather than as substitutes for, the Committee's system of complete and formal reports. A list of the conferees is included. [Contents include four subject areas: Atmospheric Turbulence and its Effect on Aircraft Operation; Some Aspects of Aircraft Safety - Icing, Ditching and Fire; Aerodynamic Considerations for High-Speed Transport Airplanes; Propulsion Considerations for High-Speed Transport Airplanes.

NACA Study of Crash Fires with a Fairchild C-82 Packet

NASA Image and Video Library

1950-06-21

Researchers at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory purposely crash a Fairchild C-82 Packet aircraft to study flame propagation. A rash of passenger aircraft crashes in 1946 and 1947 spurred a White House call for an investigatory board staffed by members of the Civil Aeronautics Board, military, and the NACA. The group addressed fire segregation, extinguishment, and prevention. The NACA established a Subcommittee on Aircraft Fire Prevention in February 1948 to coordinate its efforts. The Lewis team simulated situations in which an aircraft failed to become airborne during takeoff resulting in crashes into embankments and other objects. The Lewis researchers initially used surplus C-46 and C-82 military transport planes. In these situations, the aircraft generally suffered damage to its fuel system and other components, but was structurally survivable. The aircraft were mounted to a rail that ran down a 1700-foot long test runway. The aircraft was secured at the starting point with an anchor pier so it could get its engines up to takeoff speed before launching down the track. Barriers at the end of the runway were designed to simulate a variety of different types of crashes. Telemetry and high-speed cameras were crucial elements in these studies. The preliminary testing phase identified potential ignition sources and analyzed the spread of flammable materials.

Flight Investigation at High Speeds of the Drag of Three Airfoils and a Circular Cylinder Representing Full-Scale Propeller Shanks

NASA Technical Reports Server (NTRS)

Barlow, William H

1946-01-01

Tests have been made at high speeds to determine the drag of models, simulating propeller shanks, in the form of a circular cylinder and three airfoils, the NACA 16-025, the NACA 16-040, and the NACA 16-040 with the rear 25 percent chord cut off. All the models had a maximum thickness of 4 1/2 inches to conform with average propeller-shank dimensions and a span of 20 1/4 inches. For the tests the models were supported perpendicular to the lower surface of the wing of an XP-51 airplane. A wake-survey rake mounted below the wing directly behind the models was used to determine profile drag of Mach numbers of 0.3 to 0.8 over a small range of angle of attack. The drag of the cylinder was also determined from pressure-distribution and force measurements.

D-558-1 in flight

NASA Technical Reports Server (NTRS)

1952-01-01

This 1952 NACA High-Speed Flight Research Station inflight photograph of the Douglas D-558-1 #3 Skystreak. Even with partial cloud cover the white aircraft was easy to see. The D-558-1 reflected NACA (National Advisory Committee for Aeronautics) ideas on a transonic research aircraft. NACA engineers favored a turbojet engine, as they saw a rocket-powered research aircraft as too risky. They were also more interested in transonic speed--from about Mach 0.8 to Mach 1.2--than in breaking the 'sound barrier' for the sake of doing so. The Army Air Forces had a different approach and developed the rocket-powered XS-1, which the NACA also flew and supported, although it favored the D-558-1. Conceived in 1945, the D558-1 Skystreak was designed by the Douglas Aircraft Company for the U.S. Navy Bureau of Aeronautics, in conjunction with the National Advisory Committee for Aeronautics (NACA). The Skystreaks were turojet powered aircraft that took off from the ground under their own power and had straight wings and tails. All three D-558-1 Skystreaks were powered by Allison J35-A-11 turbojet engines producing 5,000 pounds of thrust. All the Skystreaks were initially painted scarlet, which lead to the nickname 'crimson test tube.' NACA later had the color of the Skystreaks changed to white to improve optical tracking and photography. The Skystreaks carried 634 pounds of instrumentation and were ideal first-generation, simple, transonic research airplanes. Much of the research performed by the D-558-1 Skystreaks, was quickly overshadowed in the public mind by Chuck Yeager and the X-1 rocketplane. However, the Skystreak performed an important role in aeronautical research by flying for extended periods of time at transonic speeds, which freed the X-1 to fly for limited periods at supersonic speeds.

Ramjet Testing in the NACA's Altitude Wind Tunnel

NASA Image and Video Library

1946-02-21

A 20-inch diameter ramjet installed in the Altitude Wind Tunnel at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The Altitude Wind Tunnel was used in the 1940s to study early ramjet configurations. Ramjets provide a very simple source of propulsion. They are basically a tube which takes in high-velocity air, ignites it, and then expels the expanded airflow at a significantly higher velocity for thrust. Ramjets are extremely efficient and powerful but can only operate at high speeds. Therefore a turbojet or rocket was needed to launch the vehicle. This NACA-designed 20-inch diameter ramjet was installed in the Altitude Wind Tunnel in May 1945. The ramjet was mounted under a section of wing in the 20-foot diameter test section with conditioned airflow ducted directly to the engine. The mechanic in this photograph was installing instrumentation devices that led to the control room. NACA researchers investigated the ramjet’s overall performance at simulated altitudes up to 47,000 feet. Thrust measurements from these runs were studied in conjunction with drag data obtained during small-scale studies in the laboratory’s small supersonic tunnels. An afterburner was attached to the ramjet during the portions of the test program. The researchers found that an increase in altitude caused a reduction in the engine’s horsepower. They also determined the optimal configurations for the flameholders, which provided the engine’s ignition source.

NACA Researcher Examines the Cyclotron

NASA Image and Video Library

1951-02-21

Researcher James Blue examines the new cyclotron at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. Researchers at NACA Lewis began postulating about the use of atomic power for propulsion immediately after World War II. The NACA concentrated its efforts on the study of high temperature materials and heat transfer since it did not have access to the top secret fission information. The military studied the plausibility of nuclear propulsion for aircraft in the late 1940s. The military program was cancelled after four years without any breakthroughs, but the Atomic Energy Commission took on the effort in 1951. The NACA Lewis laboratory was expanding its nuclear-related research during this period. In 1948, Lewis engineers were assigned to the Oak Ridge National Laboratory to obtain expertise in high temperature heat transfer and advanced materials technology. The following year a new 80-person Nuclear Reactor Division was created, and an in-house nuclear school was established to train these researchers. The cyclotron was built behind the Materials and Structures Laboratory to support thermodynamic and materials research for both nuclear aircraft and nuclear rockets. The original NACA Lewis cyclotron was used to accelerate two kinds of particles. To better match the space radiation environment, the cyclotron was later modified to accelerate particles of the newly-discovered Van Allen radiation belts.

Future ultra-speed tube-flight

NASA Astrophysics Data System (ADS)

Salter, Robert M.

1994-05-01

Future long-link, ultra-speed, surface transport systems will require electromagnetically (EM) driven and restrained vehicles operating under reduced-atmosphere in very straight tubes. Such tube-flight trains will be safe, energy conservative, pollution-free, and in a protected environment. Hypersonic (and even hyperballistic) speeds are theoretically achievable. Ultimate system choices will represent tradeoffs between amoritized capital costs (ACC) and operating costs. For example, long coasting links might employ aerodynamic lift coupled with EM restraint and drag make-up. Optimized, combined EM lift, and thrust vectors could reduce energy costs but at increased ACC. (Repulsive levitation can produce lift-over-drag l/d ratios a decade greater than aerodynamic), Alternatively, vehicle-emanated, induced-mirror fields in a conducting (aluminum sheet) road bed could reduce ACC but at substantial energy costs. Ultra-speed tube flight will demand fast-acting, high-precision sensors and computerized magnetic shimming. This same control system can maintain a magnetic 'guide way' invariant in inertial space with inertial detectors imbedded in tube structures to sense and correct for earth tremors. Ultra-speed tube flight can complete with aircraft for transit time and can provide even greater passenger convenience by single-model connections with local subways and feeder lines. Although cargo transport generally will not need to be performed at ultra speeds, such speeds may well be desirable for high throughput to optimize channel costs. Thus, a large and expensive pipeline might be replaced with small EM-driven pallets at high speeds.

Future ultra-speed tube-flight

NASA Technical Reports Server (NTRS)

Salter, Robert M.

1994-01-01

Future long-link, ultra-speed, surface transport systems will require electromagnetically (EM) driven and restrained vehicles operating under reduced-atmosphere in very straight tubes. Such tube-flight trains will be safe, energy conservative, pollution-free, and in a protected environment. Hypersonic (and even hyperballistic) speeds are theoretically achievable. Ultimate system choices will represent tradeoffs between amoritized capital costs (ACC) and operating costs. For example, long coasting links might employ aerodynamic lift coupled with EM restraint and drag make-up. Optimized, combined EM lift, and thrust vectors could reduce energy costs but at increased ACC. (Repulsive levitation can produce lift-over-drag l/d ratios a decade greater than aerodynamic), Alternatively, vehicle-emanated, induced-mirror fields in a conducting (aluminum sheet) road bed could reduce ACC but at substantial energy costs. Ultra-speed tube flight will demand fast-acting, high-precision sensors and computerized magnetic shimming. This same control system can maintain a magnetic 'guide way' invariant in inertial space with inertial detectors imbedded in tube structures to sense and correct for earth tremors. Ultra-speed tube flight can complete with aircraft for transit time and can provide even greater passenger convenience by single-model connections with local subways and feeder lines. Although cargo transport generally will not need to be performed at ultra speeds, such speeds may well be desirable for high throughput to optimize channel costs. Thus, a large and expensive pipeline might be replaced with small EM-driven pallets at high speeds.

Ram-recovery Characteristics of NACA Submerged Inlets at High Subsonic Speeds

NASA Technical Reports Server (NTRS)

Hall, Charles F; Frank, Joseph L

1948-01-01

Results are presented of an experimental investigation of the characteristics of NACA submerged inlets on a model of a fighter airplane for Mach numbers from 0.30 to 0.875. The effects on the ram-recovery ratio at the inlets of Mach number, angle of attack, boundary-layer thickness on the fuselage, inlet location, and boundary-layer deflectors are shown. The data indicate only a slight decrease in ram-recovery ratio for the inlets ahead of or just behind the wing leading edge as Mach number increased, but showed large decreases at high Mach numbers for the inlets aft of the point of maximum thickness of the wing.

Selected Examples of NACA/NASA Supersonic Flight Research

NASA Technical Reports Server (NTRS)

Saltzman, Edwin J.; Ayers, Theodore G.

1995-01-01

The present Dryden Flight Research Center, a part of the National Aeronautics and Space Administration, has a flight research history that extends back to the mid-1940's. The parent organization was a part of the National Advisory Committee for Aeronautics and was formed in 1946 as the Muroc Flight Test Unit. This document describes 13 selected examples of important supersonic flight research conducted from the Mojave Desert location of the Dryden Flight Research Center over a 4 decade period beginning in 1946. The research described herein was either obtained at supersonic speeds or enabled subsequent aircraft to penetrate or traverse the supersonic region. In some instances there accrued from these research efforts benefits which are also applicable at lower or higher speed regions. A major consideration in the selection of the various research topics was the lasting impact they have had, or will have, on subsequent supersonic flight vehicle design, efficiency, safety, and performance or upon improved supersonic research techniques.

Comparative Flight Performance with an NACA Roots Supercharger and a Turbocentrifugal Supercharger

NASA Technical Reports Server (NTRS)

Schey, Oscar W; Young, Alfred W

1931-01-01

This report presents the comparative flight results of a roots supercharger and a turbocentrifugal supercharger. The tests were conducted using a modified DH-4M2 airplane. The rate of climb and the high speed in level flight of the airplane were obtained for each supercharger from sea level to the ceiling. The unsupercharged performance with each supercharger mounted in place was also determined. The results of these tests show that the ceiling and rate of climb obtained were nearly the same for each supercharger, but that the high speed obtained with the turbocentrifugal was better than that obtained with the roots. The high-speed performance at 21,000 feet was 122 and 142 miles per hour for the roots and turbocentrifugal, respectively.

Pulse Detonation Engines for High Speed Flight

NASA Technical Reports Server (NTRS)

Povinelli, Louis A.

2002-01-01

Revolutionary concepts in propulsion are required in order to achieve high-speed cruise capability in the atmosphere and for low cost reliable systems for earth to orbit missions. One of the advanced concepts under study is the air-breathing pulse detonation engine. Additional work remains in order to establish the role and performance of a PDE in flight applications, either as a stand-alone device or as part of a combined cycle system. In this paper, we shall offer a few remarks on some of these remaining issues, i.e., combined cycle systems, nozzles and exhaust systems and thrust per unit frontal area limitations. Currently, an intensive experimental and numerical effort is underway in order to quantify the propulsion performance characteristics of this device. In this paper, we shall highlight our recent efforts to elucidate the propulsion potential of pulse detonation engines and their possible application to high-speed or hypersonic systems.

NACA Photographer Films a Ramjet Test

NASA Image and Video Library

1946-10-21

A National Advisory Committee for Aeronautics (NACA) photographer films the test of a ramjet engine at the Lewis Flight Propulsion Laboratory. The laboratory had an arsenal of facilities to test the engines and their components, and immersed itself in the study of turbojet and ramjet engines during the mid-1940s. Combustion, fuel injection, flameouts, and performance at high altitudes were of particular interest to researchers. They devised elaborate schemes to instrument the engines in order to record temperature, pressure, and other data. Many of the tests were also filmed so Lewis researchers could visually review the combustion performance along with the data. The photographer in this image was using high-speed film to document a thrust augmentation study at Lewis’ Jet Static Propulsion Laboratory. The ramjet in this photograph was equipped with a special afterburner as part of a general effort to improve engine performance. Lewis’ Photo Lab was established in 1942. The staff was expanded over the next few years as more test facilities became operational. The Photo Lab’s staff and specialized equipment have been key research tools for decades. They accompany pilots on test flights, use high-speed cameras to capture fleeting processes like combustion, and work with technology, such as the Schlieren camera, to capture supersonic aerodynamics. In addition, the group has documented construction projects, performed publicity work, created images for reports, and photographed data recording equipment.

Flight Calibration of four airspeed systems on a swept-wing airplane at Mach numbers up to 1.04 by the NACA radar-phototheodolite method

NASA Technical Reports Server (NTRS)

Thompson, Jim Rogers; Bray, Richard S; COOPER GEORGE E

1950-01-01

The calibrations of four airspeed systems installed in a North American F-86A airplane have been determined in flight at Mach numbers up to 1.04 by the NACA radar-phototheodolite method. The variation of the static-pressure error per unit indicated impact pressure is presented for three systems typical of those currently in use in flight research, a nose boom and two different wing-tip booms, and for the standard service system installed in the airplane. A limited amount of information on the effect of airplane normal-force coefficient on the static-pressure error is included. The results are compared with available theory and with results from wind-tunnel tests of the airspeed heads alone. Of the systems investigated, a nose-boom installation was found to be most suitable for research use at transonic and low supersonic speeds because it provided the greatest sensitivity of the indicated Mach number to a unit change in true Mach number at very high subsonic speeds, and because it was least sensitive to changes in airplane normal-force coefficient. The static-pressure error of the nose-boom system was small and constant above a Mach number of 1.03 after passage of the fuselage bow shock wave over the airspeed head.

Flight Characteristics of a 1/4-Scale Model of the XFV-1 Airplane (TED No. NACA DE-378)

NASA Technical Reports Server (NTRS)

Kelly, Mark W.; Smaus, Louis H.

1952-01-01

A l/4-scale dynamically similar model of the XFV-1 airplane has been flown in the Ames 40- by 80-foot wind tunnel, using the trailing flight-cable technique. This investigation was devoted to establishing the flight characteristics of the model in forward flight from hovering to wing stall, and in yawed flight (wing span alined with the relative wind) from hovering to the maximum speed at which controlled flight could be maintained. Landings, take-offs, and hovering characteristics in flights close to the ground were also investigated.. Since the remote control system for the model was rather complicated and provided artificial damping about the pitch, roll, and yaw axes, sufficient data from the control-system calibration tests are included in this report to specify the performance of the control system in relation to both the model flight tests and the design of an automatic control system for the full-scale airplane. The model in hovering flight appeared to be neutrally stable. The response of the model to the controls was very rapid, and it was always necessary to provide some amount of artificial damping to maintain control. The model could be landed with little difficulty by hovering approximately a foot above the floor and then cutting the power. Take-offs were more difficult to perform, primarily because the rate of change in power to the model motors was limited by the characteristics of the available power source. The model was,capable of controlled yawed flight at translational velocities up to and including 20 feet per second. The effectiveness of the controls decreased with increasing speed, however, and at 25 fps control in pitch, and probably roll, was lost completely. The model was flown in controlled forward flight from hovering up to 70 fps. During these flights the model appeared to be more difficult to control in yaw than it was in pitch or roll. The flights of the model were recorded by motion picture cameras. These motion pictures are

High-speed civil transport flight- and propulsion-control technological issues

NASA Technical Reports Server (NTRS)

Ray, J. K.; Carlin, C. M.; Lambregts, A. A.

1992-01-01

Technology advances required in the flight and propulsion control system disciplines to develop a high speed civil transport (HSCT) are identified. The mission and requirements of the transport and major flight and propulsion control technology issues are discussed. Each issue is ranked and, for each issue, a plan for technology readiness is given. Certain features are unique and dominate control system design. These features include the high temperature environment, large flexible aircraft, control-configured empennage, minimizing control margins, and high availability and excellent maintainability. The failure to resolve most high-priority issues can prevent the transport from achieving its goals. The flow-time for hardware may require stimulus, since market forces may be insufficient to ensure timely production. Flight and propulsion control technology will contribute to takeoff gross weight reduction. Similar technology advances are necessary also to ensure flight safety for the transport. The certification basis of the HSCT must be negotiated between airplane manufacturers and government regulators. Efficient, quality design of the transport will require an integrated set of design tools that support the entire engineering design team.

X-2 in flight after drop from B-50 mothership

NASA Technical Reports Server (NTRS)

1956-01-01

The Bell Aircraft Company X-2 (46-674) drops away from its Boeing B-50 mothership in this photo. Lt. Col. Frank 'Pete' Everest piloted 674 on its first unpowered flight on 5 August 1954. He made the first rocket-powered flight on 18 November 1955. Everest made the first supersonic X-2 flight in 674 on 25 April 1956, achieving a speed of Mach 1.40. In July, he reached Mach 2.87, just short of the Mach 3 goal. The other X-2, 675, was written off prior to making any powered flights. An explosion during a captive flight resulted in the death of Bell test pilot Jean 'Skip' Ziegler. The X-2 was jettisoned over Lake Ontario, and the launch aircraft was damaged beyond repair. The first X-2, 674, continued flying, making a total of 17 launches. On 7 September 1956, Capt. Iven Kincheloe became the first man to exceed 100,000 feet when he reached an altitude of 126,200 feet in 674. The X-2, initially an Air Force program, was scheduled to be transferred to the civilian National Advisory Committee for Aeronautics (NACA) for scientific research. The Air Force delayed turning the aircraft over to the NACA in the hope of attaining Mach 3 in the airplane. The service requested and received a two-month extension to qualify another Air Force test pilot, Capt. Miburn 'Mel' Apt, in the X-2 and attempt to exceed Mach 3. After several ground briefings in the simulator, Apt (with no previous rocket plane experience) made his flight on 27 September 1956. Apt raced away from the B-50 under full power, quickly outdistancing the F-100 chase planes. At high altitude, he nosed over, accelerating rapidly. The X-2 reached Mach 3.2 (2,094 mph) at 65,000 feet. Apt became the first man to fly more than three times the speed of sound. Still above Mach 3, he began an abrupt turn back to Edwards. This maneuver proved fatal as the X-2 began a series of diverging rolls and tumbled out of control. Apt tried to regain control of the aircraft. Unable to do so, Apt separated the escape capsule. Too late, he

Investigation of the NACA 4-(5)(08)-03 and NACA 4-(10)(08)-03 Two-Blade Propellers at Forward Mach Numbers to 0.725 to Determine the Effects of Camber and Compressibility on Performance

NASA Technical Reports Server (NTRS)

Delano, James B

1951-01-01

As part of a general investigation of propellers at high forward speeds, tests of two-blade propellers having the NACA 4-(5)(08)-03 and NACA 4-(10)(08)-03 blade designs were made in the Langley 8-foot high-speed tunnel through a range of blade angle from 20 degrees to 60 degrees for forward Mach numbers from 0.165 to 0.70 to determine the effect of camber and compressibility on propeller characteristics. Results previously reported for similar tests of a two-blade propeller having the NACA 4-(3)(08)-03 blade design are included for comparison.

Very High-Speed Digital Video Capability for In-Flight Use

NASA Technical Reports Server (NTRS)

Corda, Stephen; Tseng, Ting; Reaves, Matthew; Mauldin, Kendall; Whiteman, Donald

2006-01-01

digital video camera system has been qualified for use in flight on the NASA supersonic F-15B Research Testbed aircraft. This system is capable of very-high-speed color digital imaging at flight speeds up to Mach 2. The components of this system have been ruggedized and shock-mounted in the aircraft to survive the severe pressure, temperature, and vibration of the flight environment. The system includes two synchronized camera subsystems installed in fuselage-mounted camera pods (see Figure 1). Each camera subsystem comprises a camera controller/recorder unit and a camera head. The two camera subsystems are synchronized by use of an MHub(TradeMark) synchronization unit. Each camera subsystem is capable of recording at a rate up to 10,000 pictures per second (pps). A state-of-the-art complementary metal oxide/semiconductor (CMOS) sensor in the camera head has a maximum resolution of 1,280 1,024 pixels at 1,000 pps. Exposure times of the electronic shutter of the camera range from 1/200,000 of a second to full open. The recorded images are captured in a dynamic random-access memory (DRAM) and can be downloaded directly to a personal computer or saved on a compact flash memory card. In addition to the high-rate recording of images, the system can display images in real time at 30 pps. Inter Range Instrumentation Group (IRIG) time code can be inserted into the individual camera controllers or into the M-Hub unit. The video data could also be used to obtain quantitative, three-dimensional trajectory information. The first use of this system was in support of the Space Shuttle Return to Flight effort. Data were needed to help in understanding how thermally insulating foam is shed from a space shuttle external fuel tank during launch. The cameras captured images of simulated external tank debris ejected from a fixture mounted under the centerline of the F-15B aircraft. Digital video was obtained at subsonic and supersonic flight conditions, including speeds up to Mach 2

Visual control of flight speed in Drosophila melanogaster.

PubMed

Fry, Steven N; Rohrseitz, Nicola; Straw, Andrew D; Dickinson, Michael H

2009-04-01

Flight control in insects depends on self-induced image motion (optic flow), which the visual system must process to generate appropriate corrective steering maneuvers. Classic experiments in tethered insects applied rigorous system identification techniques for the analysis of turning reactions in the presence of rotating pattern stimuli delivered in open-loop. However, the functional relevance of these measurements for visual free-flight control remains equivocal due to the largely unknown effects of the highly constrained experimental conditions. To perform a systems analysis of the visual flight speed response under free-flight conditions, we implemented a 'one-parameter open-loop' paradigm using 'TrackFly' in a wind tunnel equipped with real-time tracking and virtual reality display technology. Upwind flying flies were stimulated with sine gratings of varying temporal and spatial frequencies, and the resulting speed responses were measured from the resulting flight speed reactions. To control flight speed, the visual system of the fruit fly extracts linear pattern velocity robustly over a broad range of spatio-temporal frequencies. The speed signal is used for a proportional control of flight speed within locomotor limits. The extraction of pattern velocity over a broad spatio-temporal frequency range may require more sophisticated motion processing mechanisms than those identified in flies so far. In Drosophila, the neuromotor pathways underlying flight speed control may be suitably explored by applying advanced genetic techniques, for which our data can serve as a baseline. Finally, the high-level control principles identified in the fly can be meaningfully transferred into a robotic context, such as for the robust and efficient control of autonomous flying micro air vehicles.

NACA Aircraft on Lakebed - D-558-2, X-1B, and X-1E

NASA Technical Reports Server (NTRS)

1955-01-01

Early NACA research aircraft on the lakebed at the High Speed Research Station in 1955: Left to right: X-1E, D-558-2, X-1B There were four versions of the original Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the speed of sound, reaching about 700 miles per hour (Mach 1.06) and an altitude of 43,000 feet. The number 2 X-1 was modified and redesignated the X-1E. The modifications included adding a conventional canopy, an ejection seat, a low-pressure fuel system

Multivariable Techniques for High-Speed Research Flight Control Systems

NASA Technical Reports Server (NTRS)

Newman, Brett A.

1999-01-01

This report describes the activities and findings conducted under contract with NASA Langley Research Center. Subject matter is the investigation of suitable multivariable flight control design methodologies and solutions for large, flexible high-speed vehicles. Specifically, methodologies are to address the inner control loops used for stabilization and augmentation of a highly coupled airframe system possibly involving rigid-body motion, structural vibrations, unsteady aerodynamics, and actuator dynamics. Design and analysis techniques considered in this body of work are both conventional-based and contemporary-based, and the vehicle of interest is the High-Speed Civil Transport (HSCT). Major findings include: (1) control architectures based on aft tail only are not well suited for highly flexible, high-speed vehicles, (2) theoretical underpinnings of the Wykes structural mode control logic is based on several assumptions concerning vehicle dynamic characteristics, and if not satisfied, the control logic can break down leading to mode destabilization, (3) two-loop control architectures that utilize small forward vanes with the aft tail provide highly attractive and feasible solutions to the longitudinal axis control challenges, and (4) closed-loop simulation sizing analyses indicate the baseline vane model utilized in this report is most likely oversized for normal loading conditions.

Evaluation of High-Speed Civil Transport Handling Qualities Criteria with Supersonic Flight Data

NASA Technical Reports Server (NTRS)

Cox, Timothy H.; Jackson, Dante W.

1997-01-01

Most flying qualities criteria have been developed from data in the subsonic flight regime. Unique characteristics of supersonic flight raise questions about whether these criteria successfully extend into the supersonic flight regime. Approximately 25 years ago NASA Dryden Flight Research Center addressed this issue with handling qualities evaluations of the XB-70 and YF-12. Good correlations between some of the classical handling qualities parameters, such as the control anticipation parameter as a function of damping, were discovered. More criteria have been developed since these studies. Some of these more recent criteria are being used in designing the High-Speed Civil Transport (HSCT). A second research study recently addressed this issue through flying qualities evaluations of the SR-71 at Mach 3. The research goal was to extend the high-speed flying qualities experience of large airplanes and to evaluate more recent MIL-STD-1797 criteria against pilot comments and ratings. Emphasis was placed on evaluating the criteria used for designing the HSCT. XB-70 and YF-12 data from the previous research supplemented the SR-71 data. The results indicate that the criteria used in the HSCT design are conservative and should provide good flying qualities for typical high-speed maneuvering. Additional results show correlation between the ratings and comments and criteria for gradual maneuvering with precision control. Correlation is shown between ratings and comments and an extension of the Neal/Smith criterion using normal acceleration instead of pitch rate.

Cooling Tests of an Airplane Equipped with an NACA Cowling and a Wing-duct Cooling System

NASA Technical Reports Server (NTRS)

Turner, L I , Jr; Bierman, David; Boothy, W B

1941-01-01

Cooling tests were made of a Northrop A-17A attack airplane successively equipped with a conventional.NACA cowling and with a wing-duct cooling system. The method of cooling the engine by admitting air from the propeller slipstream into wing ducts, passing it first through the accessory compartment and then over the engine from rear to front, appeared to offer possibilities for improved engine cooling, increased cooling of the accessories, and better fairing of the power-plant installation. The results showed that ground cooling for the wing duct system without cowl flap was better than for the NACA cowling with flap; ground cooling was appreciably improved by installing a cowl flap. Satisfactory temperatures were maintained in both climb and high-speed flight, but, with the use of conventional baffles, a greater quantity of cooling air appeared to be required for the wing duct system.

78 FR 19981 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection: High Speed...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-03

...; Flight Envelope Protection: High Speed Limiting AGENCY: Federal Aviation Administration (FAA), DOT... protection: high speed limiting. As published, the document contained an error in that the Special Conditions...

Aerodynamic Characteristics of a Two-blade NACA 10-(3)(062)-045 Propeller and of a Two-blade NACA 10-(3)(08)-045 Propeller

NASA Technical Reports Server (NTRS)

Solomon, William

1953-01-01

Characteristics are given for the two-blade NACA 10-(3)(062)-045 propeller and for the two-blade NACA 10-(3)(08)-045 propeller over a range of advance ratio from 0.5 to 3.8, through a blade-angle range from 20 degrees to 55 degrees measured at the 0.75 radius. Maximum efficiencies of the order of 91.5 to 92 percent were obtained for the propellers. The propeller with the thinner airfoil sections over the outboard portion of the blades, the NACA 10-(3)(062)-045 propeller, had lower losses at high tip speeds, the difference amounting to about 5 percent at a helical tip Mach number of 1.10.

Flight motor modulation with speed in the hawkmoth Manduca sexta.

PubMed

Hedrick, Tyson L; Martínez-Blat, Jorge; Goodman, Mariah J

2017-01-01

The theoretical underpinnings for flight, including animal flight with flapping wings, predict a curvilinear U-shaped or J-shaped relationship between flight speed and the power required to maintain that speed. Experimental data have confirmed this relationship for a variety of bird and bat species but not insects, possibly due to differences in aerodynamics and physiology or experimental difficulties. Here we quantify modulation of the main flight motor muscles (the dorsolongitudinal and dorsoventral) via electromyography in hawkmoths (Manduca sexta) flying freely over a range of speeds in a wind tunnel and show that these insects exhibit a U-shaped speed-power relationship, with a minimum power speed of 2ms -1 , indicating that at least large flying insects achieve sufficiently high flight speeds that drag and power become limiting factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

A crew-centered flight deck design philosophy for High-Speed Civil Transport (HSCT) aircraft

NASA Technical Reports Server (NTRS)

Palmer, Michael T.; Rogers, William H.; Press, Hayes N.; Latorella, Kara A.; Abbott, Terence S.

1995-01-01

Past flight deck design practices used within the U.S. commercial transport aircraft industry have been highly successful in producing safe and efficient aircraft. However, recent advances in automation have changed the way pilots operate aircraft, and these changes make it necessary to reconsider overall flight deck design. The High Speed Civil Transport (HSCT) mission will likely add new information requirements, such as those for sonic boom management and supersonic/subsonic speed management. Consequently, whether one is concerned with the design of the HSCT, or a next generation subsonic aircraft that will include technological leaps in automated systems, basic issues in human usability of complex systems will be magnified. These concerns must be addressed, in part, with an explicit, written design philosophy focusing on human performance and systems operability in the context of the overall flight crew/flight deck system (i.e., a crew-centered philosophy). This document provides such a philosophy, expressed as a set of guiding design principles, and accompanied by information that will help focus attention on flight crew issues earlier and iteratively within the design process. This document is part 1 of a two-part set.

X-4 in flight

NASA Technical Reports Server (NTRS)

1951-01-01

speeds. Data generated during the initial flight led to design changes that improved handling and performance. While the first aircraft underwent modifications, the second X-4 arrived at Muroc in early 1949. Heavy rains flooded the dry lakebed at Muroc, delaying further flight testing until 27 April. The first X-4 made a few more flights, but was beset by mechanical problems. Soon, the second aircraft became the workhorse of the contractor test program. Its first flight was accomplished on 7 June 1949. It was more completely instrumented than its stablemate, and didn't suffer from the same plague of malfunctions. The National Advisory Committee for Aeronautics (NACA) expressed interest in using the second X-4 for research, but was frustrated by the slow pace of the contractor's test phase. Both X-4 aircraft were grounded temporarily for installation of spin recovery parachutes, and improvements to the landing gear uplock system. After these tasks were completed, the first X-4 made its tenth and final flight on 26 January 1950. It was grounded, and used as a source of spare parts for the second aircraft. On 17 February, the remaining X-4 completed the contractor testing phase. The aircraft was then turned over to the NACA and the Air Force for a joint research program. NACA technicians prepared the aircraft, and made a number of design improvements. The joint NACA/USAF program consisted of 82 flights to evaluate handling qualities, stability and control, and performance at various lift-to-drag ratios. NACA pilots during the program included Stanley Butchart, George Cooper, Scott Crossfield, John Griffith, Walter Jones, John 'Jack' McKay, and Joe Walker. The Air Force pilots included B/Gen. Albert Boyd, Col. Frank 'Pete' Everest, Lt. Col. Richard Johnson, Capt. J. S. Nash, and Maj. Charles 'Chuck' Yeager. The final X-4 flight took place in September 1953. Further flights were planned, but a chronic fuel leak lead to cancellation of the program. NACA engineers had acquired

NACA Pilots at the Aircraft Engine Research Laboratory

NASA Image and Video Library

1945-07-21

The Aircraft Engine Research Laboratory’s pilot corps during the final days of World War II: from left to right, Joseph Vensel, Howard Lilly, William Swann, and Joseph Walker. William “Eb” Gough joined the group months after this photograph. These men were responsible for flying the various National Advisory Committee for Aeronautics (NACA) aircraft to test new engine modifications, study ice buildup, and determine fuel performance. Vensel, a veteran pilot from Langley, was the Chief of Flight Operations and a voice of reason at the laboratory. In April 1947 Vensel was transferred to lead the new Muroc Flight Tests Unit in California until 1966. Lilly was a young pilot with recent Navy experience. Lilly also flew in the 1946 National Air Races. He followed Vensel to Muroc in July 1947 where he became the first NACA pilot to penetrate the sound barrier. On May 3, 1948, Lilly became the first NACA pilot to die in the line of duty. Swann was a young civilian pilot when he joined the NACA. He spent his entire career at the Cleveland laboratory, and led the flight operations group from the early 1960s until 1979. Two World War II veterans joined the crew after the war. Walker was a 24-year-old P–38 reconnaissance pilot. He joined the NACA as a physicist in early 1945 but soon worked his way into the cadre of pilots. Walker later gained fame as an X-plane pilot at Muroc and was killed in a June 1966 fatal crash. Gough survived being shot down twice during the war and was decorated for flying rescue missions in occupied areas.

Investigation of a Systematic Group of NACA 1-Series Cowlings with and Without Spinners

NASA Technical Reports Server (NTRS)

Nichols, Mark R; Keith, Arvid L , Jr

1949-01-01

Report presents the results of an investigation conducted in the Langley propeller research tunnel to study cowling-spinner combinations based on the NACA 1-series nose inlets and to obtain systematic design data for one family of approximately ellipsoidal spinners. In the main part of the investigation, 11 of the related spinners were tested in various combinations with 9 NACA open-nose cowlings, which were also tested without spinners. The effects of location and shape of the spinner, shape of the inner surface of the cowling lip, and operation of a propeller having approximately oval shanks were investigated briefly. In addition, a study was conducted to determine the correct procedure for extrapolating design conditions determined from the low-speed test data to the design conditions at the actual flight Mach number.

NACA Computer at the Lewis Flight Propulsion Laboratory

NASA Image and Video Library

1951-02-21

A female computer at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory with a slide rule and Friden adding machine to make computations. The computer staff was introduced during World War II to relieve short-handed research engineers of some of the tedious computational work. The Computing Section was staffed by “computers,” young female employees, who often worked overnight when most of the tests were run. The computers obtained test data from the manometers and other instruments, made the initial computations, and plotted the data graphically. Researchers then analyzed the data and summarized the findings in a report or made modifications and ran the test again. There were over 400 female employees at the laboratory in 1944, including 100 computers. The use of computers was originally planned only for the duration of the war. The system was so successful that it was extended into the 1960s. The computers and analysts were located in the Altitude Wind Tunnel Shop and Office Building office wing during the 1940s and transferred to the new 8- by 6-Foot Supersonic Wind Tunnel in 1948.

X-1A in flight with flight data superimposed

NASA Technical Reports Server (NTRS)

1953-01-01

for heat transfer research while the X-1C was intended as a high-speed armament systems test bed. All of these aircraft like the original X-1s, were launched from a Boeing B-29 or Boeing B-50 'mothership' to take maximum advantage of their limited flying time with a rocket engine. Most launches were made from the JTB-29A (45-21800). The other launch aircraft was EB-50A (46-006). X-1A The Bell X-1A was similar to the Bell X-1, except for having turbo-driven fuel pumps (instead of a system using nitrogen under pressure), a new cockpit canopy, longer fuselage and increased fuel capacity. The X-1A arrived at Edwards Air Force Base, California on January 7, 1953, with the first glide flight being successfully completed by Bell pilot, Jean 'Skip' Ziegler. The airplane also made five powered flights with Ziegler at the controls. The USAF was attempting a Mach 2 flight and USAF test pilot Charles 'Chuck' Yeager was eager. He reached speed of Mach 2.435, at a altitude of 75,000 feet on December 12, 1953, a speed record at the time. But all was not well, the aircraft encountered an inertial coupling phenomenon and went out of control. Once the X-1A had entered the denser atmosphere (35,000 feet) it slowly stabilized and Yeager was able to return to Edwards. The aircraft had experienced high-speed roll-coupling, something aerodynamicists had predicted, but this was the first actual encounter. On August 26, 1954, Major Arthur Murray, USAF test pilot flew the X-1A to an altitude record of 90,440 feet. NACA High-Speed Flight Station received the aircraft in September 1954 and returned it to Bell for the installation of an ejection seat. NACA test pilot Joseph Walker made a familiarization flight on July 20, 1955 followed by another scheduled flight on August 8, 1955. Shortly before launch the X-1A suffered an explosion. The extent of the damage prohibited landing the crippled aircraft. The X-1A was jettisoned into the desert, exploding and burning on impact. Walker and the B-29

The Effects of a Highly Cambered Low-Drag Wing and of Auxiliary Flaps on the High-Speed Aerodynamic Characteristics of a Twin-Engine Pursuit Airplane Model

NASA Technical Reports Server (NTRS)

Ganzer, Victor M

1944-01-01

Results are presented for tests of two wings, an NACA 230-series wing and a highly-cambered NACA 66-series wing on a twin-engine pursuit airplane. Auxiliary control flaps were tested in combinations with each wing. Data showing comparison of high-speed aerodynamic characteristics of the model when equipped with each wing, the effect of the auxiliary control flaps on aerodynamic characteristics, and elevator effectiveness for the model with the 66-series wing are presented. High-speed aerodynamic characteristics of the model were improved with the 66-series wing.

Vultee YA–31C Vengeance at the NACA

NASA Image and Video Library

1945-03-21

A Bell P-39 Airacobra in the NACA Aircraft Engine Research Laboratory’s Icing Research Tunnel for a propeller deicing study. The tunnel, which began operation in June 1944, was built to study the formation of ice on aircraft surfaces and methods of preventing or eradicating that ice. Ice buildup adds extra weight to aircraft, effects aerodynamics, and sometimes blocks airflow through engines. NACA design engineers added the Icing Research Tunnel to the new AERL’s original layout to take advantage of the massive refrigeration system being constructed for the Altitude Wind Tunnel. The Icing Research Tunnel is a closed-loop atmospheric wind tunnel with a 6- by 9-foot test section. The tunnel can produce speeds up to 300 miles per hour and temperatures from about 30 to -45⁰ F. During World War II AERL researchers analyzed different ice protection systems for propeller, engine inlets, antennae, and wings in the icing tunnel. The P-39 was a vital low-altitude pursuit aircraft of the US during the war. NACA investigators investigated several methods of preventing ice buildup on the P-39’s propeller, including the use of internal and external electrical heaters, alcohol, and hot gases. They found that continual heating of the blades expended more energy than the aircraft could supply, so studies focused on intermittent heating. The results of the wind tunnel investigations were then compared to actual flight tests on aircraft.

John B. McKay after X-15 flight #3-27-44

NASA Image and Video Library

1964-03-13

John B. McKay was one of the first pilots assigned to the X-15 flight research program at NASA's Flight Research Center, Edwards, Calif. As a civilian research pilot and aeronautical engineer, he made 30 flights in X-15s from October 28, 1960, until September 8, 1966. His peak altitude was 295,600 feet, and his highest speed was 3863 mph (Mach 5.64). McKay was with the NACA and NASA from February 8,1951 until October 5, 1971 and specialized in high-speed flight research programs. He began as an NACA intern, but assumed pilot status on July 11, 1952. In addition to the X-l5, he flew such experimental aircraft as the D-558-1, D-558-2, X-lB, and the X-lE. He has also served as a research pilot on flight programs involving the F-100, F-102, F-104, and the F-107. Born on December 8, 1922, in Portsmouth, Va., McKay graduated from Virginia Polytechnic Institute in 195O with a Bachelor of Science degree in Aeronautical Engineering. During World War II he served as a Navy pilot in the Pacific Theater, earning the Air Medal and Two Clusters, and a Presidential Unit Citation. McKay wrote several technical papers, and was a member of the American Institute of Aeronautics and Astronautics, as well as the Society of Experimental Test Pilots. He passed away on April 27, 1975.

Human engineering analysis for the high speed civil transport flight deck

NASA Technical Reports Server (NTRS)

Regal, David M.; Alter, Keith W.

1993-01-01

The Boeing Company is investigating the feasibility of building a second generation supersonic transport. If current studies support its viability, this airplane, known as the High Speed Civil Transport (HSCT), could be launched early in the next century. The HSCT will cruise at Mach 2.4, be over 300 feet long, have an initial range of between 5000 and 6000 NM, and carry approximately 300 passengers. We are presently involved in developing an advanced flight deck for the HSCT. As part of this effort we are undertaking a human engineering analysis that involves a top-down, mission driven approach that will allow a systematic determination of flight deck functional and information requirements. The present paper describes this work.

The Road to Mach 10: A History of the X-43A Hypersonic Flight Test Program at NASA Dryden -- Origins to First Flight

NASA Technical Reports Server (NTRS)

Peebles, Curtis

2006-01-01

The NASA Dryden Flight Research Center, in partnership with the NASA Langley Research Center and industrial contractors, conducted the first flight tests of a supersonic combustion ramjet (scramjet) in 2004. This was a revolutionary airbreathing engine able to operate at speeds above Mach 5, which carries potential for both high-speed atmospheric flight and as a space launcher. For the Dryden engineers, the X-43 program was the culmination of a nearly 60-year history of flight research, going back to the early days of supersonic flight, and to rocket planes such as the X-1, D-558-II Skyrocket, and the X-15. For the propulsion community, it marked a turning point in a quest that had taken nearly as long. The scramjet engine did not arise from the work of a single individual or from a single technological breakthrough. It evolved instead from work under way on ramjets in the early 1950s, and from research programs at the National Advisory Committee for Aeronautics (NACA) Lewis Research Center, at the U.S. Army Aberdeen Proving Ground, and by the U.S. Navy. Studies developed in the course of these disparate projects raised the possibility of supersonic combustion. Many researchers had considered the notion impractical due to the difficulty of stabilizing a flame front in a supersonic airflow. NACA researchers at Lewis attempted to test the idea's feasibility by burning aluminum borohydride in a supersonic wind tunnel. Sustained burning was believed to have been observed at Mach 1.5, Mach 2, and Mach 3 for as long as two seconds.

Flight Speeds among Bird Species: Allometric and Phylogenetic Effects

PubMed Central

Alerstam, Thomas; Rosén, Mikael; Bäckman, Johan; Ericson, Per G. P; Hellgren, Olof

2007-01-01

Flight speed is expected to increase with mass and wing loading among flying animals and aircraft for fundamental aerodynamic reasons. Assuming geometrical and dynamical similarity, cruising flight speed is predicted to vary as (body mass)1/6 and (wing loading)1/2 among bird species. To test these scaling rules and the general importance of mass and wing loading for bird flight speeds, we used tracking radar to measure flapping flight speeds of individuals or flocks of migrating birds visually identified to species as well as their altitude and winds at the altitudes where the birds were flying. Equivalent airspeeds (airspeeds corrected to sea level air density, U e) of 138 species, ranging 0.01–10 kg in mass, were analysed in relation to biometry and phylogeny. Scaling exponents in relation to mass and wing loading were significantly smaller than predicted (about 0.12 and 0.32, respectively, with similar results for analyses based on species and independent phylogenetic contrasts). These low scaling exponents may be the result of evolutionary restrictions on bird flight-speed range, counteracting too slow flight speeds among species with low wing loading and too fast speeds among species with high wing loading. This compression of speed range is partly attained through geometric differences, with aspect ratio showing a positive relationship with body mass and wing loading, but additional factors are required to fully explain the small scaling exponent of U e in relation to wing loading. Furthermore, mass and wing loading accounted for only a limited proportion of the variation in U e. Phylogeny was a powerful factor, in combination with wing loading, to account for the variation in U e. These results demonstrate that functional flight adaptations and constraints associated with different evolutionary lineages have an important influence on cruising flapping flight speed that goes beyond the general aerodynamic scaling effects of mass and wing loading. PMID

Radiation safety aspects of commercial high-speed flight transportation

NASA Technical Reports Server (NTRS)

Wilson, John W.; Nealy, John E.; Cucinotta, Francis A.; Shinn, Judy L.; Hajnal, Ferenc; Reginatto, Marcel; Goldhagen, Paul

1995-01-01

High-speed commercial flight transportation is being studied for intercontinental operations in the 21st century, the projected operational characteristics for these aircraft are examined, the radiation environment as it is now known is presented, and the relevant health issues are discussed. Based on a critical examination of the data, a number of specific issues need to be addressed to ensure an adequate knowledge of the ionizing radiation health risks of these aircraft operations. Large uncertainties in our knowledge of the physical fields for high-energy neutrons and multiply-charged ion components need to be reduced. Improved methods for estimating risks in prenatal exposure need to be developed. A firm basis for solar flare monitoring and forecasting needs to be developed with means of exposure abatement.

Investigation of spoiler ailerons for use as speed brakes or glide-path controls on two NACA 65-series wings equipped with full-span slotted flaps

NASA Technical Reports Server (NTRS)

Fischel, Jack; Watson, James M

1951-01-01

A wind-tunnel investigation was made to determine the characteristics of spoiler ailerons used as speed brakes or glide-path controls on an NACA 65-210 wing and an NACA 65-215 wing equipped with full-span slotted flaps. Several plug aileron and retractable-aileron configurations were investigated on two wing models with the full-span flaps retracted and deflected. Tests were made at various Mach numbers between 0.13 and 0.71. The results of this investigation have indicated that the use of plug or retractable ailerons, either alone or in conjunction with wing flaps, as speed brakes or glide-path controls is feasible and very effective.

High speed research system study. Advanced flight deck configuration effects

NASA Technical Reports Server (NTRS)

Swink, Jay R.; Goins, Richard T.

1992-01-01

In mid-1991 NASA contracted with industry to study the high-speed civil transport (HSCT) flight deck challenges and assess the benefits, prior to initiating their High Speed Research Program (HSRP) Phase 2 efforts, then scheduled for FY-93. The results of this nine-month effort are presented, and a number of the most significant findings for the specified advanced concepts are highlighted: (1) a no nose-droop configuration; (2) a far forward cockpit location; and (3) advanced crew monitoring and control of complex systems. The results indicate that the no nose-droop configuration is critically dependent upon the design and development of a safe, reliable, and certifiable Synthetic Vision System (SVS). The droop-nose configuration would cause significant weight, performance, and cost penalties. The far forward cockpit location, with the conventional side-by-side seating provides little economic advantage; however, a configuration with a tandem seating arrangement provides a substantial increase in either additional payload (i.e., passengers) or potential downsizing of the vehicle with resulting increases in performance efficiencies and associated reductions in emissions. Without a droop nose, forward external visibility is negated and takeoff/landing guidance and control must rely on the use of the SVS. The technologies enabling such capabilities, which de facto provides for Category 3 all-weather operations on every flight independent of weather, represent a dramatic benefits multiplier in a 2005 global ATM network: both in terms of enhanced economic viability and environmental acceptability.

NACA Technician Cleans a Ramjet in 8- by 6-Foot Supersonic Wind Tunnel

NASA Image and Video Library

1950-04-21

A technician at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory cleans the pitot tube on a 16-inch diameter ramjet in the 8- by 6-Foot Supersonic Wind Tunnel. Pitot tubes are a measurement device used to determine the flow velocity at a specific location in the air stream, not the average velocity of the entire wind stream. NACA Lewis was in the midst of a multi-year program to determine the feasibility of ramjets and design improvements that could be employed for all models. The advantage of the ramjet was its ability to process large volumes of combustion air, resulting in the burning of fuel at the optimal stoichiometric temperatures. This was not possible with turbojets. The higher the Mach number, the more efficient the ramjet operated. The 8- by 6 Supersonic Wind Tunnel had been in operation for just over one year when this photograph was taken. The facility was the NACA’s largest supersonic tunnel and the only facility capable of running an engine at supersonic speeds. The 8- by 6 tunnel was also equipped with a Schlieren camera system that captured the air flow gradient as it passes over the test setup. The ramjet tests in the 8- by 6 tunnel complemented the NACA Lewis investigations using aircraft, the Altitude Wind Tunnel and smaller supersonic tunnels. Researchers studied the ramjet’s performance at different speeds and varying angles -of -attack.

Economy of flight at supersonic speeds

NASA Technical Reports Server (NTRS)

Jones, R. T.

1976-01-01

Prandtl's theory is used to determine the airflow over bodies and wings adapted to supersonic flight. By making use of these results, and by incorporating in them an allowance for the probable skin friction, some estimates of expected lift-drag ratios are made for various flight speeds with the best configuration. At each speed a slender body and wings having the best angle of sweepback are considered. For the range of supersonic speeds shown an airplane of normal density and loading would be required to operate at an altitude of the order of 60,000 feet. The limiting value of 1-1/2 times the speed of sound corresponds to a flight speed of 1000 miles per hour. At this speed about 1.5 miles per gallon of fuel are expected. It is interesting to note that this value corresponds to a value of more than 15 miles per gallon when the weight is reduced to correspond to that of an ordinary automobile.

Direct Evidence for Vision-based Control of Flight Speed in Budgerigars.

PubMed

Schiffner, Ingo; Srinivasan, Mandyam V

2015-06-05

We have investigated whether, and, if so, how birds use vision to regulate the speed of their flight. Budgerigars, Melopsittacus undulatus, were filmed in 3-D using high-speed video cameras as they flew along a 25 m tunnel in which stationary or moving vertically oriented black and white stripes were projected on the side walls. We found that the birds increased their flight speed when the stripes were moved in the birds' flight direction, but decreased it only marginally when the stripes were moved in the opposite direction. The results provide the first direct evidence that Budgerigars use cues based on optic flow, to regulate their flight speed. However, unlike the situation in flying insects, it appears that the control of flight speed in Budgerigars is direction-specific. It does not rely solely on cues derived from optic flow, but may also be determined by energy constraints.

Direct Evidence for Vision-based Control of Flight Speed in Budgerigars

PubMed Central

Schiffner, Ingo; Srinivasan, Mandyam V.

2015-01-01

We have investigated whether, and, if so, how birds use vision to regulate the speed of their flight. Budgerigars, Melopsittacus undulatus, were filmed in 3-D using high-speed video cameras as they flew along a 25 m tunnel in which stationary or moving vertically oriented black and white stripes were projected on the side walls. We found that the birds increased their flight speed when the stripes were moved in the birds’ flight direction, but decreased it only marginally when the stripes were moved in the opposite direction. The results provide the first direct evidence that Budgerigars use cues based on optic flow, to regulate their flight speed. However, unlike the situation in flying insects, it appears that the control of flight speed in Budgerigars is direction-specific. It does not rely solely on cues derived from optic flow, but may also be determined by energy constraints. PMID:26046799

High-Speed Tests of a Model Twin-Engine Low-Wing Transport Airplane

NASA Technical Reports Server (NTRS)

Becker, John V; LEONARD LLOYD H

1942-01-01

Report presents the results of force tests made of a 1/8-scale model of a twin-engine low-wing transport airplane in the NACA 8-foot high-speed tunnel to investigate compressibility and interference effects of speeds up to 450 miles per hour. In addition to tests of the standard arrangement of the model, tests were made with several modifications designed to reduce the drag and to increase the critical speed.

Some lessons from NACA/NASA aerodynamic studies following World War II

NASA Technical Reports Server (NTRS)

Spearman, M. L.

1983-01-01

An historical account is presented of the new departures in aerodynamic research conducted by NACA, and subsequently NASA, as a result of novel aircraft technologies and operational regimes encountered in the course of the Second World War. The invention and initial development of the turbojet engine furnished the basis for a new speed/altitude regime in which numerous aerodynamic design problems arose. These included compressibility effects near the speed of sound, with attendant lift/drag efficiency reductions and longitudinal stability enhancements that were accompanied by a directional stability reduction. Major research initiatives were mounted in the investigation of swept, delta, trapezoidal and variable sweep wing configurations, sometimes conducted through flight testing of the 'X-series' aircraft. Attention is also given to the development of the first generation of supersonic fighter aircraft.

D-558-I in flight

NASA Technical Reports Server (NTRS)

1957-01-01

The Douglas D-558-1 Skystreak is seen close-up in this early 1950s inflight photograph. Although less well known than the X-1, the D-558-1 could carry out research roles that complemented those of the more glamorous, rocket-powered craft. The D-558-1 was relatively slow, with only one flight exceeding a speed of Mach 1 (the speed of sound). However, the jet-powered Skystreak could fly for sustained periods at transonic speeds, increasing the amount of data a single flight could yield. By contrast, the rocket-powered X-1 could only provide transonic data for brief periods on each flight. Conceived in 1945, the D558-1 Skystreak was designed by the Douglas Aircraft Company for the U.S. Navy Bureau of Aeronautics, in conjunction with the National Advisory Committee for Aeronautics (NACA). The Skystreaks were turojet powered aircraft that took off from the ground under their own power and had straight wings and tails. All three D-558-1 Skystreaks were powered by Allison J35-A-11 turbojet engines producing 5,000 pounds of thrust. All the Skystreaks were initially painted scarlet, which lead to the nickname 'crimson test tube.' NACA later had the color of the Skystreaks changed to white to improve optical tracking and photography. The Skystreaks carried 634 pounds of instrumentation and were ideal first-generation, simple, transonic research airplanes. Much of the research performed by the D-558-1 Skystreaks, was quickly overshadowed in the public mind by Chuck Yeager and the X-1 rocketplane. However, the Skystreak performed an important role in aeronautical research by flying for extended periods of time at transonic speeds, which freed the X-1 to fly for limited periods at supersonic speeds.

Cavitation Characteristics of a NACA 63-424 Hydrofoil and Performance Comparison with a Bidirectional Version of the Foil

NASA Astrophysics Data System (ADS)

Nedyalkov, Ivaylo; Wosnik, Martin

2012-11-01

A NACA 63-424 hydrofoil with a 75 mm chord and a 152 mm span was tested in the recently renovated 6-inch high-speed water tunnel at the University of New Hampshire. The NACA 63-424 foil is being considered for use on rotors of marine hydrokinetic turbines, including the US Department of Energy Reference Horizontal Axis Turbine (RHAT) for tidal and ocean current applications. For various angles of attack, the foil was tested at speeds ranging from 2 m/s to 12 m/s. Pressure in the test section was varied independently. For each angle, speed and pressure setting, high speed videos were recorded (at 3600 frames per second and above). Cavitation inception and desinance were obtained. Lift and drag were measured using a new 2-component force balance. In tidal turbines applications, bidirectional foils do not require pitch control, hence the experiments were repeated for a bidirectional version of the NACA 63-424 foil and the characteristics of the two foils were compared. The results can be used to predict cavitation inception and performance of marine hydrokinetic turbines, for a given site, deployment depth and and tip speed ratio.

NACA Researcher Measures Ice on a Turbojet Engine Inlet

NASA Image and Video Library

1948-11-21

The National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory conducted an extensive icing research program in the late 1940s that included studies in the Icing Research Tunnel and using specially modified aircraft. One facet of this program was the investigation of the effects of icing on turbojets. Although jet engines allowed aircraft to pass through inclement weather at high rates of speed, ice accumulation was still a concern. The NACA’s B-24M Liberator was initially reconfigured with a General Electric I-16 engine installed in the aircraft’s waist compartment with an air scoop and spray nozzles to produce the artificial icing conditions. The centrifugal engine appeared nearly impervious to the effects of icing. Axial-flow jet engines, however, were much more susceptible to icing damage. The inlet guide vanes were particularly vulnerable, but the cowling’s leading edge, the main bearing supports, and accessory housing could also ice up. If pieces of ice reached the engine’s internal components, the compressor blades could be damaged. To study this phenomenon, a Westinghouse 24C turbojet, seen in this photograph, was installed under the B-24M’s right wing. In January 1948 flight tests of the 24C in icing conditions began. Despite ice buildup into the second stage of the compressor, the engine was able to operate at takeoff speeds. Researchers found the ice on the inlet vanes resulted in half of the engine’s decreased performance.

Rocket Research Presentation at the NACA's 1947 Inspection

NASA Image and Video Library

1947-10-21

Researcher John Sloop briefs visitors on his latest rocket engine research during the 1947 Inspection at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The NACA had been hosting annual Aircraft Engineering Conferences, better known as Inspections, since 1926. Individuals from the manufacturing industry, military, and university settings were invited to tour the NACA laboratories. There were a series of stops on the tour, mostly at test facilities, where researchers would brief the group on the latest efforts in their particular field. The Inspections grew in size and scope over the years and by the mid-1940s required multiple days. The three-day 1947 Inspection was the first time the event was held at NACA Lewis. Over 800 scientists, industrialists, and military leaders attended the three-day event. Talks were given at the Altitude Wind Tunnel, Four Burner Area, Engine Research Building, and other facilities. An array of topics were discussed, including full-scale engine testing, ramjets, axial-flow compressors, turbojets, fuels, icing, and materials. The NACA Lewis staff and their families were able to view the same presentations after the Inspection was over. Sloop, a researcher in the Fuels and Thermodynamics Division, briefed visitors on NACA Lewis’ early research in rocket engine propellants, combustion, and cooling. This early NACA Lewis work led to the development of liquid hydrogen as a viable propellant in the late 1950s.

Convective heat transfer measurements from a NACA 0012 airfoil in flight and in the NASA Lewis Icing Research Tunnel

NASA Technical Reports Server (NTRS)

Poinsatte, Philip E.; Vanfossen, G. James; Dewitt, Kenneth J.

1989-01-01

Local heat transfer coefficients were measured on a smooth and roughened NACA 0012 airfoil. Heat transfer measurements on the 0.533 m chord airfoil were made both in flight on the NASA Lewis Twin Otter Icing Research Aircraft and in the NASA Lewis Icing Research Tunnel (IRT). Roughness was obtained by the attachment of uniform 2 mm diameter hemispheres to the airfoil surface in 4 distinct patterns. Flight data were taken for the smooth and roughened airfoil at various Reynolds numbers based on chord in the range 1.24 to 2.50 x 10(exp 6) and at various angles of attack up to 4 deg. During these flight tests, the free stream velocity turbulence intensity was found to be very low (less than 0.1 percent). Wind tunnel data were acquired in the Reynolds number range 1.20 to 4.25 x 10(exp 6) and at angles of attack from -4 to 8 deg. The turbulence intensity in the IRT was 0.5 to 0.7 percent with the cloud generating sprays off. A direct comparison was made between the results obtained in flight and in the IRT. The higher level of turbulence in the IRT vs. flight had little effect on the heat transfer for the lower Reynolds numbers but caused a moderate increase in heat transfer at the high Reynolds numbers. Roughness generally increased the heat transfer.

NACA Subcommittee on Combustion Meeting

NASA Image and Video Library

1951-12-21

The National Advisory Committee for Aeronautics (NACA) Subcommittee on Combustion holds a meeting at Lewis Flight Propulsion Laboratory in Cleveland, Ohio. The NACA was managed by committees that included members of their own staff along with representatives from industry, the military, other government agencies, and universities. The 17-person Executive Committee was the NACA’s primary administrative body. They met several times a year at the NACA headquarters office in Washington DC to discuss broad issues confronting the US aeronautical community. Jerome Hunsaker, head of the Department of Aeronautical Engineering at the Massachusetts Institute of Technology, served as the NACA chairman from 1941 to 1956. George Lewis was not a member of the Executive Committee but served a key role as the NACA’s Director of Aeronautical Research. The NACA’s organizational chart also included 11 technical committees, several of which had specialized subcommittees. There were over 100 different subcommittees between World War I and 1958. The number of active subcommittees varied over the years. Most existed only for a few years, but some continued for over a decade. The subcommittees met three or four times per year, often at the laboratory most closely associated with the area of research. A team of laboratory researchers presented briefings on their recent activities and plans for the future. The Subcommittee on Combustion existed from 1945 to the NACA’s demise in 1958.

Prediction of ice accretion on a swept NACA 0012 airfoil and comparisons to flight test results

NASA Technical Reports Server (NTRS)

Reehorst, Andrew L.

1992-01-01

In the winter of 1989-90, an icing research flight project was conducted to obtain swept wing ice accretion data. Utilizing the NASA Lewis Research Center's DHC-6 DeHavilland Twin Otter aircraft, research flights were made into known icing conditions in Northeastern Ohio. The icing cloud environment and aircraft flight data were measured and recorded by an onboard data acquisition system. Upon entry into the icing environment, a 24 inch span, 15 inch chord NACA 0012 airfoil was extended from the aircraft and set to the desired sweep angle. After the growth of a well defined ice shape, the airfoil was retracted into the aircraft cabin for ice shape documentation. The ice accretions were recorded by ice tracings and photographs. Ice accretions were mostly of the glaze type and exhibited scalloping. The ice was accreted at sweep angles of 0, 30, and 45 degrees. A 3-D ice accretion prediction code was used to predict ice profiles for five selected flight test runs, which include sweep angle of zero, 30, and 45 degrees. The code's roughness input parameter was adjusted for best agreement. A simple procedure was added to the code to account for 3-D ice scalloping effects. The predicted ice profiles are compared to their respective flight test counterparts. This is the first attempt to predict ice profiles on swept wings with significant scalloped ice formations.

Groundbreaking Ceremony at the NACA's Plum Brook Station

NASA Image and Video Library

1956-09-21

Addison Rothrock, the National Advisory Committee for Aeronautics’s (NACA) Assistant Director of Research, speaks at the groundbreaking ceremony for the Lewis Flight Propulsion Laboratory’s new test reactor at Plum Brook Station. This dedication event was held almost exactly one year after the NACA announced that it would build its $4.5 million nuclear reactor on 500 acres of the army’s 9000-acre Plum Brook Ordnance Works. The site was located in Sandusky, Ohio, approximately 60 miles west of the NACA Lewis laboratory in Cleveland. Lewis Director Raymond Sharp is seated to the left of Rothrock, Congressman Albert Baumhart and NACA Secretary John Victory are to the right. Many government and local officials were on hand for the press conference and ensuing luncheon. In the wake of World War II the military, the Atomic Energy Commission, and the NACA became interested in the use of atomic energy for propulsion and power. A Nuclear Division was established at NACA Lewis in the early 1950s. The division’s request for a 60-megawatt research reactor was approved in 1955. The semi-remote Plum Brook location was selected over 17 other possible sites. Construction of the Plum Brook Reactor Facility lasted five years. By the time of its first trial runs in 1961 the aircraft nuclear propulsion program had been cancelled. The space age had arrived, however, and the reactor would be used to study materials for a nuclear powered rocket.

Rocket Propellant Talk at the 1957 NACA Lewis Inspection

NASA Image and Video Library

1957-10-21

A researcher works a demonstration board in the Rocket Engine Test Facility during the 1957 Inspection of the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory in Cleveland, Ohio. Representatives from the military, aeronautical industry, universities, and the press were invited to the laboratory to be briefed on the NACA’s latest research efforts and tour the test facilities. Over 1700 people visited the Lewis during the October 7-10, 1957 Inspection. The Soviet Union launched their first Sputnik satellite just days before on October 4. NACA Lewis had been involved in small rockets and propellants research since 1945, but the NACA leadership was wary of involving itself too deeply with the work since ballistics traditionally fell under the military’s purview. The Lewis research was performed by the High Temperature Combustion section in the Fuels and Lubricants Division in a series of small cinderblock test cells. The rocket group was expanded in 1952 and made several test runs in late 1954 using liquid hydrogen as a propellant. A larger test facility, the Rocket Engine Test Facility, was approved and became operational just in time for the Inspection.

Inner loop flight control for the High-Speed Civil Transport

NASA Technical Reports Server (NTRS)

Newman, Brett A.

1994-01-01

High-speed aerospace vehicles which employ high strength, light weight, yet deformable materials may exhibit significant interaction between the rigid-body and vibrational dynamics. Preliminary High-Speed Civil Transport (HSCT) configurations are a prime example. Traditionally, separate control systems have been used to augment the rigid-body and vibrational dynamics. In the HSCT arena, the highly coupled motions may not allow this design freedom. The research activity addresses two specific issues associated with the design and development of an integrated flight control system (FCS) for HSCT configurations, which are discussed next. The HSCT is expected to have a short period instability at subsonic speeds. Flight vehicles with this characteristic (i.e., F-16, F-22, X-29, Space Shuttle) are stabilized with what is called a superaugmented pitch rate loop. One concern is 'Will this stability augmentation logic work for a HSCT?' Studies show that an idealized pitch rate design would be acceptable, but is not realistic. Investigations using a contaminated pitch rate design reveal serious hurdles to overcome in the FCS design. Mounting location for the pitch rate sensor is critical. Results indicate a forward location leads to destabilizing pick-up of aeroelastic modes, while aft locations lead to undesirable coupling of the dominate pitch mode with the first aeroelastic mode. Intermediate locations for the sensor may not be acceptable. The source of the problem is the presence of low frequency aeroelastic modes in HSCT configurations, which are not present in vehicles currently using the superaugmented logic. To say the least, a conventional superaugmented pitch rate loop strategy may have undesirable characteristics. An unconventional strategy, which attempts to eliminate the above deficiencies by blending several pitch rate signals, indicates an improvement in the FCS architecture feasibility, but is still lacking in some respects. The HSCT configuration does not

Origin of Marshall Space Flight Center (MSFC)

NASA Image and Video Library

1960-07-01

The Marshall Space Flight Center was activated on July 1, 1960 as a part of NASA, which had been established on October 1, 1958 by Congressional passage of the National Aeronautics and Space Act. The nucleus of NASA was the Advisory Committee for Aeronautics later named the National Advisory Committee for Aeronauts (NACA). The NACA was founded in 1915 to study the problems of flight and to recommend practical solutions to basic aircraft design and construction problems. NACA's wind turnels and other research facilities made NACA technical reports the basis for aviation progress for more than 40 years.

Flight speed and performance of the wandering albatross with respect to wind.

PubMed

Richardson, Philip L; Wakefield, Ewan D; Phillips, Richard A

2018-01-01

in headwind than tailwind flight but only in wind speeds of up to ~ 7 m/s. Our models predict that wandering albatrosses have oval-shaped airspeed polars, with the fastest airspeeds ~ 20 m/s centered in the across-wind direction. This suggests that in upwind flight in high winds, albatrosses can increase their ground speed by tacking like sailboats.

Pressure Distribution Over Airfoils at High Speeds

NASA Technical Reports Server (NTRS)

Briggs, L J; Dryden, H L

1927-01-01

This report deals with the pressure distribution over airfoils at high speeds, and describes an extension of an investigation of the aerodynamic characteristics of certain airfoils which was presented in NACA Technical Report no. 207. The results presented in report no. 207 have been confirmed and extended to higher speeds through a more extensive and systematic series of tests. Observations were also made of the air flow near the surface of the airfoils, and the large changes in lift coefficients were shown to be associated with a sudden breaking away of the flow from the upper surface. The tests were made on models of 1-inch chord and comparison with the earlier measurements on models of 3-inch chord shows that the sudden change in the lift coefficient is due to compressibility and not to a change in the Reynolds number. The Reynolds number still has a large effect, however, on the drag coefficient. The pressure distribution observations furnish the propeller designer with data on the load distribution at high speeds, and also give a better picture of the air-flow changes.

Flight speed of tethered Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) alates

Treesearch

Thomas G. Shelton; X. Ping Hu; Arthur G. Appel; Terence L. Wagner

2006-01-01

Alates of the Eastern subterranean termite, Reticulitermes flavipes (Kollar) were collected over two flight seasons (2002 and 2004) and flown on flight mulls. Data were collected to test if alate mass, colony origin, or gender influenced flight speed. Flight speed ranged from 3.14 to 69.12 cm s-1 and the maximum distance flown...

A Study by High-Speed Photography of Combustion and Knock in a Spark-Ignition Engine

NASA Technical Reports Server (NTRS)

Miller, Cearcy D

1942-01-01

The study of combustion in a spark-ignition engine given in Technical Report no. 704 has been continued. The investigation was made with the NACA high-speed motion-picture camera and the NACA optical engine indicator. The camera operates at the rate of 40,000 photographs a second and makes possible the study of phenomena occurring in time intervals as short as 0.000025 second. Photographs are presented of combustion without knock and with both light and heavy knocks, the end zone of combustion being within the field of view. Time-pressure records covering the same conditions as the photographs are presented and their relations to the photographs are studied. Photographs with ignition at various advance angles are compared with a view to observing any possible relationship between pressure and flame depth. A tentative explanation of knock is suggested, which is designed to agree with the indications of the high-speed photographs and the time-pressure records.

Full-Scale Tests of NACA Cowlings

NASA Technical Reports Server (NTRS)

Theodorsen, Theodore; Brevoort, M J; Stickle, George W

1937-01-01

A comprehensive investigation has been carried on with full-scale models in the NACA 20-foot wind tunnel, the general purpose of which is to furnish information in regard to the physical functioning of the composite propeller-nacelle unit under all conditions of take-off, taxiing, and normal flight. This report deals exclusively with the cowling characteristics under condition of normal flight and includes the results of tests of numerous combinations of more than a dozen nose cowlings, about a dozen skirts, two propellers, two sizes of nacelle, as well as various types of spinners and other devices.

The SR-71 Test Bed Aircraft: A Facility for High-Speed Flight Research

NASA Technical Reports Server (NTRS)

Corda, Stephen; Moes, Timothy R.; Mizukami, Masashi; Hass, Neal E.; Jones, Daniel; Monaghan, Richard C.; Ray, Ronald J.; Jarvis, Michele L.; Palumbo, Nathan

2000-01-01

The SR-71 test bed aircraft is shown to be a unique platform to flight-test large experiments to supersonic Mach numbers. The test bed hardware mounted on the SR-71 upper fuselage is described. This test bed hardware is composed of a fairing structure called the "canoe" and a large "reflection plane" flat plate for mounting experiments. Total experiment weights, including the canoe and reflection plane, as heavy as 14,500 lb can be mounted on the aircraft and flight-tested to speeds as fast as Mach 3.2 and altitudes as high as 80,000 ft. A brief description of the SR-71 aircraft is given, including details of the structural modifications to the fuselage, modifications to the J58 engines to provide increased thrust, and the addition of a research instrumentation system. Information is presented based on flight data that describes the SR-71 test bed aerodynamics, stability and control, structural and thermal loads, the canoe internal environment, and reflection plane flow quality. Guidelines for designing SR-71 test bed experiments are also provided.

D-558-2 LOX (Liquid OXygen) jettison on ramp

NASA Technical Reports Server (NTRS)

1956-01-01

In this 1956 photograph the Douglas D-558-2 #1 is shown venting liquid oxigen (LOX). The photograph was taken in back of the NACA High-Speed Flight Station's new hangar and building on the main base at Edwards Air Force Base. The P2B-1S Superfortress (Navy version of the Air Force B-29) launch aircraft is parked in the background. The NACA acquired this aircraft on August 31, 1951, after Douglas had completed the contract flights. The Douglas plant later converted its powerplant to an all-rocket system that required launch from a mothership (the P2B-1S). Douglas returned the aircraft to the NACA on November 15, 1955. The High-Speed Flight Station intended to use it for tests of external stores at supersonic speeds. NACA research pilot John McKay made a single flight in the aircraft on September 17, 1956, but the NACA subsequently cancelled the program. The Douglas D-558-2 'Skyrockets' were among the early transonic research airplanes like the X-1, X-4, X-5, and X-92A. Three of the single-seat, swept-wing aircraft flew from 1948 to 1956 in a joint program involving the National Advisory Committee for Aeronautics (NACA), with its flight research done at the NACA's Muroc Flight Test Unit in Calif., redesignated in 1949 the High-Speed Flight Research Station (HSFRS). Also partners in the flight research were the Navy-Marine Corps and the Douglas Aircraft Co. The HSFRS became the High-Speed Flight Station in 1954 and is now known as the NASA Dryden Flight Research Center. The Skyrocket made aviation history when it became the first airplane to fly twice the speed of sound. The 2 in the aircraft's designation referred to the fact that the Skyrocket was the phase-two version of what had originally been conceived as a three-phase program, with the phase-one aircraft having straight wings. The third phase, which never came to fruition, would have involved constructing a mock-up of a combat-type aircraft embodying the results from the testing of the phase one and two

X-1A in flight over lakebed

NASA Technical Reports Server (NTRS)

1953-01-01

The Bell Aircraft Corporation X-1A (48-1384) returning from an Air Force test flight over Edwards Air Force Base, California in late 1953. A North American F-86A Sabre as chase plane will follow the X-1A to touchdown. The Rogers Dry Lake is the whitish area under the planes with the airfield at the edge of the dry lake. Bell test pilot Jean 'Skip' Ziegler made six flights between 14 February and 25 April 1953. Air Force test pilots Maj. Charles 'Chuck' Yeager and Maj. Arthur 'Kit' Murray made 18 test flights between 21 November 1953 and 26 August 1954. NACA test pilot Joseph Walker made one successful flight on 20 July 1955. During a second flight attempt, on 8 August 1955, an explosion damaged the aircraft shortly before launch. Walker, unhurt, climbed up into the JTB-29A mothership, and the X-1A was jettisoned over the Edwards AFB bombing range. There were five versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system

NACA Engineer Examines Wind Tunnel Compressor Blades

NASA Image and Video Library

1955-09-21

An engineer examines the main compressor for the 10- by 10-Foot Supersonic Wind Tunnel at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The engineers were preparing the new wind tunnel for its initial runs in early 1956. The 10- by 10 was the most powerful propulsion wind tunnel in the nation. The facility was part of Congress’ Unitary Plan Act which coordinated wind tunnel construction at the NACA, Air Force, industry, and universities. The 10- by 10 was the largest of the three NACA tunnels built under the act. The 20-foot diameter eight-stage axial flow compressor, seen in this photograph, could generate air flows up to Mach 2.5 through the test section. The stainless steel compressor had 584 blades ranging from 1.8 to 3.25 feet in length. This main compressor was complemented by a secondary axial flow compressor. Working in tandem the two could generate wind streams up to Mach 3.5. The Cleveland Chamber of Commerce presented NACA Lewis photographer Bill Bowles with a second place award for this photograph in their Business and Professional category. The photograph was published in October 1955 edition of its periodical, The Clevelander, which highlighted local professional photographers. Fellow Lewis photographer Gene Giczy won second place in another category for a photograph of Cleveland Municipal Airport.

Airplane tracking documents the fastest flight speeds recorded for bats.

PubMed

McCracken, Gary F; Safi, Kamran; Kunz, Thomas H; Dechmann, Dina K N; Swartz, Sharon M; Wikelski, Martin

2016-11-01

The performance capabilities of flying animals reflect the interplay of biomechanical and physiological constraints and evolutionary innovation. Of the two extant groups of vertebrates that are capable of powered flight, birds are thought to fly more efficiently and faster than bats. However, fast-flying bat species that are adapted for flight in open airspace are similar in wing shape and appear to be similar in flight dynamics to fast-flying birds that exploit the same aerial niche. Here, we investigate flight behaviour in seven free-flying Brazilian free-tailed bats ( Tadarida brasiliensis ) and report that the maximum ground speeds achieved exceed speeds previously documented for any bat. Regional wind modelling indicates that bats adjusted flight speeds in response to winds by flying more slowly as wind support increased and flying faster when confronted with crosswinds, as demonstrated for insects, birds and other bats. Increased frequency of pauses in wing beats at faster speeds suggests that flap-gliding assists the bats' rapid flight. Our results suggest that flight performance in bats has been underappreciated and that functional differences in the flight abilities of birds and bats require re-evaluation.

Wind Tunnel Tests of Ailerons at Various Speeds I : Ailerons of 0.20 Airfoil Chord and True Contour with 0.35 Aileron-chord Extreme Blunt Nose Balance on the NACA 66,2-216 Airfoil

NASA Technical Reports Server (NTRS)

Letko, W; Denaci, H. G.; Freed, C

1943-01-01

Hinge-moment, lift, and pressure-distribution measurements were made in the two-dimensional test section of the NACA stability tunnel on a blunt-nose balance-type aileron on an NACA 66,2-216 airfoil at speeds up to 360 miles per hour corresponding to a Mach number of 0.475. The tests were made primarily to determine the effect of speed on the action of this type of aileron. The balance-nose radii of the aileron were varied from 0 to 0.02 of the airfoil chord and the gap width was varied from 0.0005 to 0.0107 of the airfoil chord. Tests were also made with the gap sealed.

Experiments on high speed ejectors

NASA Technical Reports Server (NTRS)

Wu, J. J.

1986-01-01

Experimental studies were conducted to investigate the flow and the performance of thrust augmenting ejectors for flight Mach numbers in the range of 0.5 to 0.8, primary air stagnation pressures up to 107 psig (738 kPa), and primary air stagnation temperatures up to 1250 F (677 C). The experiment verified the existence of the second solution ejector flow, where the flow after complete mixing is supersonic. Thrust augmentation in excess of 1.2 was demonstrated for both hot and cold primary jets. The experimental ejector performed better than the corresponding theoretical optimal first solution ejector, where the mixed flow is subsonic. Further studies are required to realize the full potential of the second solution ejector. The research program was started by the Flight Dynamics Research Corporation (FDRC) to investigate the characteristic of a high speed ejector which augments thrust of a jet at high flight speeds.

Northrop P-61 Black Widow Flight Testing a Ramjet

NASA Image and Video Library

1947-01-21

The National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory obtained a Northrop P-61 Black Widow in October 1945 and modified it to serve as a subsonic testbed for ramjet engines and swept-wing aircraft models. The P-61 was developed during World War II specifically for nighttime attacks. It was the largest and heaviest US fighter in the war. The P-61’s unique design included an abbreviated fuselage and twin booms that were joined by a single tail. To facilitate its nighttime missions, the P-61 was painted black and carried a radar system in its nose. It was designed so the crew could perform their flight and tracking tasks in complete darkness. NACA Lewis was in the midst of a massive research effort on ramjets when it acquired the Black Widow. Researchers used the aircraft to accelerate the ramjet until it reached a velocity at which it could be ignited. A ramjet can be seen being fired underneath the aircraft in this photograph. Sensors and instrumentation fed data from the ramjet to the pilot and researchers on the ground. The NACA researchers created a rectangular ramjet with a V-shaped gutter flameholder. The researchers installed the ramjet on the P-61 and flew it at subsonic speeds over a range of altitudes up to 29,000 feet. The ramjet had been previously tested at low speeds on a test stand on the hangar apron. The rectangular ramjet was also used to study different types of flameholders and nozzles used to spray fuel into the combustion chamber. The Black Widow was transferred from Lewis in October 1948.

Walter C. Williams

NASA Technical Reports Server (NTRS)

1949-01-01

Walter C. Williams arrived from the National Advisory Committee for Aeronautics, Langley Memorial Aeronautical Laboratory, Hampton, Virginia, on September 30, 1946, at the Muroc Army Air Field. He had been named the engineer-in-charge of the small group of five that came with him to the Rogers Dry Lakebed to take part in research flights of a joint NACA-Army Air Forces program involving the rocket-powered Bell XS-1. This established the first permanent National Advisory Committee for Aeronautics presence at the Mojave Desert site in California. This small group grew in numbers to 27 and received permanent status as the NACA Muroc Flight Test Unit from Hugh L. Dryden, NACA's Director of Research, on September 27, 1947. Walt was named Head of the Unit. On November 14, 1949, the Unit along with the 100 employees became the NACA High-Speed Flight Research Station with Walt Williams as Chief. Next came the move from the South Base site to the new headquarters, Bldg. 4800 on the north-west shore of the Rogers Dry lakebed on the Edwards Air Force Base complex. July 1, 1954 saw another name change to the NACA High-Speed Flight Station with Walt remaining the Chief to a complement of about 225 employees. Williams had received a Bachelor of Science Degree in aeronautical engineering from Louisiana State University, Baton Rouge, Louisiana, in 1939. After graduation, he was employed by the Glenn L. Martin Company of Baltimore, Maryland, and later that same year joined the staff of the NACA Langley Memorial Aeronautical Laboratory, where he worked as an engineer in the Flight Division. During the period from September 1946 to July 1954 Williams supervised the activities of several research projects. These included the first successful rocket-powered flight of the XS-1 made by Bell pilot Chalmers Goodlin on December 9, 1946; the record breaking flight of A.F. Captain Chuck Yeager on October 14, 1947, that exceeded the speed of sound; and the first flight of the jet

Comparison of NACA 6-series and 4-digit airfoils for Darrieus wind turbines

NASA Astrophysics Data System (ADS)

Migliore, P. G.

1983-08-01

The aerodynamic efficiency of Darrieus wind turbines as effected by blade airfoil geometry was investigated. Analysis was limited to curved-bladed machines having rotor solidities of 7-21 percent and operating at a Reynolds number of 3 x 10 to the 6th. Ten different airfoils, having thickness-to-chord ratios of 12, 15, and 18 percent, were studied. Performance estimates were made using a blade element/momentum theory approach. Results indicated that NACA 6-series airfoils yield peak power coefficients as great as NACA 4-digit airfoils and have broader and flatter power coefficient-tip speed ratio curves. Sample calculations for an NACA 63(2)-015 airfoil showed an annual energy output increase of 17-27 percent, depending on rotor solidity, compared to an NACA 0015 airfoil.

NACA documents database project

NASA Technical Reports Server (NTRS)

Smith, Ruth S.

1991-01-01

The plan to get all the National Advisory Committee on Aeronautics (NACA) collection online, with quality records, led to the NACA Documents Data base Project. The project has a two fold purpose: (1) to develop the definitive bibliography of NACA produced and/or held documents; and (2) to make that bibliography and the associated documents available to the aerospace community. This study supports the first objective by providing an analysis of the NACA collection and its bibliographic records, and supports the second objective by defining the NACA archive and recommending methodologies for meeting the project objectives.

Flight Studies of Problems Pertinent to High-Speed Operation of Jet Transports

NASA Technical Reports Server (NTRS)

Butchart, Stanley P.; Fischel, Jack; Tremant, Robert A.; Robinson, Glenn H.

1959-01-01

A flight investigation was made to assess the potential operational problems of jet transports in the transonic cruise range. In this study a large multiengine jet airplane having geometric characteristics fairly representative of the jet transport was used; however, in order to ensure general applicability of the results, the aerodynamic characteristics of the test airplane were varied to simulate a variety of jet- transport airplanes. Some of the specific areas investigated include: (1) an overall evaluation of longitudinal stability and control characteristics at transonic speeds, with an assessment of pitch-up characteristics, (2) the effect of buffeting on airplane operational speeds and maneuvering, (3) the desirable lateral-directional damping characteristics, (4) the desirable lateral-control characteristics, (5) an assessment of over-speed and speed-spread requirements, including the upset maneuver, and (6) an assessment of techniques and airplane characteristics for rapid descent and slow-down. The results presented include pilots' evaluation of the various problem areas and specific recommendations for possible improvement of jet-transport operations in the cruising speed range.

E-2889

NASA Image and Video Library

1953-08-04

A 1953 photo of some of the research aircraft at the NACA High-Speed Flight Research Station (now known as the the Dryden Flight Research Center). The photo shows the X-3 (center) and, clockwise from left: X-1A (Air Force serial number 48-1384), the third D-558-1 (NACA tail number 142), XF-92A, X-5, D-558-2, and X-4.

Behavioural system identification of visual flight speed control in Drosophila melanogaster

PubMed Central

Rohrseitz, Nicola; Fry, Steven N.

2011-01-01

Behavioural control in many animals involves complex mechanisms with intricate sensory-motor feedback loops. Modelling allows functional aspects to be captured without relying on a description of the underlying complex, and often unknown, mechanisms. A wide range of engineering techniques are available for modelling, but their ability to describe time-continuous processes is rarely exploited to describe sensory-motor control mechanisms in biological systems. We performed a system identification of visual flight speed control in the fruitfly Drosophila, based on an extensive dataset of open-loop responses previously measured under free flight conditions. We identified a second-order under-damped control model with just six free parameters that well describes both the transient and steady-state characteristics of the open-loop data. We then used the identified control model to predict flight speed responses after a visual perturbation under closed-loop conditions and validated the model with behavioural measurements performed in free-flying flies under the same closed-loop conditions. Our system identification of the fruitfly's flight speed response uncovers the high-level control strategy of a fundamental flight control reflex without depending on assumptions about the underlying physiological mechanisms. The results are relevant for future investigations of the underlying neuromotor processing mechanisms, as well as for the design of biomimetic robots, such as micro-air vehicles. PMID:20525744

Behavioural system identification of visual flight speed control in Drosophila melanogaster.

PubMed

Rohrseitz, Nicola; Fry, Steven N

2011-02-06

Behavioural control in many animals involves complex mechanisms with intricate sensory-motor feedback loops. Modelling allows functional aspects to be captured without relying on a description of the underlying complex, and often unknown, mechanisms. A wide range of engineering techniques are available for modelling, but their ability to describe time-continuous processes is rarely exploited to describe sensory-motor control mechanisms in biological systems. We performed a system identification of visual flight speed control in the fruitfly Drosophila, based on an extensive dataset of open-loop responses previously measured under free flight conditions. We identified a second-order under-damped control model with just six free parameters that well describes both the transient and steady-state characteristics of the open-loop data. We then used the identified control model to predict flight speed responses after a visual perturbation under closed-loop conditions and validated the model with behavioural measurements performed in free-flying flies under the same closed-loop conditions. Our system identification of the fruitfly's flight speed response uncovers the high-level control strategy of a fundamental flight control reflex without depending on assumptions about the underlying physiological mechanisms. The results are relevant for future investigations of the underlying neuromotor processing mechanisms, as well as for the design of biomimetic robots, such as micro-air vehicles.

An Investigation of the Drag of Windshields in the 8-foot High-Speed Wind Tunnel

NASA Technical Reports Server (NTRS)

Robinson, Russell G; Delano, James B

1942-01-01

Report presents the results of tests made to determine the drag of closed-cockpit and transport-type windshields. The tests were made at speeds corresponding to a Mach number range of approximately 0.25 to 0.58 in the NACA 8-foot high-speed wind tunnel. This speed range corresponds to a test Reynolds number range of 2,510,000 to 4,830,000 based on the mean aerodynamic chord of the full-span model (17.29 in.). The shapes of the windshield proper, the hood, and the tail fairing were systematically varied to include common types and refined design.

Analysis of Method TO-14 target analytes using a cryofocusing high-speed gas chromatograph interfaced to a high-speed time-of-flight mass spectrometer

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

Berkley, R.E.; Gardner, B.D.; Holland, J.F.

1997-12-31

A high-speed gas chromatograph coupled with a high-speed time-of-flight mass spectrometer was used to gain a six-fold increase in overall rate of analytical throughput for analysis of EPA Method TO-14 target compounds. Duration of chromatograms was 180 seconds. One hundred mass spectra per second, ranging from 35 to 270 mass units, were collected. Single ion chromatograms were searched at appropriate retention times for chromatographic peaks, which were integrated. Thirty-eight of the forty-one TO-14 target compounds were calibrated using standards at five concentrations from 2.5 to 40 ppb. Four grab samples of ambient air were collected at four different locations atmore » an automobile repair facility, and two grab samples were collected less than one minute apart at a site near a chemical plant, just before and just after passage of three large diesel trucks. All samples were analyzed on the same day they were collected. Most of the duplicate analyses were in close agreement. Ability of the high-speed TOF/GC/MS system to perform analyses of TO-14 target compounds rapidly and precisely was demonstrated. This paper has been reviewed according to US Environmental Protection Agency peer and administrative review policies and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.« less

Fairchild C-82 Packet Destroyed in NACA Crash Fire Tests

NASA Image and Video Library

1952-09-21

A Fairchild C-82 Packet is purposely destroyed by researchers at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. In response to an escalating number of transport aircraft crashes in the mid-1940s, the NACA researchers undertook a decade-long investigation into a number of issues surrounding low-altitude aircraft crashes. The tests were conducted at the Ravenna Arsenal, approximately 60 miles south of the Lewis laboratory in Cleveland, Ohio. The aircraft were excess military transports from World War II. The aircraft was guided down the runway at speeds of 80 to 105 miles per hour. It came into contact with poles which tore open the 1500-gallon fuel tanks in the wings before reaching the barriers at the end of the runway. Fuel poured from the tanks and supply lines, resulting in the spread of both liquid fuel and a large cloud of spray. Solomon Weiss developed a method of dying the fuel red to improve its visibility during the crashes. This red fuel cloud trailed slightly behind the skidding aircraft, then rushed forward when the aircraft stopped. The nine-crash initial phase of testing used Lockheed C-56 Lodestar and C-82 transport aircraft to identify potential ignition sources and analyze the spread of flammable materials. The researchers were able to identify different classes of ignition sources, fuel disbursement patterns, the time when a particular ignition source might appear, rate of the fire spread, cabin survival times, and deceleration rates.

Kinematics of flap-bounding flight in the zebra finch over a wide range of speeds

PubMed

Tobalske; Peacock; Dial

1999-07-01

It has been proposed elsewhere that flap-bounding, an intermittent flight style consisting of flapping phases interspersed with flexed-wing bounds, should offer no savings in average mechanical power relative to continuous flapping unless a bird flies 1.2 times faster than its maximum range speed (Vmr). Why do some species use intermittent bounds at speeds slower than 1.2Vmr? The 'fixed-gear hypothesis' suggests that flap-bounding is used to vary mean power output in small birds that are otherwise constrained by muscle physiology and wing anatomy to use a fixed muscle shortening velocity and pattern of wing motion at all flight speeds; the 'body-lift hypothesis' suggests that some weight support during bounds could make flap-bounding flight aerodynamically advantageous in comparison with continuous flapping over most forward flight speeds. To test these predictions, we studied high-speed film recordings (300 Hz) of wing and body motion in zebra finches (Taenopygia guttata, mean mass 13.2 g, N=4) taken as the birds flew in a variable-speed wind tunnel (0-14 m s-1). The zebra finches used flap-bounding flight at all speeds, so their flight style was unique compared with that of birds that facultatively shift from continuous flapping or flap-gliding at slow speeds to flap-bounding at fast speeds. There was a significant effect of flight speed on all measured aspects of wing motion except percentage of the wingbeat spent in downstroke. Changes in angular velocity of the wing indicated that contractile velocity in the pectoralis muscle changed with flight speed, which is not consistent with the fixed-gear hypothesis. Although variation in stroke-plane angle relative to the body, pronation angle of the wing and wing span at mid-upstroke showed that the zebra finch changed within-wingbeat geometries according to speed, a vortex-ring gait with a feathered upstroke appeared to be the only gait used during flapping. In contrast, two small species that use continuous flapping

Correlation of the Drag Characteristics of a Typical Pursuit Airplane Obtained from High-Speed Wind-Tunnel and Flight Tests

NASA Technical Reports Server (NTRS)

Nissen, James M; Gadebero, Burnett L; Hamilton, William T

1948-01-01

In order to obtain a correlation of drag data from wind-tunnel and flight tests at high Mach numbers, a typical pursuit airplane, with the propeller removed, was tested in flight at Mach numbers up to 0.755, and the results were compared with wind-tunnel tests of a 1/3-scale model of the airplane. The tests results show that the drag characteristics of the test airplane can be predicted with satisfactory accuracy from tests in the Ames 16-foot high-speed wind tunnel of the Ames Aeronautical Laboratory at both high and low Mach numbers. It is considered that this result is not unique with the airplane.

D-558-2 being mounted to P2B-1S launch aircraft

NASA Technical Reports Server (NTRS)

1953-01-01

This 1953 NACA High-Speed Flight Research Station photograph shows the Douglas D-558-2 #2 Skyrocket (NACA 144), prior to flight, being towed under the P2B-1S (Navy designation for the Air Force B-29) launch vehicle (NACA 137) for attachment. In this view the tail of the Skyrocket is almost aligned with the opening cut to fit in the bottom of the P2B-1S. The photograph also shows the large hydraulic jacks used to elevate the P2B-1S launch vehicle. The Douglas D-558-2 'Skyrockets' were among the early transonic research airplanes like the X-1, X-4, X-5, and X-92A. Three of the single-seat, swept-wing aircraft flew from 1948 to 1956 in a joint program involving the National Advisory Committee for Aeronautics (NACA), with its flight research done at the NACA's Muroc Flight Test Unit in Calif., redesignated in 1949 the High-Speed Flight Research Station (HSFRS). Also partners in the flight research were the Navy-Marine Corps and the Douglas Aircraft Co. The HSFRS became the High-Speed Flight Station in 1954 and is now known as the NASA Dryden Flight Research Center. The Skyrocket made aviation history when it became the first airplane to fly twice the speed of sound. The 2 in the aircraft's designation referred to the fact that the Skyrocket was the phase-two version of what had originally been conceived as a three-phase program, with the phase-one aircraft having straight wings. The third phase, which never came to fruition, would have involved constructing a mock-up of a combat-type aircraft embodying the results from the testing of the phase one and two aircraft. Douglas pilot John F. Martin made the first flight at Muroc Army Airfield (later renamed Edwards Air Force Base) in Calif. on February 4, 1948. The goals of the program were to investigate the characteristics of swept-wing aircraft at transonic and supersonic speeds with particular attention to pitch-up (uncommanded rotation of the nose of the airplane upwards)--a problem prevalent in high-speed service

NACA Conference on Helicopters

DTIC Science & Technology

1954-05-01

Louis S., Jr.: Summary of Airfoil Data. NACA Rep. 824, 1945. (Supersedes NACA WR L-560.) 2. Loftin, Laurence K., Jr., and Smith , Hamilton, A...F., and Smith , Hamilton A.: Aerodynamic Character- istics of the NACA 8-H-12 Airfoil Section at Six Reynold Numbers From 1.8 x 1u6 to 11.0 X 106...NACA TN 1998, 1949. 4. Smith , Hamilton A., and Schaefer, Raymond F.: Aerodynamic Character- 0 istics at Reynolds Numbers of 3.0 X 106 and 6.0 x 106 of

High-Speed Isolation Board for Flight Hardware Testing

NASA Technical Reports Server (NTRS)

Yamamoto, Clifford K.; Goodpasture, Richard L.

2011-01-01

There is a need to provide a portable and cost-effective galvanic isolation between ground support equipment and flight hardware such that any unforeseen voltage differential between ground and power supplies is eliminated. An interface board was designed for use between the ground support equipment and the flight hardware that electrically isolates all input and output signals and faithfully reproduces them on each side of the interface. It utilizes highly integrated multi-channel isolating devices to minimize size and reduce assembly time. This single-board solution provides appropriate connector hardware and breakout of required flight signals to individual connectors as needed for various ground support equipment. The board utilizes multi-channel integrated circuits that contain transformer coupling, thereby allowing input and output signals to be isolated from one another while still providing high-fidelity reproduction of the signal up to 90 MHz. The board also takes in a single-voltage power supply input from the ground support equipment and in turn provides a transformer-derived isolated voltage supply to power the portion of the circuitry that is electrically connected to the flight hardware. Prior designs used expensive opto-isolated couplers that were required for each signal to isolate and were time-consuming to assemble. In addition, these earlier designs were bulky and required a 2U rack-mount enclosure. The new design is smaller than a piece of 8.5 11-in. (.22 28-mm) paper and can be easily hand-carried where needed. The flight hardware in question is based on a lineage of existing software-defined radios (SDRs) that utilize a common interface connector with many similar input-output signals present. There are currently four to five variations of this SDR, and more upcoming versions are planned based on the more recent design.

D-558-2 being mounted to P2B-1S launch aircraft

NASA Technical Reports Server (NTRS)

1953-01-01

This 1953 NACA High-Speed Flight Research Station photograph shows the Douglas D-558-2 #2 Skyrocket (NACA 144), prior to flight, being towed under the P2B-1S launch vehicle (NACA 137) for attachment. The photograph also shows the large hydraulic jacks used to elevate the P2B-1S launch vehicle. Once the D-558-2 was in position, the P2B-1S would be lowered and the attachment made. The Douglas D-558-2 'Skyrockets' were among the early transonic research airplanes like the X-1, X-4, X-5, and X-92A. Three of the single-seat, swept-wing aircraft flew from 1948 to 1956 in a joint program involving the National Advisory Committee for Aeronautics (NACA), with its flight research done at the NACA's Muroc Flight Test Unit in Calif., redesignated in 1949 the High-Speed Flight Research Station (HSFRS); the Navy-Marine Corps; and the Douglas Aircraft Co. The HSFRS became the High-Speed Flight Station in 1954 and is now known as the NASA Dryden Flight Research Center. The Skyrocket made aviation history when it became the first airplane to fly twice the speed of sound. The 2 in the aircraft's designation referred to the fact that the Skyrocket was the phase-two version of what had originally been conceived as a three-phase program, with the phase-one aircraft having straight wings. The third phase, which never came to fruition, would have involved constructing a mock-up of a combat-type aircraft embodying the results from the testing of the phase one and two aircraft. Douglas pilot John F. Martin made the first flight at Muroc Army Airfield (later renamed Edwards Air Force Base) in Calif. on February 4, 1948. The goals of the program were to investigate the characteristics of swept-wing aircraft at transonic and supersonic speeds with particular attention to pitch-up (uncommanded rotation of the nose of the airplane upwards)--a problem prevalent in high-speed service aircraft of that era, particularly at low speeds during take-off and landing and in tight turns. The three

A Flight Evaluation of the Factors which Influence the Selection of Landing Approach Speeds

NASA Technical Reports Server (NTRS)

Drinkwater, Fred J., III; Cooper, George E.

1958-01-01

The factors which influence the selection of landing approach speeds are discussed from the pilot's point of view. Concepts were developed and data were obtained during a landing approach flight investigation of a large number of jet airplane configurations which included straight-wing, swept-wing, and delta-wing airplanes as well as several applications of boundary-layer control. Since the fundamental limitation to further reductions in approach speed on most configurations appeared to be associated with the reduction in the pilot's ability to control flight path angle and airspeed, this problem forms the basis of the report. A simplified equation is presented showing the basic parameters which govern the flight path angle and airspeed changes, and pilot control techniques are discussed in relation to this equation. Attention is given to several independent aerodynamic characteristics which do not affect the flight path angle or airspeed directly but which determine to a large extent the effort and attention required of the pilot in controlling these factors during the approach. These include stall characteristics, stability about all axes, and changes in trim due to thrust adjustments. The report considers the relationship between piloting technique and all of the factors previously mentioned. A piloting technique which was found to be highly desirable for control of high-performance airplanes is described and the pilot's attitudes toward low-speed flight which bear heavily on the selection of landing approach speeds under operational conditions are discussed.

Camera Installation on a Beach AT-11

NASA Image and Video Library

1950-02-21

Researchers at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory conducted an extensive investigation into the composition of clouds and their effect on aircraft icing. The researcher in this photograph is installing cameras on a Beach AT-11 Kansan in order to photograph water droplets during flights through clouds. The twin engine AT-11 was the primary training aircraft for World War II bomber crews. The NACA acquired this aircraft in January 1946, shortly after the end of the war. The NACA Lewis’ icing research during the war focused on the resolution of icing problems for specific military aircraft. In 1947 the laboratory broadened its program and began systematically measuring and categorizing clouds and water droplets. The three main thrusts of the Lewis icing flight research were the development of better instrumentation, the accumulation of data on ice buildup during flight, and the measurement of droplet sizes in clouds. The NACA researchers developed several types of measurement devices for the icing flights, including modified cameras. The National Research Council of Canada experimented with high-speed cameras with a large magnification lens to photograph the droplets suspended in the air. In 1951 NACA Lewis developed and flight tested their own camera with a magnification of 32. The camera, mounted to an external strut, could be used every five seconds as the aircraft reached speeds up to 150 miles per hour. The initial flight tests through cumulus clouds demonstrated that droplet size distribution could be studied.

Historical perspectives on thermostructural research at the NACA Langley Aeronautical Laboratory from 1948 to 1958

NASA Technical Reports Server (NTRS)

Heldenfels, R. R.

1982-01-01

Research on structural problems associated with aerodynamic heating, conducted by the National Advisory Committee for Aeronautics (NACA) during its last decade are described. The text of a special presentation given at the NASA Symposium on Computational Aspects of Heat Transfer in Structure is presented. Some early thermostructural research activities using charts is also discussed. The prinicipal message of the paper is that although vehicle oriented research programs speed development of new technology for specific missions, too much effort may be expended on developing technology which is never used because a vehicle is never built. A healthy research program must provide freedom to explore new ideas that have no obvious applications at the time to generate the technology that makes important, unanticipated flight or vehicle opportunities possible.

Farfield inflight measurements of high-speed turboprop noise

NASA Technical Reports Server (NTRS)

Balombin, J. R.; Loeffler, I. J.

1983-01-01

A flight program was carried out to determine the variation of noise level with distance from a model high-speed propeller. Noise measurements were obtained at different distances from a SR-3 propeller mounted on a JetStar aircraft, with the test instrumentation mounted on a Learjet flown in formation. The propeller was operated at 0.8 m flight Mach number, 1.12 helical tip Mach number and at 0.7 flight Mach number, 1.0 helical tip Mach number. The instantaneous pressure from individual blades was observed to rise faster at the 0.8 flight speed, than at the 0.7 M flight speed. The measured levels appeared to decrease in good agreement with a 6 dB/doubling of distance decay, over the measurement range of approximately 16 m to 100 m distance. Further extrapolation, to the distances represented by a community, would suggest that the propagated levels during cruise would not cause a serious community annoyance.

Farfield inflight measurement of high-speed turboprop noise

NASA Technical Reports Server (NTRS)

Balombin, J. R.; Loeffler, I. J.

1982-01-01

A flight program was carried out to determine the variation of noise level with distance from a model high speed propeller. Noise measurements were obtained at different distances from a SR-3 propeller mounted on a JetStar aircraft, with the test instrumentation mounted on a Lear jet flown in formation. The propeller was operated at 0.8 flight Mach number, 1.12 helical tip Mach number and at 0.7 flight Mach number, 1.0 helical tip Mach number. The instantaneous pressure from individual blades was observed to rise faster at the 0.8 M flight speed, than at the 0.7 M flight speed. The measured levels appeared to decrease in good agreement with a 6 dB/doubling of distance decay, over the measurement range of approximately 16 m to 100 m distance. Further extrapolation, to the distances represented by a community, would suggest that the propagated levels during cruise would not cause a serious community annoyance.

NACA Conference on Turbojet-Engine Thrust Augmentation Research: A Compilation of the Papers Presented by NACA Staff Members

NASA Technical Reports Server (NTRS)

1948-01-01

The conference on Turbojet-Engine Thrust-Augmentation Research was organized by the NACA to present in summarized form the results of the latest experimental and analytical investigations conducted at the Lewis Flight Propulsion Laboratory on methods of augmenting the thrust of turbojet engines. The technical discussions are reproduced herewith in the same form in which they were presented. The original presentation in this record are considered as complementary to, rather than substitutes for, the committee's system of complete and formal reports.

Surface-pressure Distributions on a Systematic Group of NACA 1-series Cowlings with and Without Spinners

NASA Technical Reports Server (NTRS)

Boswinkle, Robert W JR; Keith, Arvid L JR

1948-01-01

A method for calculating the flow fields of axially symmetric bodies from their pressure distributions is reported in NACA RM No. L8I17. In order to facilitate application of this method to the important case of the cowling-spinner combination, for use in the design of propellers, the present paper presents static-pressure distributions on the tops of 79 high-critical-speed NACA 1-series cowling-spinner combinations over wide ranges of inlet-velocity ratio at angles of attack of 0 degrees, 2 degrees, 4 degrees, and 6 degrees. Static-pressure distributions around the nose sections of several cowlings are given in greater detail to aid in estimating the pressures near the stagnation points and to show the effect of changes in the internal lip shape. The effects of the operation of a typical propeller on the surface pressures on the cowling are shown for one configuration. The pressure distributions over the nine NACA 1-series nose inlets used as the basic components of these combinations are also presented ro supplement the existing open-nose-cowling data of NACA ACR No. L5F30a which are applicable to the case of the rotating cowling.

Functional integration of vertical flight path and speed control using energy principles

NASA Technical Reports Server (NTRS)

Lambregts, A. A.

1984-01-01

A generalized automatic flight control system was developed which integrates all longitudinal flight path and speed control functions previously provided by a pitch autopilot and autothrottle. In this design, a net thrust command is computed based on total energy demand arising from both flight path and speed targets. The elevator command is computed based on the energy distribution error between flight path and speed. The engine control is configured to produce the commanded net thrust. The design incorporates control strategies and hierarchy to deal systematically and effectively with all aircraft operational requirements, control nonlinearities, and performance limits. Consistent decoupled maneuver control is achieved for all modes and flight conditions without outer loop gain schedules, control law submodes, or control function duplication.

The effects of NACA 0012 airfoil modification on aerodynamic performance improvement and obtaining high lift coefficient and post-stall airfoil

NASA Astrophysics Data System (ADS)

Sogukpinar, Haci

2018-02-01

In this study, aerodynamic performances of NACA 0012 airfoils with distinct modification are numerically investigated to obtain high lift coefficient and post-stall airfoils. NACA 0012 airfoil is divided into two part thought chord line then suction sides kept fixed and by changing the thickness of the pressure side new types of airfoil are created. Numerical experiments are then conducted by varying thickness of NACA 0012 from lower surface and different relative thicknesses asymmetrical airfoils are modified and NACA 0012-10, 0012-08, 0012-07, 0012-06, 0012-04, 0012-03, 0012-02, 0012-01 are created and simulated by using COMSOL software.

Enhanced thrust and speed revealed in the forward flight of a butterfly with transient body translation.

PubMed

Fei, Yueh-Han John; Yang, Jing-Tang

2015-09-01

A butterfly with broad wings, flapping at a small frequency, flies an erratic trajectory at an inconstant speed. A large variation of speed within a cycle is observed in the forward flight of a butterfly. A self-propulsion model to simulate a butterfly is thus created to investigate the transient translation of the body; the results, which are in accordance with experimental data, show that the shape of the variation of the flight speed is similar to a sinusoidal wave with a maximum (J=0.89) at the beginning of the downstroke, and a decrease to a minimum (J=0.17) during a transition from downstroke to upstroke; the difference between the extrema of the flight speed is enormous in a flapping cycle. At a high speed, a clapping motion of the butterfly wings decreases the generation of drag. At a small speed, a butterfly is able to capture the induced wakes generated in a downstroke, and effectively generates a thrust at the beginning of an upstroke. The wing motion of a butterfly skillfully interacts with its speed so as to enable an increased speed with the same motion. Considering a butterfly to fly in a constant inflow leads to either an underestimate of its speed or an overestimate of its generated lift, which yields an inaccurate interpretation of the insect's flight. Our results reveal the effect of transient translation on a butterfly in forward flight, which is especially important for an insect with a small flapping frequency.

Enhanced thrust and speed revealed in the forward flight of a butterfly with transient body translation

NASA Astrophysics Data System (ADS)

Fei, Yueh-Han John; Yang, Jing-Tang

2015-09-01

A butterfly with broad wings, flapping at a small frequency, flies an erratic trajectory at an inconstant speed. A large variation of speed within a cycle is observed in the forward flight of a butterfly. A self-propulsion model to simulate a butterfly is thus created to investigate the transient translation of the body; the results, which are in accordance with experimental data, show that the shape of the variation of the flight speed is similar to a sinusoidal wave with a maximum (J =0.89 ) at the beginning of the downstroke, and a decrease to a minimum (J =0.17 ) during a transition from downstroke to upstroke; the difference between the extrema of the flight speed is enormous in a flapping cycle. At a high speed, a clapping motion of the butterfly wings decreases the generation of drag. At a small speed, a butterfly is able to capture the induced wakes generated in a downstroke, and effectively generates a thrust at the beginning of an upstroke. The wing motion of a butterfly skillfully interacts with its speed so as to enable an increased speed with the same motion. Considering a butterfly to fly in a constant inflow leads to either an underestimate of its speed or an overestimate of its generated lift, which yields an inaccurate interpretation of the insect's flight. Our results reveal the effect of transient translation on a butterfly in forward flight, which is especially important for an insect with a small flapping frequency.

Science and Technology of Low Speed and Motorless Flight, Part 1

NASA Technical Reports Server (NTRS)

Hanson, P. W. (Compiler)

1979-01-01

The proceedings of the Third International Symposium on the Science and Technology of Low Speed and Motorless Flight are reported. Twenty-eight papers were presented in the areas of low speed aerodynamics, new materials applications and structural concepts, advanced flight instrumentation, sailplane optimal flight techniques, and self launching and ultralight glider technology. These papers are included in the document along with another paper, which was not presented, on proposed definitions for various categories of sailplanes and gliders.

Effect of Various Modifications on Drag and Longitudinal Stability and Control Characteristics at Transonic Speeds of a Model of the XF7U-1 Tailless Airplane: NACA Wing-FLow Method, TED No. NACA DE 307

NASA Technical Reports Server (NTRS)

Sawyer, Richard H.; Trant, James P., Jr.

1950-01-01

An investigation was made by the NACA wing-flow method to determine the drag, pitching-moment, lift, and angle-of-attack characteristics at transonic speeds of various configurations of a semispan model of an early configuration of the XF7U-1 tailless airplane. The results of the tests indicated that for the basic configuration with undeflected ailavator, the zero-lift drag rise occurred at a Mach number of about 0.85 and that about a five-fold increase in drag occurred through the transonic speed range. The results of the tests also indicated that the drag increment produced by -8.0 degrees deflection of the ailavator increased with increase in normal-force coefficient and was smaller at speeds above than at speeds below the drag rise. The drag increment produced by 35 degree deflection of the speed brakes varied from 0.040 to 0.074 depending on the normal-force coefficient and Mach number. These values correspond to drag coefficients of about 0.40 and 0.75 based on speed-brake frontal area. Removal of the fin produced a small positive drag increment at a given normal-force coefficient at speeds during the drag rise. A large forward shift of the neutral-point location occurred at Mach numbers above about 0.90 upon removal of the fin, and also a considerable forward shift throughout the Mach number range occurred upon deflection of the speed brakes. Ailavator ineffectiveness or reversal at low deflections, similar to that determined in previous tests of the basic configuration of the model in the Mach number range from about 0.93 to 1.0, was found for the fin-off configuration and for the model equipped with skewed (more highly sweptback) hinge-line ailavators. With the speed brakes deflected, little or no loss in the incremental pitching moment produced by deflection of the ailavator from O degrees to -8.00 degrees occurred in the Mach number range from 0.85 to 1.0 in contrast to a considerable loss found in previous tests with the speed brakes off.

Flight metabolism in relation to speed in Chiroptera: testing the U-shape paradigm in the short-tailed fruit bat Carollia perspicillata.

PubMed

von Busse, Rhea; Swartz, Sharon M; Voigt, Christian C

2013-06-01

Aerodynamic theory predicts that flight for fixed-wing aircraft requires more energy at low and high speeds compared with intermediate speeds, and this theory has often been extended to predict speed-dependent metabolic rates and optimal flight speeds for flying animals. However, the theoretical U-shaped flight power curve has not been robustly tested for Chiroptera, the only mammals capable of flapping flight. We examined the metabolic rate of seven Seba's short-tailed fruit bats (Carollia perspicillata) during unrestrained flight in a wind tunnel at air speeds from 1 to 7 m s(-1). Following intra-peritoneal administration of (13)C-labeled Na-bicarbonate, we measured the enrichment in (13)C of exhaled breath before and after flight. We converted fractional turnover of (13)C into metabolic rate and power, based on the assumption that bats oxidized glycogen during short flights. Power requirements of flight varied with air speed in a U-shaped manner in five out of seven individuals, whereas energy turnover was not related to air speed in two individuals. Power requirements of flight were close to values predicted by Pennycuick's aerodynamic model for minimum power speed, but differed for maximum range speed. The results of our experiment support the theoretical expectation of a U-shaped power curve for flight metabolism in a bat.

Validations of Coupled CSD/CFD and Particle Vortex Transport Method for Rotorcraft Applications: Hover, Transition, and High Speed Flights

NASA Technical Reports Server (NTRS)

Anusonti-Inthra, Phuriwat

2010-01-01

This paper presents validations of a novel rotorcraft analysis that coupled Computational Fluid Dynamics (CFD), Computational Structural Dynamics (CSD), and Particle Vortex Transport Method (PVTM) methodologies. The CSD with associated vehicle trim analysis is used to calculate blade deformations and trim parameters. The near body CFD analysis is employed to provide detailed near body flow field information which is used to obtain high-fidelity blade aerodynamic loadings. The far field wake dominated region is simulated using the PVTM analysis which provides accurate prediction of the evolution of the rotor wake released from the near body CFD domains. A loose coupling methodology between the CSD and CFD/PVTM modules are used with appropriate information exchange amongst the CSD/CFD/PVTM modules. The coupled CSD/CFD/PVTM methodology is used to simulate various rotorcraft flight conditions (i.e. hover, transition, and high speed flights), and the results are compared with several sets of experimental data. For the hover condition, the results are compared with hover data for the HART II rotor tested at DLR Institute of Flight Systems, Germany. For the forward flight conditions, the results are validated with the UH-60A flight test data.

Aircraft Fleet on the Tarmac at the Lewis Flight Propulsion Laboratory

NASA Image and Video Library

1946-04-21

This fleet of military aircraft was used in the 1940s for research at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory in Cleveland, Ohio. The NACA Lewis flight research program was established in March 1943 to augment the lab’s wartime research efforts. NACA Lewis possessed a host of wind tunnels, test stands, and other ground facilities designed to replicate flight conditions, but actual flight tests remained an integral research tool. The military loaned NACA Lewis 15 different aircraft during World War II and six others in the six months following the end of hostilities. During the war these aircraft supported three main efforts: the improved performance of reciprocating engines, better fuel additives and mixtures, and deicing systems. The wartime researchers used the types of aircraft which the studies were intended to improve. After the war the research aircraft served as test beds to investigate engines or systems that often had little to do with the research aircraft. During the war, NACA Lewis’ three pilots were supported by 16 flight engineers, 36 mechanics, and 10 instrumentation specialists. The visible aircraft, from left to right, are a Boeing B-29 Superfortress, a Martin B-26A Marauder, two Consolidated B-24 Liberators, a Cessna UC-78 Bobcat, and a Northrop P-61 Black Widow. Partially obscured are a North American P-51 Mustang, a Bell P-63 King Cobra, a North American AT-6 Texan, and a Lockheed RA-29 Hudson.

High speed commercial transport fuels considerations and research needs

NASA Technical Reports Server (NTRS)

Lee, C. M.; Niedzwiecki, R. W.

1989-01-01

NASA is currently evaluating the potential of incorporating High Speed Civil Transport (HSCT) aircraft in the commercial fleet in the beginning of the 21st century. NASA sponsored HSCT enabling studies currently underway with airframers and engine manufacturers, are addressing a broad range of technical, environmental, economic, and related issues. Supersonic cruise speeds for these aircraft were originally focused in the Mach 2 to 5 range. At these flight speeds, both jet fuels and liquid methane were considered potential fuel candidates. For the year 2000 to 2010, cruise Mach numbers of 2 to 3+ are projected for aircraft fuel with thermally stable liquid jet fuels. For 2015 and beyond, liquid methane fueled aircraft cruising at Mach numbers of 4+ may be viable candidates. Operation at supersonic speeds will be much more severe than those encountered at subsonic flight. One of the most critical problems is the potential deterioration of the fuel due to the high temperature environment. HSCT fuels will not only be required to provide the energy necessary for flight, but will also be subject to aerodynamic heating and, will be required to serve as the primary heat sink for cooling the engine and airframe. To define fuel problems for high speed flight, a fuels workshop was conducted at NASA Lewis Research Center. The purpose of the workshop was to gather experts on aviation fuels, airframe fuel systems, airport infrastructure, and combustion systems to discuss high speed fuel alternatives, fuel supply scenarios, increased thermal stability approaches and measurements, safety considerations, and to provide directional guidance for future R and D efforts. Subsequent follow-up studies defined airport infrastructure impacts of high speed fuel candidates. The results of these activities are summarized. In addition, an initial case study using modified in-house refinery simulation model Gordian code (1) is briefly discussed. This code can be used to simulate different

NACA/NASA test pilot Stanley P. Butchart

NASA Technical Reports Server (NTRS)

1954-01-01

Stanley P. Butchart joined the National Advisory Committee for Aeronautics' High-Speed Flight Research Station on May 10, 1951. Stan was the fourth research pilot hired at the Station affording him the opportunity to fly the early research aircraft. Stan began a flying career while attending Junior College. He received primary and secondary civilian pilot training, enlisting in the U.S. Navy in July 1942. Stan took his Navy air training at Corpus Christi, Texas. Upon completion of training he was assigned to a torpedo-bomber Air Group, VT-51, flying Grumman-General Motors TBM Avenger, a torpedo-bomber, from the carrier San Jacinto in the South Pacific. When World War II ended, Stan was released from active duty as a Navy Lieutenant, with a Distinguished Flying Cross and a Presidential Unit Citation among his service medals. Butchart elected to stay in the Naval Reserve group and flew for an additional 5 years while he attended the University of Washington. By 1950, Stan had earned bachelor degrees in aeronautical engineering and mechanical engineering. After graduation he went to work for Boeing Aircraft as a junior design engineer and was assigned to the B-47 body group. In May 1951, he arrived at the NACA facility to start a career as a research pilot. Stan flew the Douglas D-558-I #3 (12 flights, first on October 19, 1951), the Douglas D-558-II #3 (2 pilot check-out flights, first on June 26, 1953), Northrop X-4 (4 flights, first on May 27, 1952), Bell X-5 (13 flights, first in early December 1952). Other aircraft flown on research projects were the Boeing KC-135 Stratotanker, Convair CV-990, Boeing B-52-003, Boeing B-747, North American F-100A, Convair F-102, Piper PA-30 Twin Comanche, General Dynamics F-111, Boeing B-720, Convair CV-880, and the Boeing B-47 Stratojet, his favorite. he also flew many other aircraft. Stan did nearly all of the big airplane work at the Center. The biggest work load was flying the Boeing B-29 Stratofortress (Navy designation: P2B

Effects of independent variation of Mach and Reynolds numbers on the low-speed aerodynamic characteristics of the NACA 0012 airfoil section

NASA Technical Reports Server (NTRS)

Ladson, Charles L.

1988-01-01

A comprehensive data base is given for the low speed aerodynamic characteristics of the NACA 0012 airfoil section. The Langley low-turbulence pressure tunnel is the facility used to obtain the data. Included in the report are the effects of Mach number and Reynolds number and transition fixing on the aerodynamic characteristics. Presented are also comparisons of some of the results with previously published data and with theoretical estimates. The Mach number varied from 0.05 to 0.36. The Reynolds number, based on model chord, varied from 3 x 10 to the 6th to 12 x 10 to the 6th power.

Kinematics and wing shape across flight speed in the bat, Leptonycteris yerbabuenae

PubMed Central

Von Busse, Rhea; Hedenström, Anders; Winter, York; Johansson, L. Christoffer

2012-01-01

Summary The morphology and kinematics of a flying animal determines the resulting aerodynamic lift through the regulation of the speed of the air moving across the wing, the wing area and the lift coefficient. We studied the detailed three-dimensional wingbeat kinematics of the bat, Leptonycteris yerbabuenae, flying in a wind tunnel over a range of flight speeds (0–7 m/s), to determine how factors affecting the lift production vary across flight speed and within wingbeats. We found that the wing area, the angle of attack and the camber, which are determinants of the lift production, decreased with increasing speed. The camber is controlled by multiple mechanisms along the span, including the deflection of the leg relative to the body, the bending of the fifth digit, the deflection of the leading edge flap and the upward bending of the wing tip. All these measures vary throughout the wing beat suggesting active or aeroelastic control. The downstroke Strouhal number, Std, is kept relatively constant, suggesting that favorable flow characteristics are maintained during the downstroke, across the range of speeds studied. The Std is kept constant through changes in the stroke plane, from a strongly inclined stroke plane at low speeds to a more vertical stroke plane at high speeds. The mean angular velocity of the wing correlates with the aerodynamic performance and shows a minimum at the speed of maximum lift to drag ratio, suggesting a simple way to determine the optimal speed from kinematics alone. Taken together our results show the high degree of adjustments that the bats employ to fine tune the aerodynamics of the wings and the correlation between kinematics and aerodynamic performance. PMID:23259057

Speed and path control for conflict-free flight in high air traffic demand in terminal airspace

NASA Astrophysics Data System (ADS)

Rezaei, Ali

To accommodate the growing air traffic demand, flights will need to be planned and navigated with a much higher level of precision than today's aircraft flight path. The Next Generation Air Transportation System (NextGen) stands to benefit significantly in safety and efficiency from such movement of aircraft along precisely defined paths. Air Traffic Operations (ATO) relying on such precision--the Precision Air Traffic Operations or PATO--are the foundation of high throughput capacity envisioned for the future airports. In PATO, the preferred method is to manage the air traffic by assigning a speed profile to each aircraft in a given fleet in a given airspace (in practice known as (speed control). In this research, an algorithm has been developed, set in the context of a Hybrid Control System (HCS) model, that determines whether a speed control solution exists for a given fleet of aircraft in a given airspace and if so, computes this solution as a collective speed profile that assures separation if executed without deviation. Uncertainties such as weather are not considered but the algorithm can be modified to include uncertainties. The algorithm first computes all feasible sequences (i.e., all sequences that allow the given fleet of aircraft to reach destinations without violating the FAA's separation requirement) by looking at all pairs of aircraft. Then, the most likely sequence is determined and the speed control solution is constructed by a backward trajectory generation, starting with the aircraft last out and proceeds to the first out. This computation can be done for different sequences in parallel which helps to reduce the computation time. If such a solution does not exist, then the algorithm calculates a minimal path modification (known as path control) that will allow separation-compliance speed control. We will also prove that the algorithm will modify the path without creating a new separation violation. The new path will be generated by adding new

A Preliminary Analysis of the Flying Qualities of the Consolidated Vultee MX-813 Delta-Wing Airplane Configuration at Transonic and Low Supersonic Speeds as Determined from Flights of Rocket-Powered Models

NASA Technical Reports Server (NTRS)

Mitcham, Grady L.

1949-01-01

A preliminary analysis of the flying qualities of the Consolidated Vultee MX-813 delta-wing airplane configuration has been made based on the results obtained from the first two 1/8 scale models flown at the NACA Pilotless Aircraft Research Station, Wallop's Island, VA. The Mach number range covered in the tests was from 0.9 to 1.2. The analysis indicates adequate elevator control for trim in level flight over the speed range investigated. Through the transonic range there is a mild trim change with a slight tucking-under tendency. The elevator control effectiveness in the supersonic range is reduced to about one-half the subsonic value although sufficient control for maneuvering is available as indicated by the fact that 10 deg elevator deflection produced 5g acceleration at Mach number of 1.2 at 40,000 feet.The elevator control forces are high and indicate the power required of the boost system. The damping. of the short-period oscillation is adequate at sea-level but is reduced at 40,000 feet. The directional stability appears adequate for the speed range and angles of attack covered.

Whirl Flutter Stability of Two-Bladed Proprotor/Pylon Systems In High Speed Flight

NASA Technical Reports Server (NTRS)

Singh, Beerinder; Chopra, Inderjit; Pototzky, A. (Technical Monitor)

2002-01-01

The lack of polar symmetry in two-bladed rotors leads to equations of motion with periodic coefficients in axial flight, which is contrary to three or more bladed rotors that result in constant coefficient equations. With periodic coefficients, the analysis becomes involved, as a result very few studies have been directed towards the analysis of two-bladed rotors. In this paper, the aeroelastic stability of two-bladed proprotor/pylon/wing combinations is examined in high speed axial flight. Several parametric studies are carried out to illustrate the special nature of two-bladed proprotors and to better understand the mechanism of whirl-flutter in such rotors. The wing beam bending mode for two-bladed rotors is found to be stable over the range of parameters examined, a behaviour very different from three-bladed rotors. Also, the wing torsion mode exhibits a new type of instability similar to a wing torsional divergence scouring at I/rev frequency. This type of behaviour is not seen in three and more bladed rotors. The interaction between wing chordwise bending and torsion modes is found to be much greater in the case of two-bladed rotors and, over the range of parameters considered, these two modes govern the stability of the system.

X-1 aircraft in flight

NASA Technical Reports Server (NTRS)

1949-01-01

The first of the rocket-powered research aircraft, the X-1 (originally designated the XS-1), was a bullet-shaped airplane that was built by the Bell Aircraft Company for the US Air Force and the National Advisory Committee for Aeronautics (NACA). The mission of the X-1 was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier'. The first of the three X-1s was glide-tested at Pinecastle Field, FL, in early 1946. The first powered flight of the X-1 was made on Dec. 9, 1946, at Muroc Army Air Field (later redesignated Edwards Air Force Base) with Chalmers Goodlin, a Bell test pilot,at the controls. On Oct. 14, 1947, with USAF Captain Charles 'Chuck' Yeager as pilot, the aircraft flew faster than the speed of sound for the first time. Captain Yeager ignited the four-chambered XLR-11 rocket engines after being air-launched from under the bomb bay of a B-29 at 21,000 ft. The 6,000-lb thrust ethyl alcohol/liquid oxygen burning rockets, built by Reaction Motors, Inc., pushed him up to a speed of 700 mph in level flight. Captain Yeager was also the pilot when the X-1 reached its maximum speed of 957 mph. Another USAF pilot. Lt. Col. Frank Everest, Jr., was credited with taking the X-1 to its maximum altitude of 71,902 ft. Eighteen pilots in all flew the X-1s. The number three plane was destroyed in a fire before evermaking any powered flights. A single-place monoplane, the X-1 was 31 ft long, 10 ft high, and had a wingspan of 29 ft. It weighed 4,900 lb and carried 8,200 lb of fuel. It had a flush cockpit with a side entrance and no ejection seat. The following movie runs about 20 seconds, and shows several air-to-air views of X-1 Number 2 and its modified B-50 mothership. It begins with different angles of the X-1 in-flight while mated to the B-50's bomb bay, and ends showing the air-launch. The X-1 drops below the B-50, then accelerates away as the rockets ignite.

Efficient Low-Speed Flight in a Wind Field

NASA Technical Reports Server (NTRS)

Feldman, Michael A.

1996-01-01

A new software tool was needed for flight planning of a high altitude, low speed unmanned aerial vehicle which would be flying in winds close to the actual airspeed of the vehicle. An energy modeled NLP (non-linear programming) formulation was used to obtain results for a variety of missions and wind profiles. The energy constraint derived included terms due to the wind field and the performance index was a weighted combination of the amount of fuel used and the final time. With no emphasis on time and with no winds the vehicle was found to fly at maximum lift to drag velocity, V(sub md). When flying in tail winds the velocity was less than V(sub md), while flying in head winds the velocity was higher than V(sub md). A family of solutions was found with varying times of flight and varying fuel amounts consumed which will aid the operator in choosing a flight plan depending on a desired landing time. At certain parts of the flight, the turning terms in the energy constraint equation were found to be significant. An analysis of a simpler vertical plane cruise optimal control problem was used to explain some of the characteristics of the vertical plane NLP results.

Acoustic measurements on aerofoils moving in a circle at high speed

NASA Technical Reports Server (NTRS)

Wright, S. E.; Crosby, W.; Lee, D. L.

1982-01-01

Features of the test apparatus, research objectives and sample test results at the Stanford University rotor aerodynamics and noise facility are described. A steel frame equipped to receive lead shot for damping vibrations supports the drive shaft for rotor blade elements. Sleeve bearings are employed to assure quietness, and a variable speed ac motor produces the rotations. The test stand can be configured for horizontal or vertical orientation of the drive shaft. The entire assembly is housed in an acoustically sealed room. Rotation conditions for hover and large angles of attack can be studied, together with rotational and blade element noises. Research is possible on broad band, discrete frequency, and high speed noise, with measurements taken 3 m from the center of the rotor. Acoustic signatures from Mach 0.3-0.93 trials with a NACA 0012 airfoil are provided.

Walter C. Williams (1919-1995)

NASA Technical Reports Server (NTRS)

1954-01-01

Walter C. Williams was Chief of the National Advisory Committee for Aeronautics' and the National Aeronautics and Space Administration's flight research organization on Edwards Air Force Base until his appointment as Associate Director of Project Mercury on September 15, 1959. Walt had started his career with NACA at Langley Memorial Aeronautical Laboratory in 1939 as an engineer in the Flight Division. In 1946 he transferred to the Muroc Army Air Field to be in charge of the small group of technicians and engineers who would be doing the flight research on a joint NACA-Army Air Forces program involving the rocket-powered Bell XS-1. See photo DIRECTORS E-49-0170, which addresses the first eight years of Walt's responsibilities with NACA. Williams' achievements as Chief of the NACA/NASA High-Speed Flight Station for the next five years continued to be significant. NACA pilot Joseph A. Walker made the first of 20 NACA research flights in the Douglas X-3 'Flying Stiletto'--on which inertial coupling was first experience--in 1954. The first NACA flight in an Lockheed F-104A aircraft occurred on August 27, 1956. On October 15, 1958, the first of three North American X-15 rocket research aircraft arrived at NASA High Speed Flight Station as preparations moved ahead for the highly successful NASA-Air Force-Navy-North American program that would last 10 years and investigate hypersonic flight. Walt directed a great variety of other flight research programs, including that on the Boeing B-47; investigations using the Century Series fighters, F-100, F-102, F-104, F-105 and F-107; and the ones involving the X-1 #2, which became the X1-E. During Williams' career, he twice received the NASA Distinguished Service Medal and was nominated both to the Meritorious Rank and Distinguished Rank in the Federal Senior Executive Service. In 1963 he was awarded an honorary doctorate of engineering degree by Louisiana State University. He received several awards from the American Institute

European birds adjust their flight initiation distance to road speed limits.

PubMed

Legagneux, Pierre; Ducatez, Simon

2013-10-23

Behavioural responses can help species persist in habitats modified by humans. Roads and traffic greatly affect animals' mortality not only through habitat structure modifications but also through direct mortality owing to collisions. Although species are known to differ in their sensitivity to the risk of collision, whether individuals can change their behaviour in response to this is still unknown. Here, we tested whether common European birds changed their flight initiation distances (FIDs) in response to vehicles according to road speed limit (a known factor affecting killing rates on roads) and vehicle speed. We found that FID increased with speed limit, although vehicle speed had no effect. This suggests that birds adjust their flight distance to speed limit, which may reduce collision risks and decrease mortality maximizing the time allocated to foraging behaviours. Mobility and territory size are likely to affect an individuals' ability to respond adaptively to local speed limits.

A comparative analysis between NACA 4412 airfoil and it's modified form with tubercles

NASA Astrophysics Data System (ADS)

Hasan, Md. Jonayed; Islam, Md. Tazul; Hassan, Md. Mehedi

2017-06-01

The effect of tubercles on the leading edge of an airfoil become more vivid at high angle of attacks. The effect of tubercles with large wavelength and small amplitude on the leading edge of a NACA 4412 airfoil section was investigated numerically and experimentally. The phenomena of improving the airfoil performance by modifying the contours drove our interest to do this analysis. The models were developed & numerical simulations were carried out with both NACA 4412 airfoil and modified airfoil model at Re=1.03×106 and angles of attack ranging from 0° to 20°. Flow separation was analyzed with vector profiles. CL, CD at different angle of attacks was developed and it gave down noticeable pre-stall & post-stall behavior. The airfoils were studied experimentally in a low speed wind tunnel. Pressure distribution over the two airfoils was obtained. It was evident from the pressure distributions that the modified airfoil exhibits significant aerodynamic performance at high angles of attack. We can infer that these effects will be advantageous for maneuverability and post-stall behavior.

Prediction of SA 349/2 GV blade loads in high speed flight using several rotor analyses

NASA Technical Reports Server (NTRS)

Gaubert, Michel; Yamauchi, Gloria K.

1987-01-01

The influence of blade dynamics, dynamic stall, and transonic aerodynamics on the predictions of rotor loads in high-speed flight are presented. Data were obtained from an Aerospatiale Gazelle SA 349/2 helicopter with three Grande Vitesse blades. Several analyses are used for this investigation. First, blade dynamics effects on the correlation are studied using three rotor analyses which differ mainly in the method of calculating the blade elastic response. Next, an ONERA dynamic stall model is used to predict retreating blade stall. Finally, advancing blade aerodynamic loads are calculated using a NASA-developed rotorcraft analysis coupled with two transonic finite-difference analyses.

Measurements of Free-Space Oscillating Pressures Near Propellers at Flight Mach Numbers to 0.72

NASA Technical Reports Server (NTRS)

Kurbjun, Max C; Vogeley, Arthur W

1958-01-01

In the course of a short flight program initiated to check the theory of Garrick and Watkins (NACA rep. 1198), a series of measurements at three stations were made of the oscillating pressures near a tapered-blade plan-form propeller and rectangular-blade plan form propeller at flight Mach numbers up to 0.72. In contradiction to the results for the propeller studied in NACA rep. 1198, the oscillating pressures in the plane ahead of the propeller were found to be higher than those immediately behind the propeller. Factors such as variation in torque and thrust distribution, since the blades of the present investigation were operating above their design forward speed, may account for this contradiction. The effect of blade plan form shows that a tapered-blade plan-form propeller will produce lower sound-pressure levels than a rectangular-blade plan-form propeller for the low blade-passage harmonics (the frequencies where structural considerations are important) and produce higher sound-pressure levels for the higher blade-passage harmonics (frequencies where passenger comfort is important).

Modeling Compressibility Effects in High-Speed Turbulent Flows

NASA Technical Reports Server (NTRS)

Sarkar, S.

2004-01-01

Man has strived to make objects fly faster, first from subsonic to supersonic and then to hypersonic speeds. Spacecraft and high-speed missiles routinely fly at hypersonic Mach numbers, M greater than 5. In defense applications, aircraft reach hypersonic speeds at high altitude and so may civilian aircraft in the future. Hypersonic flight, while presenting opportunities, has formidable challenges that have spurred vigorous research and development, mainly by NASA and the Air Force in the USA. Although NASP, the premier hypersonic concept of the eighties and early nineties, did not lead to flight demonstration, much basic research and technology development was possible. There is renewed interest in supersonic and hypersonic flight with the HyTech program of the Air Force and the Hyper-X program at NASA being examples of current thrusts in the field. At high-subsonic to supersonic speeds, fluid compressibility becomes increasingly important in the turbulent boundary layers and shear layers associated with the flow around aerospace vehicles. Changes in thermodynamic variables: density, temperature and pressure, interact strongly with the underlying vortical, turbulent flow. The ensuing changes to the flow may be qualitative such as shocks which have no incompressible counterpart, or quantitative such as the reduction of skin friction with Mach number, large heat transfer rates due to viscous heating, and the dramatic reduction of fuel/oxidant mixing at high convective Mach number. The peculiarities of compressible turbulence, so-called compressibility effects, have been reviewed by Fernholz and Finley. Predictions of aerodynamic performance in high-speed applications require accurate computational modeling of these "compressibility effects" on turbulence. During the course of the project we have made fundamental advances in modeling the pressure-strain correlation and developed a code to evaluate alternate turbulence models in the compressible shear layer.

Longitudinal Stability and Control Characteristics of a Semispan Model of the XF7U-1 Tailless Airplane at Transonic Speeds by the NACA Wing-Flow Method, TED No. NACA DE307

NASA Technical Reports Server (NTRS)

Sawyer, Richard H.; Trant, James P., Jr.

1947-01-01

An investigation was made by the NACA wing-flow method to determine the longitudinal stability and control characteristics at transonic speeds of a semispan model of the XF7U-1 tailless airplane. The 25-percent chord line of the wing of the model was swept back 35 deg. The airfoil sections of the wing perpendicular to the 25-percent chord line were 12 percent thick. Measurements were made of the normal force and pitching moment through an angle-of-attack range from about -3 deg to 14 deg for several ailavator deflections at Mach numbers from 0.65 to about 1.08. The results of the tests indicated no adverse effects of compressibility up to a Mach number of at least 0.85 at low normal-force coefficients and small ailavator deflections. Up to a Mach number of 0.85, the neutral point at low normal-force coefficients was at about 25 percent of the mean aerodynamic chord and moved rearward irregularly to 41 or 42 percent with a further increase in Mach number to about 1.05. For deflections up to -8.0 percent, the ailavator was effective in changing the pitching moment except at Mach numbers from 0.93 to about 1.0 where ineffectiveness or reversal was indicated for deflections and normal-force coefficients. With -13.2 deg deflection at normal-force coefficients above about 0.3, reversal of ailavator effectiveness occurred at Mach numbers as low as 0.81. A nose-down trim change, which began at a Mach number of about 0.85, together with the loss in effectiveness of the ailavator, indicated that with increase in the Mach number from about 0.95 to 1.05 an abrupt ailavator movement of 5 deg or 6 deg first up and then down would be required to maintain level flight.

Flight Tests of N.A.C.A. Nose-slot Cowlings on the BFC-1 Airplane

NASA Technical Reports Server (NTRS)

Stickle, George W

1939-01-01

The results of flight tests of four nose-slot cowling designs with several variations in each design are presented. The tests were made in the process of developing the nose-slot cowling. The results demonstrate that a nose-slot cowling may be successfully applied to an airplane and that it utilizes the increased slipstream velocity of low-speed operation to produce increased cooling pressure across the engine. A sample design calculation using results from wind-tunnel, flight, and ground tests is given in an appendix to illustrate the design procedure.

Introduction of the M-85 high-speed rotorcraft concept

NASA Technical Reports Server (NTRS)

Stroub, Robert H.

1991-01-01

As a result of studying possible requirements for high-speed rotorcraft and studying many high-speed concepts, a new high-speed rotorcraft concept, designated as M-85, was derived. The M-85 is a helicopter that is reconfigured to a fixed-wing aircraft for high-speed cruise. The concept was derived as an approach to enable smooth, stable conversion between fixed-wing and rotary-wing while retaining hover and low-speed flight characteristics of a low disk loading helicopter. The name, M-85, reflects the high-speed goals of 0.85 Mach number at high altitude. For a high-speed rotorcraft, it is expected that a viable concept must be a cruise-efficient, fixed-wing aircraft so it may be attractive for a multiplicity of missions. It is also expected that a viable high-speed rotorcraft concept must be cruise efficient first and secondly, efficient in hover. What makes the M-85 unique is the large circular hub fairing that is large enough to support the aircraft during conversion between rotary-wind and fixed-wing modes. With the aircraft supported by this hub fairing, the rotor blades can be unloaded during the 100 percent change in rotor rpm. With the blades unloaded, the potential for vibratory loads would be lessened. In cruise, the large circular hub fairing would be part of the lifting system with additional lifting panels deployed for better cruise efficiency. In hover, the circular hub fairing would slightly reduce lift potential and/or decrease hover efficiency of the rotor system. The M-85 concept is described and estimated forward flight performance characteristics are presented in terms of thrust requirements and L/D with airspeed. The forward flight performance characteristics reflect recent completed wind tunnel tests of the wing concept. Also presented is a control system technique that is critical to achieving low oscillatory loads in rotary-wing mode. Hover characteristics, C(sub p) versus C(sub T) from test data, is discussed. Other techniques pertinent to

D-558-2 pilot entry from P2B-1S mothership

NASA Technical Reports Server (NTRS)

1954-01-01

This 28-second video clip shows Scott Crossfield descending from the bomb bay of the P2B-1S into the cockpit of the D-558-2, strapping in, and having the hatch closed by a crewmember. The Douglas D-558-2 Skyrocket airplanes were among the early transonic research airplanes like the X-1, X-4, X-5, and X-92A. Three of these single-seat, swept-wing aircraft flew from 1948 to 1956 in a joint program involving the National Advisory Committee for Aeronautics (NACA); the Navy-Marine Corps; and the Douglas Aircraft Company, Long Beach, California. Flight research was done at the NACA Muroc Flight Test Unit in California, redesignated in 1949 the High-Speed Flight Research Station (HSFRS). The HSFRS is now known as the NASA Dryden Flight Research Center, Edwards, California. The Skyrocket made aviation history when it became the first airplane to fly twice the speed of sound. Douglas Aircraft pilot John F. Martin made the first flight at Muroc Army Airfield (later renamed Edwards Air Force Base) in California on February 4, 1948. The goals of that program were to investigate the characteristics of swept-wing aircraft at transonic and supersonic speeds with particular attention to pitchup (uncommanded rotation of the nose of the airplane upwards) -- a problem prevalent in high-speed service aircraft of that era, particularly at low speeds during takeoff and landing and in tight turns. The three aircraft gathered a great deal of data about pitchup and the coupling of lateral (yaw) and longitudinal (pitch) motions; wing and tail loads, lift, drag, and buffeting characteristics of swept-wing aircraft at transonic and supersonic speeds; and the effects of the rocket exhaust plume on lateral dynamic stability throughout the speed range. (Plume effects were a new experience for aircraft.) The number three aircraft also gathered information about the effects of external stores (bomb shapes, drop tanks) upon the aircraft behavior in the transonic region (roughly 0.7 to 1.3 times the

Performance of NACA Eight-stage Axial-flow Compressor Designed on the Basis of Airfoil Theory

NASA Technical Reports Server (NTRS)

Sinnette, John T; Schey, Oscar W; King, J Austin

1943-01-01

The NACA has conducted an investigation to determine the performance that can be obtained from a multistage axial-flow compressor based on airfoil research. A theory was developed; an eight-stage axial-flow compressor was designed, constructed, and tested. The performance of the compressor was determined for speeds from 5000 to 14,000 r.p.m with varying air flow at each speed. Most of the tests were made with air at room temperature. The performance was determined in accordance with the Committee's recommended procedure for testing superchargers. The expected performance was obtained, showing that a multistage compressor of high efficiency can be designed by the application of airfoil theory.

Coordinating Council. Fourth Meeting: NACA Documents Database Project

NASA Technical Reports Server (NTRS)

1991-01-01

This NASA Scientific and Technical Information Coordination Council meeting dealt with the topic 'NACA Documents Database Project'. The following presentations were made and reported on: NACA documents database project study plan, AIAA study, the Optimal NACA database, Deficiencies in online file, NACA documents: Availability and Preservation, the NARA Collection: What is in it? and What to do about it?, and NACA foreign documents and availability. Visuals are available for most presentations.

X-4 with Pilot Joe Walker, Preflight Briefing

NASA Technical Reports Server (NTRS)

1952-01-01

In this 1952 photograph NACA test pilot Joe Walker (on left) is seen discussing tests points to be flown on the X-4 aircraft with NACA research engineer Donald Bellman. The X-4 Bantam, a single-place, low swept-wing, semi-tailless aircraft, was designed and built by Northrop Aircraft, Inc. It had no horizontal tail surfaces and its mission was to obtain in-flight data on the stability and control of semi-tailless aircraft at high subsonic speeds. The Northrop X-4, Bantam, was a single-place, swept-wing, semi-tailless airplane designed and built to investigate that configuration at transonic speeds (defined as speeds just below and just above the speed of sound, but in this case, the testing was done primarily at just below the speed of sound). The hope of some aerodynamicists was that eliminating the horizontal tail would also do away with stability problems at transonic speeds resulting from the interaction of supersonic shock waves from the wings and the horizontal stabilizers. Northrop Aircraft, Inc. built two X-4 aircraft, the first of which proved to be mechanically unsound. However, ship number 2, with a thicker trailing edge on the wings and elevon, was very reliable. Ship 1 was then grounded and used as parts for ship 2. While being tested from 1950 to 1953 at the NACA High-Speed Flight Research Station (predecessor of today's NASA Dryden Flight Research Center, Edwards, California), the X-4's semi-tailless configuration exhibited inherent longitudinal stability problems (porpoising) as it approached the speed of sound. The X-4 was a small twinjet-engine airplane that had no horizontal tail surfaces, depending instead on combined elevator and aileron control surfaces (called elevons) for control in pitch and roll attitudes. Data gathered from the aircraft's blunt elevon research were helpful in the design of the Bell X-2, which had ailerons with blunted trailing edges. The NACA X-4 program also provided substantial data on the interactions of combined

E-959

NASA Image and Video Library

1953-04-27

The aircraft in this 1953 photo of the National Advisory Committee for Aeronautics (NACA) hangar at South Base of Edwards Air Force Base showed the wide range of research activities being undertaken. On the left side of the hanger are the three D-558-2 research aircraft. These were designed to test swept wings at supersonic speeds approaching Mach 2. The front D-558-2 is the third built (NACA 145/Navy 37975). It has been modified with a leading-edge chord extension. This was one of a number of wing modifications, using different configurations of slats and/or wing fences, to ease the airplane's tendency to pitch-up. NACA 145 had both a jet and a rocket engine. The middle aircraft is NACA 144 (Navy 37974), the second built. It was all-rocket powered, and Scott Crossfield made the first Mach 2 flight in this aircraft on November 20, 1953. The aircraft in the back is D-558-2 number 1. NACA 143 (Navy 37973) was also carried both a jet and a rocket engine in 1953. It had been used for the Douglas contractor flights, then was turned over to the NACA. The aircraft was not converted to all-rocket power until June 1954. It made only a single NACA flight before NACA's D-558-2 program ended in 1956. Beside the three D-558-2s is the third D-558-1. Unlike the supersonic D-558-2s, it was designed for flight research at transonic speeds, up to Mach 1. The D-558-1 was jet-powered, and took off from the ground. The D-558-1's handling was poor as it approached Mach 1. Given the designation NACA 142 (Navy 37972), it made a total of 78 research flights, with the last in June 1953. In the back of the hangar is the X-4 (Air Force 46-677). This was a Northrop-built research aircraft which tested a swept wing design without horizontal stabilizers. The aircraft proved unstable in flight at speeds above Mach 0.88. The aircraft showed combined pitching, rolling, and yawing motions, and the design was considered unsuitable. The aircraft, the second X-4 built, was then used as a pilot traine

The Enlarged N.A.C.A. Tank, and Some of Its Work

NASA Technical Reports Server (NTRS)

Truscott, Starr

1939-01-01

The most conspicuous of the features of the enlarged N.A.C.A. tank are derived directly from those of the original tank and owe their present form not only to the reasons for their first use but also to the experience obtained with them. As in the original tank, there are: 1) A basin of great length (new 2,880 feet); 2) Rails made of structural H beams, without machining; 3) A towing carriage of very high speed (now 80 mph maximum); 4) Rubber tires on all the wheels, pneumatic on the running wheels and solid on the guide wheels.

NACA Researcher Sets up a Test of a New Seat Design

NASA Image and Video Library

1954-05-21

A researcher at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory prepares for a test of an NACA-designed aircraft seat. The laboratory had undertaken a multi-year investigation into the causes and prevention of fires on low altitude aircraft crashes. The program was expanded in the mid-1950s to include the study of impact on passengers, types of seat restraints, and seat design. The crash impact portion of the program began by purposely wrecking surplus Fairchild C-82 Packet and Piper Cub aircraft into barricades at the end of a test runway at the Ravenna Arsenal, located approximately 40 miles south of the Lewis lab in Cleveland. Instrumented dummies and cameras were installed in the pilot and passenger areas. After determining the different loads and their effects on the passengers, the NACA researchers began designing new types of seats and restraints. The result was an elastic seat that flexed upon impact, absorbing 75 percent of the loads before it slowly recoiled. This photograph shows the seats mounted on a pendulum with a large spring behind the platform to provide the jolt that mimicked the forces of a crash. The seat was constructed without any potentially damaging metal parts and included rubber-like material, an inflated back and arms, and a seat cushion. After the pendulum tests, the researchers compared the flexible seats to the rigid seats during a crash of a transport aircraft. They found the passengers in the rigid seats received 66 percent higher g-forces than the NACA-designed seats.

Effects of Vehicle Speed on Flight Initiation by Turkey Vultures: Implications for Bird-Vehicle Collisions

PubMed Central

DeVault, Travis L.; Blackwell, Bradley F.; Seamans, Thomas W.; Lima, Steven L.; Fernández-Juricic, Esteban

2014-01-01

The avoidance of motorized vehicles is a common challenge for birds in the modern world. Birds appear to rely on antipredator behaviors to avoid vehicles, but modern vehicles (automobiles and aircraft) are faster than natural predators. Thus, birds may be relatively ill-equipped, in terms of sensory capabilities and behaviors, to avoid vehicles. We examined the idea that birds may be unable to accurately assess particularly high speeds of approaching vehicles, which could contribute to miscalculations in avoidance behaviors and ultimately cause collisions. We baited turkey vultures (Cathartes aura) to roads with animal carcasses and measured flight initiation distance and effective time-to-collision in response to a truck driving directly towards vultures from a starting distance of 1.13 km and at one of three speeds: 30, 60, or 90 kph (no vultures were struck). Flight initiation distance of vultures increased by a factor of 1.85 as speed increased from 30 to 90 kph. However, for 90-kph approaches there was no clear trend in flight initiation distance across replicates: birds appeared equally likely to initiate escape behavior at 40 m as at 220 m. Time-to-collision decreased by a factor of 0.62 with approach speeds from 30 to 90 kph. Also, at 90 kph, four vehicle approaches (17%) resulted in near collisions with vultures (time-to-collision ≤1.7 s), compared to none during 60 kph approaches and one during 30 kph approaches (4%). Our findings suggest that antipredator behaviors in turkey vultures, particularly stimulus processing and response, might not be well tuned to vehicles approaching at speeds ≥90 kph. The possible inability of turkey vultures to react appropriately to high-speed vehicles could be common among birds, and might represent an important determinant of bird-vehicle collisions. PMID:24503622

HIGH SPEED GC/MS FOR AIR ANALYSIS

EPA Science Inventory

A high speed GC/MS system consisting of a gas chromatograph equipped with a narrow bandwidth injection accessory and using a time-of-flight mass spectrometer detector has been adapted for analysis of ambient whole air samples which have been collected in passivated canisters. ...

Tank Tests of NACA Model 40 Series of Hulls for Small Flying Boats and Amphibians

NASA Technical Reports Server (NTRS)

Parkinson, John B; Dawson, John R

1937-01-01

The NACA model 40 series of flying-boat hull models consists of 2 forebodies and 3 afterbodies combined to provide several forms suitable for use in small marine aircraft. One forebody is the usual form with hollow bow sections and the other has a bottom surface that is completely developable from bow to step. The afterbodies include a short pointed afterbody with an extension for the tail surfaces, a long afterbody similar to that of a seaplane float but long enough to carry the tail surfaces, and a third obtained by fitting a second step in the latter afterbody. The various combinations were tested in the NACA Tank by the general method over a suitable range of loadings. Fixed-trim tests were made for all speeds likely to be used and free-to-trim tests were made at low speeds to slightly beyond the hump speed. The characteristics of the hulls at best trim angles have been deduced from the data of the tests at fixed trim angles and are given in the form of nondimensional coefficients applicable to any size hull.

ARC-1957-A-22640

NASA Image and Video Library

1957-05-01

NACA Photographer North American F-100A (NACA-200) Super Sabre Airplane take-off. The blowing-tupe boundary-layer control on the leading- and trailing-edge provided large reductions in takeoff and landing approach speeds. Approach speeds were reduced by about 10 knots (Mar 1960). Note: Used in publication in Flight Research at Ames; 57 Years of Development and Validation of Aeronautical Technology NASA SP-1998-3300 fig. 102 and and Memoirs of a Flight Test Engneer NASA SP-2002-4525

Investigation of the NACA 4-(3)(8)-045 Two-blade Propellers at Forward Mach Numbers to 0.725 to Determine the Effects of Compressibility and Solidity on Performance

NASA Technical Reports Server (NTRS)

Stack, John; Draley, Eugene C; Delano, James B; Feldman, Lewis

1950-01-01

As part of a general investigation of propellers at high forward speeds, tests of two 2-blade propellers having the NACA 4-(3)(8)-03 and NACA 4-(3)(8)-45 blade designs have been made in the Langley 8-foot high-speed tunnel through a range of blade angle from 20 degrees to 60 degrees for forward Mach numbers from 0.165 to 0.725 to establish in detail the changes in propeller characteristics due to compressibility effects. These propellers differed primarily only in blade solidity, one propeller having 50 percent and more solidity than the other. Serious losses in propeller efficiency were found as the propeller tip Mach number exceeded 0.91, irrespective of forward speed or blade angle. The magnitude of the efficiency losses varied from 9 percent to 22 percent per 0.1 increase in tip Mach number above the critical value. The range of advance ratio for peak efficiency decreased markedly with increase of forward speed. The general form of the changes in thrust and power coefficients was found to be similar to the changes in airfoil lift coefficient with changes in Mach number. Efficiency losses due to compressibility effects decreased with increase of blade width. The results indicated that the high level of propeller efficiency obtained at low speeds could be maintained to forward sea-level speeds exceeding 500 miles per hour.

Scott Crossfield - Portraits

NASA Technical Reports Server (NTRS)

1954-01-01

Albert Scott Crossfield joined the U.S. Navy and was commissioned an ensign in 1943. After completing his military flight training, he served as a fighter and gunnery instructor and maintenance officer before spending six months overseas. He did not see combat duty, but flew such aircraft as the F6F and F4U fighters. Crossfield attended the University of Washington, receiving a Bachelor degree in aeronautical engineering in 1949 and a Masters in aeronautical engineering the following year. He joined the National Advisory Committee for Aeronautics as a pilot at the High-Speed Flight Research Station in June 1950. For the next five years Crossfield flew high speed jets and rocket planes for NACA, including the Bell X-1#2 (10 flights, first on April 20, 1951), Douglas D-558-I #3 Skystreak (15 flights, first on November 29, 1950), D-558-II #2 (53 flights, first on September 28, 1951), D-558-II #3 Skyrocket (36 flights, first on December 22, 1950), Northrop X-4 (29 flights, first on December 6, 1950), Bell X-5 (10 flights, first on April 3, 1952), Convair XF-92A (25 flights, first on April 9, 1953), and the F-100. On November 20, 1953, Crossfield made the first piloted Mach 2 flight in the D-558-II Skyrocket. Crossfield left NACA in December 1955 to join North American Aviation. North American won the competition to build the X-15 a high altitude, high speed piloted research aircraft.

Flight Test Hazard Planning Near the Speed of Light

NASA Technical Reports Server (NTRS)

Henwood, Bart; Huete, Rod

2007-01-01

A viewgraph presentation describing flight test safety near the speed of light is shown. The topics include: 1) Concept; 2) Portal Content; 3) Activity to Date; 4) FTS Database Updatd FAA Program; 5) FAA Flight Test Risk Management; 6) CFR 14 Part 21.35 Current and proposed changes; 7) An Online Resource for Flight Test Safety Planning; 8) Data Gathering; 9) NTPS Role; 10) Example Maturation; 11) Many Varied Inputs; 12) Matured Stall Hazards; 13) Loss of Control Mitigations; 14) FAA Access; 15) NASA PBMA Website Link; 16) FAR Reference Search; 17) Record Field Search; 18) Keyword Search; and 19) Results of FAR Reference Search.

Buffeting of NACA 0012 airfoil at high angle of attack

NASA Astrophysics Data System (ADS)

Zhou, Tong; Dowell, Earl

2014-11-01

Buffeting is a fluid instability caused by flow separation or shock wave oscillations in the flow around a bluff body. Typically there is a dominant frequency of these flow oscillations called Strouhal or buffeting frequency. In prior work several researchers at Duke University have noted the analogy between the classic Von Karman Vortex Street behind a bluff body and the flow oscillations that occur for flow around a NACA 0012 airfoil at sufficiently large angle of attack. Lock-in is found for certain combinations of airfoil oscillation (pitching motion) frequencies and amplitudes when the frequency of the airfoil motion is sufficiently close to the buffeting frequency. The goal of this paper is to explore the flow around a static and an oscillating airfoil at high angle of attack by developing a method for computing buffet response. Simulation results are compared with experimental data. Conditions for the onset of buffeting and lock-in of a NACA 0012 airfoil at high angle of attack are determined. Effects of several parameters on lift coefficient and flow response frequency are studied including Reynolds number, angle of attack and blockage ratio of the airfoil size to the wind tunnel dimensions. Also more detailed flow field characteristics are determined. For a static airfoil, a universal Strouhal number scaling has been found for angles of attack from 30° to 90°, where the flow around airfoil is fully separated. For an oscillating airfoil, conditions for lock-in are discussed. Differences between the lock-in case and the unlocked case are also studied. The second affiliation: Duke University.

Tu-144LL SST Flying Laboratory Lifts off Runway on a High-Speed Research Flight

NASA Technical Reports Server (NTRS)

1998-01-01

eight were selected, including six flight and two ground (engine) tests. The flight experiments included studies of the aircraft's exterior surface, internal structure, engine temperatures, boundary-layer airflow, the wing's ground-effect characteristics, interior and exterior noise, handling qualities in various flight profiles, and in-flight structural flexibility. The ground tests studied the effect of air inlet structures on airflow entering the engine and the effect on engine performance when supersonic shock waves rapidly change position in the engine air inlet. A second phase of testing further studied the original six in-flight experiments with additional instrumentation installed to assist in data acquisition and analysis. A new experiment aimed at measuring the in-flight deflections of the wing and fuselage was also conducted. American-supplied transducers and sensors were installed to measure nose boom pressures, angle of attack, and sideslip angles with increased accuracy. Two NASA pilots, Robert Rivers of Langley Research Center, Hampton, Virginia, and Gordon Fullerton from Dryden Flight Research Center, Edwards, California, assessed the aircraft's handling at subsonic and supersonic speeds during three flight tests in September 1998. The program concluded after four more data-collection flights in the spring of 1999. The Tu-144LL model had new Kuznetsov NK-321 turbofan engines rated at more than 55,000 pounds of thrust in full afterburner. The aircraft is 215 feet, 6 inches long and 42 feet, 2 inches high with a wingspan of 94 feet, 6 inches. The aircraft is constructed mostly of light aluminum alloy with titanium and stainless steel on the leading edges, elevons, rudder, and the under-surface of the rear fuselage.

Investigation of the Characteristics of a High-Aspect-Ratio Wing in the Langley 8-Foot High-Speed Tunnel

NASA Technical Reports Server (NTRS)

Whitcomb, Richard T.

1940-01-01

An investigation of the characteristics of a wing with an aspect ratio of 9.0 and an NACA 65-210 airfoil section has been made at Mach number up to 0.925. The wing tested has a taper ratio of 2.5:1.0, no twist, dihedral, or sweepback, and 20-percent - chord 37.5-percent-semispan plain ailerons. The results showed that serious changes in the normal-force characteristics occurred when the Mach number was increased above 0.74 at angles of attack between 4 deg. and 10 deg. and above 0.80 at 0 deg. angle of attack.Because of small outboard shifts in the lateral center of load, the bending moment at the root for conditions corresponding to a 3g pull-out at an altitude of 35,000 feet increased by approximately 5% when the Much number was increased beyond 0.83 the negative pitching moments for the high angles of attack increased, whereas those for the low angles of attack decreased with a resulting large increase in the negative slope of the pitching-moment curves. A large increase occurred in the values of the drag coefficients for the range of lift coefficients needed for level flight at an altitude of 35,000 feet when the Mach number was increased beyond a value of 0.80. The wakes at a station 2.82 root chords behind the wing quarter-chord line extended approximately a chord above the wing chord line for the angles of attack required to recover from high-speed dives at high Mach numbers.

High-Altitude Flight Cooling Investigation of a Radial Air-Cooled Engine

NASA Technical Reports Server (NTRS)

Manganiello, Eugene J; Valerino, Michael F; Bell, E Barton

1947-01-01

An investigation of the cooling of an 18-cylinder, twin-row, radial, air-cooled engine in a high-performance pursuit airplane has been conducted for variable engine and flight conditions at altitudes ranging from 5000 to 35,000 feet in order to provide a basis for predicting high-altitude cooling performance from sea-level or low altitude experimental results. The engine cooling data obtained were analyzed by the usual NACA cooling-correlation method wherein cylinder-head and cylinder-barrel temperatures are related to the pertinent engine and cooling-air variables. A theoretical analysis was made of the effect on engine cooling of the change of density of the cooling air across the engine (the compressibility effect), which becomes of increasing importance as altitude is increased. Good agreement was obtained between the results of the theoretical analysis and the experimental data.

An Investigation of the Drag and Pressure Recovery of a Submerged Inlet and a Nose Inlet in the Transonic Flight Range with Free-fall Models

NASA Technical Reports Server (NTRS)

Selna, James; Schlaff, Bernard A

1951-01-01

The drag and pressure recovery of an NACA submerged-inlet model and an NACA series I nose-inlet model were investigated in the transonic flight range. The tests were conducted over a mass-flow-ratio range of 0.4 to 0.8 and a Mach number range of about 0.8 to 1.10 employing large-scale recoverable free-fall models. The results indicate that the Mach number of drag divergence of the inlet models was about the same as that of a basic model without inlets. The external drag coefficients of the nose-inlet model were less than those of the submerged-inlet model throughout the test range. The difference in drag coefficient based on the maximum cross-sectional area of the models was about 0.02 at supersonic speeds and about 0.015 at subsonic speeds. For a hypothetical airplane with a ratio of maximum fuselage cross-sectional area to wing area of 0.06, the difference in airplane drag coefficient would be relatively small, about 0.0012 at supersonic speeds and about 0.0009 at subsonic speeds. Additional drag comparisons between the two inlet models are made considering inlet incremental and additive drag.

Preliminary Investigation in the NACA Low-Turbulence Tunnel of Low-drag Airfoil Sections Suitable for Admitting Air at the Leading Edge

NASA Technical Reports Server (NTRS)

von Doenhoff, Albert E.; Horton, Elmer A.

1942-01-01

An investigation was carried out in the NACA low-turbulence tunnel to develop low-drag airfoil sections suitable for admitting air at the leading edge. A thickness distribution having the desired type of pressure distribution was found from tests of a flexible model. Other airfoil shapes were derived from this original shape by varying the thickness, the camper, the leading-edge radius, and the size of the leading-edge opening. Data are presented giving the characteristics of the airfoil shapes in the range of lift coefficients for high-speed and cruising flight. Shapes have been developed which show no substantial increases in drag over that of the same position along the chord. Many of these shapes appear to have higher critical compressibility speeds than plain airfoils of the same thickness. Low-drag airfoil sections have been developed with openings in the leading edge as large as 41.5 percent of the maximum thickness. The range of lift coefficients for low drag in several cases is nearly as large as that of the corresponding plain airfoil sections. Preliminary measurements of maximum lift characteristics indicate that nose-opening sections of the type herein considered may not produce any marked effects on the maximum lift coefficient.

Static and dynamic pressure measurements on a NACA 0012 airfoil in the Ames High Reynolds Number Facility

NASA Technical Reports Server (NTRS)

Mcdevitt, J. B.; Okuno, A. F.

1985-01-01

The supercritical flows at high subsonic speeds over a NACA 0012 airfoil were studied to acquire aerodynamic data suitable for evaluating numerical-flow codes. The measurements consisted primarily of static and dynamic pressures on the airfoil and test-channel walls. Shadowgraphs were also taken of the flow field near the airfoil. The tests were performed at free-stream Mach numbers from approximately 0.7 to 0.8, at angles of attack sufficient to include the onset of buffet, and at Reynolds numbers from 1 million to 14 million. A test action was designed specifically to obtain two-dimensional airfoil data with a minimum of wall interference effects. Boundary-layer suction panels were used to minimize sidewall interference effects. Flexible upper and lower walls allow test-channel area-ruling to nullify Mach number changes induced by the mass removal, to correct for longitudinal boundary-layer growth, and to provide contouring compatible with the streamlines of the model in free air.

Measurements in Flight of the Flying Qualities of a Chance Vought F4U-4 Airplane: TED No. NACA 2388

NASA Technical Reports Server (NTRS)

Liddell, Charles J., Jr.; Reynolds, Robert M.; Christofferson, Frank E.

1947-01-01

The results of flight tests to determine flying qualities of a Chance Vought F4U-4 airplane are presented and discussed herein. In addition to comprehensive measurements at low altitude (about 8000 ft), tests of limited scope were made at high altitude (about 25,000 ft). The more important characteristics, based on a comparison of the test results and opinions of the pilots with the Navy requirements, can be summarized as follows: 1. The short-period control-free oscillations of the elevator angle and the normal acceleration were satisfactorily damped. 2. The most rearward center-of-gravity locations for satisfactory static longitudinal stability with power on, as determined by the control-force variations, were approximately 30 and 27 percent M.A.C. with flaps and gear up and down, respectively. 3. In maneuvering flight the conditions for which control-force gradients of satisfactory magnitude were obtained were seriously limited by sizable changes in the gradient with center-of-gravity location, airspeed, altitude, acceleration factor, and direction of turn. 4. The elevator and rudder controls were satisfactory for landings and take-offs. 5. The trim tabs were sufficiently effective for all controls. 6. The directional and lateral dynamic stability was positive, but the rudder oscillation did not damp within one cycle. The airplane oscillation damped sufficiently at low altitude but not at high altitude. 7. Both rudder-fixed and rudder-free static directional stability were positive over a sideslip range of +/-15 deg. However, the rudder force tended to reverse at high angles of right sideslip with flaps and gear up, power on, at low speeds. 8. The stick-fixed static lateral stability (dihedral effect) was positive in all conditions, but the stick-free dihedral effect was neutral at low speeds with flap and gear down, power on. 9. The yaw due to abrupt full aileron deflection at low speed was mot excessive, and the rudder control was adequate to hold trim

The Effectiveness at High Speeds of a 20-Percent-chord Plain Trailing-edge Flap on the NACA 65-210 Airfoil Section

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 flag on the INCA 65-210 airfoil section.

A review of technologies applicable to low-speed flight of high-performance aircraft investigated in the Langley 14- x 22-foot subsonic tunnel

NASA Technical Reports Server (NTRS)

Paulson, John W., Jr.; Quinto, P. Frank; Banks, Daniel W.; Kemmerly, Guy T.; Gatlin, Gregory M.

1988-01-01

An extensive research program has been underway at the NASA Langley Research Center to define and develop the technologies required for low-speed flight of high-performance aircraft. This 10-year program has placed emphasis on both short takeoff and landing (STOL) and short takeoff and vertical landing (STOVL) operations rather than on regular up and away flight. A series of NASA in-house as well as joint projects have studied various technologies including high lift, vectored thrust, thrust-induced lift, reversed thrust, an alternate method of providing trim and control, and ground effects. These technologies have been investigated on a number of configurations ranging from industry designs for advanced fighter aircraft to generic wing-canard research models. Test conditions have ranged from hover (or static) through transition to wing-borne flight at angles of attack from -5 to 40 deg at representative thrust coefficients.

Does the metabolic rate-flight speed relationship vary among geometrically similar birds of different mass?

PubMed

Bundle, Matthew W; Hansen, Kacia S; Dial, Kenneth P

2007-03-01

Based on aerodynamic considerations, the energy use-flight speed relationship of all airborne animals and aircraft should be U-shaped. However, measures of the metabolic rate-flight speed relationship in birds have been available since Tucker's pioneering experiments with budgerigars nearly forty years ago, but this classic work remains the only study to have found a clearly U-shaped metabolic power curve. The available data suggests that the energetic requirements for flight within this species are unique, yet the metabolic power curve of the budgerigar is widely considered representative of birds in general. Given these conflicting results and the observation that the budgerigar's mass is less than 50% of the next smallest species to have been studied, we asked whether large and small birds have metabolic power curves of different shapes. To address this question we measured the rates of oxygen uptake and wingbeat kinematics in budgerigars and cockatiels flying within a variable-speed wind tunnel. These species are close phylogenetic relatives, have similar flight styles, wingbeat kinematics, and are geometrically similar but have body masses that differ by a factor of two. In contrast to our expectations, we found the metabolic rate-flight speed relationship of both species to be acutely U-shaped. We also found that neither budgerigars nor cockatiels used their normal intermittent flight style while wearing a respirometric mask. We conclude that species size differences alone do not explain the previously unique metabolic power curve of the budgerigar; however, due to the absence of comparable data we cannot evaluate whether the mask-related kinematic response we document influences the metabolic rate-flight speed relationship of these parrots, or whether the energetics of flight differ between this and other avian clades.

Electrogenic Na+/Ca2+ Exchange

PubMed Central

Danaceau, Jonathan P.; Lucero, Mary T.

2000-01-01

Olfactory receptor neurons (ORNs) from the squid, Lolliguncula brevis, respond to the odors l-glutamate or dopamine with increases in internal Ca2+ concentrations ([Ca2+]i). To directly asses the effects of increasing [Ca2+]i in perforated-patched squid ORNs, we applied 10 mM caffeine to release Ca2+ from internal stores. We observed an inward current response to caffeine. Monovalent cation replacement of Na+ from the external bath solution completely and selectively inhibited the caffeine-induced response, and ruled out the possibility of a Ca2+-dependent nonselective cation current. The strict dependence on internal Ca2+ and external Na+ indicated that the inward current was due to an electrogenic Na+/Ca2+ exchanger. Block of the caffeine-induced current by an inhibitor of Na+/Ca2+ exchange (50–100 μM 2′,4′-dichlorobenzamil) and reversibility of the exchanger current, further confirmed its presence. We tested whether Na+/Ca2+ exchange contributed to odor responses by applying the aquatic odor l-glutamate in the presence and absence of 2′,4′-dichlorobenzamil. We found that electrogenic Na+/Ca2+ exchange was responsible for ∼26% of the total current associated with glutamate-induced odor responses. Although Na+/Ca2+ exchangers are known to be present in ORNs from numerous species, this is the first work to demonstrate amplifying contributions of the exchanger current to odor transduction. PMID:10828249

X-1E launch from B-50 mothership

NASA Technical Reports Server (NTRS)

1950-01-01

Beginning in 1946, two XS-1 experimental research aircraft (later redesignated X-1s) conducted pioneering tests at Muroc Army Air Field (now Edwards Air Force Base) in California to obtain flight data on conditions in the transonic speed range. These early tests culminated on October 14, 1947, in the first piloted flight faster than Mach 1.0, the speed of sound. During November, 1947, the Air Force authorized studies that led to a contract (W-33-038-ac-20062) with Bell Aircraft to build four (later three) improved X-1 aircraft (the X-1C being cancelled). Designated X-1A (#48-1384), X-1B (#48-1385), and X-1D (#48-1386), the airplanes were ready by late 1950. The aircraft were about five feet longer and 2,500 lbs. heavier than the original X-craft planes. They used the 8-percent wing like the earlier X-craft. The D-model had a low-pressure turbo-pump and the B model was fitted with a prototype hydrogen peroxide reaction control system for later aircraft to use in exoatmospheric research flights. Access was through a lift-off canopy. The planes were finished in their bare metal color and white. The X-1D was ready first, but on what was intended to be its second flight (August 22, 1951) it was jettisoned and crashed at Muroc after an aerial explosion while still mated to its mother (B-50A [#46-006A]) ship. The long-delayed X-1 #3 airplane with the turbine pump was finally completed for the NACA in 1951. It made its first glide flight on July 20, 1951, with NACA pilot Joseph Cannon. Its second and final captive flight was on November 9, 1951. It was destroyed on the ground by an explosion and fire along with its B-50A mother ship while attempting to jettison fuel. The X-1A arrived at Muroc in January, 1953 and had its first powered flight on February 21, 1953. On December 8, 1953 with Yeager as pilot, the aircraft investigated high-speed stability and control issues. The X-1A was turned over to the NACA, but was lost to aerial explosion on August 8, 1955, shortly before

Spatial and mineralogic variation of Na-Ca alteration in Laramide porphyry systems of Arizona

NASA Astrophysics Data System (ADS)

Runyon, S.; Seedorff, E.; Barton, M. D.; Mazdab, F. K.; Lecumberri-Sanchez, P.; Steele-MacInnis, M.

2017-12-01

Na-Ca alteration is characterized by the metasomatic addition of Ca ± Na and the loss of K. Minor volumes of Na-Ca alteration in Laramide porphyry systems develops from 3 to 8 km paleodepth. Mineral assemblages, mineral compositions, hydrogen isotopes, whole-rock analyses, and reconnaissance fluid inclusion characteristics have been documented for Na-Ca alteration in Laramide porphyry systems such as Tea Cup and Sierrita. Volumetrically minor Na-Ca alteration in Laramide porphyry systems documented in this study commonly takes the form of one of three mineral assemblages: albite-epidote-chlorite, Na-plagioclase-actinolite ± epidote, and garnet- or diopside-stable Na-plagioclase-actinolite ± epidote. These different Na-Ca mineral assemblages have broad spatial relationships, from shallow albite-chlorite-epidote to deeper Na-plagioclase-actinolite within a given district. Hydrogen isotope data on Na-Ca alteration minerals shows consistently distinct δD compositions of Na-Ca alteration minerals compared to igneous minerals in a given district. Further, calculated hydrogen isotope composition of fluids in equilibrium with Na-Ca alteration minerals are consistently enriched in δD compared to magmatic-hydrothermal fluids. Whole-rock analyses show consistent losses of K and variable addition of Na and Ca across different Na-Ca alteration assemblages. Na-Ca alteration has been well documented associated with the Jurassic arc. Previous studies demonstrated through mass balance, timing and spatial relationships, isotopic, and fluid inclusion studies that Na-Ca alteration associated with the Jurassic arc likely formed from the circulation of external, highly saline, non-magmatic fluids (e.g., Battles and Barton, 1995; Dilles et al., 1995). Na-Ca alteration documented in Laramide systems is generally similar to Na-Ca alteration documented along the Jurassic arc in mineral assemblages, compositions, and timing, but the volume of Na-Ca alteration in the Laramide systems is

A High-Speed Motion-Picture Study of Normal Combustion, Knock and Preignition in a Spark-Ignition Engines

NASA Technical Reports Server (NTRS)

Rothrock, A M; Spencer, R C; Miller, Cearcy D

1941-01-01

Combustion in a spark-ignition engine was investigated by means of the NACA high-speed motion-picture cameras. This camera is operated at a speed of 40,000 photographs a second and therefore makes possible the study of changes that take place in the intervals as short as 0.000025 second. When the motion pictures are projected at the normal speed of 16 frames a second, any rate of movement shown is slowed down 2500 times. Photographs are presented of normal combustion, of combustion from preignitions, and of knock both with and without preignition. The photographs of combustion show that knock may be preceded by a period of exothermic reaction in the end zone that persists for a time interval of as much as 0.0006 second. The knock takes place in 0.00005 second or less.

NACA Wartime Safety Poster

NASA Image and Video Library

1945-04-21

One of many safety posters produced by NACA artists during World War II. The Aircraft Engine Research Laboratory established a Safety Office in 1942 to coordinate and oversee safety-related activities. The lab struggled to maintain a full staff during the war when military research projects were at a peak. NACA management mandated six-day work weeks without overtime and the elimination of holidays. As such, workplace injuries were a serious threat to maintaining productivity needed to sustain the military’s aeronautics efforts.

Boeing B-47 Bomber with an Ejector at the 1957 NACA Lewis Inspection

NASA Image and Video Library

1957-10-21

A Boeing B-47 Stratojet bomber with a noise-reducing ejector on its engine at the 1957 Inspection of the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. Representatives from the military, aeronautical industry, universities, and the press were invited to the laboratory to be briefed on the NACA’s latest research efforts and tour the state- of- the- art test facilities. Over 1700 people visited the NACA Lewis in Cleveland, Ohio during October 7 - 10, 1957. By the mid-1950s, the aircraft industry was close to introducing jet airliners to the nation’s airways. The noise produced by the large jet engines, however, would pose a considerable problem for communities near airports. This problem was demonstrated at the 1957 Inspection by an NACA Lewis researcher who played longplay (LP) audio records of military jet engines for an audience. Tests showed that the source of the loudest noise was not the engine itself, but the mixing of the engine’s exhaust with the surrounding air in the atmosphere. The pressures resulting from this turbulence produced sound waves. One of Lewis’ first studies sought to design an exhaust nozzle that reduced the turbulence. A Pratt and Whitney J57 was tested in the Altitude Wind Tunnel with many of these nozzle configurations from January to May 1957. Researchers found that the various nozzle types did reduce the noise levels but also reduced the aircraft’s thrust. Afterwards, they determined that the addition of an NACA-developed ejector reduced the noise levels without diminishing thrust.

Drive Fan of the NACA's Icing Research Tunnel

NASA Image and Video Library

1956-10-21

A researcher examines the drive fan inside the Icing Research Tunnel at the National Advisory Committee for Aeronautics (NACA) Flight Propulsion Research Laboratory in Cleveland, Ohio. The facility was built in the mid-1940s to simulate the atmospheric conditions that caused ice to build up on aircraft. Carrier Corporation refrigeration equipment reduced the internal air temperature to -45⁰ F, and a spray bar system injected water droplets into the air stream. The 24-foot diameter drive fan, seen in this photograph, created air flow velocities up to 400 miles per hour. The 1950s were prime years for the Icing Research Tunnel. NACA engineers had spent the 1940s trying to resolve the complexities of the spray bar system. The final system put into operation in 1950 included six horizontal spray bars with 80 nozzles that produced a 4- by 4-foot cloud in the test section. The icing tunnel was used for extensive testing of civilian and military aircraft components in the 1950s. The NACA also launched a major investigation of the various methods of heating leading edge surfaces. The hot-air anti-icing technology used on today’s commercial transports was largely developed in the facility during this period. Lewis researchers also made significant breakthroughs with icing on radomes and jet engines. Although the Icing Research Tunnel yielded major breakthroughs in the 1950s, the Lewis icing research program began tapering off as interest in the space program grew. The icing tunnel’s use declined in 1956 and 1957. The launch of Sputnik in October 1957 signaled the end of the facility’s operation. The icing staff was transferred to other research projects and the icing tunnel was temporarily mothballed.

High speed turboprop aeroacoustic study (counterrotation). Volume 2: Computer programs

NASA Technical Reports Server (NTRS)

Whitfield, C. E.; Mani, R.; Gliebe, P. R.

1990-01-01

The isolated counterrotating high speed turboprop noise prediction program developed and funded by GE Aircraft Engines was compared with model data taken in the GE Aircraft Engines Cell 41 anechoic facility, the Boeing Transonic Wind Tunnel, and in the NASA-Lewis 8 x 6 and 9 x 15 wind tunnels. The predictions show good agreement with measured data under both low and high speed simulated flight conditions. The installation effect model developed for single rotation, high speed turboprops was extended to include counter rotation. The additional effect of mounting a pylon upstream of the forward rotor was included in the flow field modeling. A nontraditional mechanism concerning the acoustic radiation from a propeller at angle of attack was investigated. Predictions made using this approach show results that are in much closer agreement with measurement over a range of operating conditions than those obtained via traditional fluctuating force methods. The isolated rotors and installation effects models were combined into a single prediction program. The results were compared with data taken during the flight test of the B727/UDF (trademark) engine demonstrator aircraft.

High speed turboprop aeroacoustic study (counterrotation). Volume 2: Computer programs

NASA Astrophysics Data System (ADS)

Whitfield, C. E.; Mani, R.; Gliebe, P. R.

1990-07-01

The isolated counterrotating high speed turboprop noise prediction program developed and funded by GE Aircraft Engines was compared with model data taken in the GE Aircraft Engines Cell 41 anechoic facility, the Boeing Transonic Wind Tunnel, and in the NASA-Lewis 8 x 6 and 9 x 15 wind tunnels. The predictions show good agreement with measured data under both low and high speed simulated flight conditions. The installation effect model developed for single rotation, high speed turboprops was extended to include counter rotation. The additional effect of mounting a pylon upstream of the forward rotor was included in the flow field modeling. A nontraditional mechanism concerning the acoustic radiation from a propeller at angle of attack was investigated. Predictions made using this approach show results that are in much closer agreement with measurement over a range of operating conditions than those obtained via traditional fluctuating force methods. The isolated rotors and installation effects models were combined into a single prediction program. The results were compared with data taken during the flight test of the B727/UDF (trademark) engine demonstrator aircraft.

2015 Summer Series - The NACA - A Hundred Year Legacy

NASA Image and Video Library

2015-07-09

Understanding the past provides insight into our identity and NASA's history lies within NACA, the National Advisory Committee for Aeronautics. NACA's culture of conducting cutting edge research became the spirit of NASA and laid the foundation for America's leap into space. NACA was established on March 3, 1915 in order to promote aeronautical research and was the source behind our air superiority during WWII. The Panel delves into the legacy of the NACA.

Effects of Compressibility on the Maximum Lift Characteristics and Spanwise Load Distribution of a 12-Foot-Span Fighter-Type Wing of NACA 230-Series Airfoil Sections

NASA Technical Reports Server (NTRS)

West, F E

1945-01-01

Lift characteristics and pressure distribution for a NACA 230 wing were investigated for an angle of attack range of from -10 to +24 degrees and Mach range of from 0.2 to 0.7. Maximum lift coefficient increased up to a Mach number of 0.3, decreased rapidly to a Mach number of 0.55, and then decreased moderately. At high speeds, maximum lift coefficient was reached at from 10 to 12 degrees beyond the stalling angle. In high-speed stalls, resultant load underwent a moderate shift outward.

A Complete Tank Test of a Model of Flying-boat Hull - N.A.C.A. Model 16

NASA Technical Reports Server (NTRS)

Shoemaker, James H

1933-01-01

A model of a 2-step flying-boat hull, of the type generally used in England, was tested according to the complete method described in the N.A.C.A. Technical Note No. 464. The lines of this model were taken from offsets given by Mr. William Munro in Flight, May 29, 1931. The data cover the range of loads, speeds, and trim angles that may be of use in applying the hull form to the design of any seaplane. The results are reduced to nondimensional form to aid application to design problems and facilitate comparison with the performance of other hulls. The water characteristics of Model 16 are compared with those of Model 11-A, which is representative of current American practice. The results show that when the two forms are applied to a given seaplane design under optimum conditions for each, the performance of Model 16 will be somewhat inferior to that of Model 11-A.

Summary of NACA/NASA Variable-Sweep Research and Development Leading to the F-111 (TFX)

NASA Technical Reports Server (NTRS)

1966-01-01

On November 24, 1962, the United States ushered in a new era of aircraft development when the Department of Defense placed an initial development contract for the world's first supersonic variable-sweep aircraft - the F-111 or so-called TFX (tactical fighter-experimental). The multimission performance potential of this concept is made possible by virtue of the variable-sweep wing - a research development of the NASA and its predecessor, the NACA. With the wing swept forward into the maximum span position, the aircraft configuration is ideal for efficient subsonic flight. This provides long-range combat and ferry mission capability, short-field landing and take-off characteristics, and compatibility with naval aircraft carrier operation. With the wing swept back to about 650 of sweep, the aircraft has optimum supersonic performance to accomplish high-altitude supersonic bombing or interceptor missions. With the wing folded still further back, the aircraft provides low drag and low gust loads during supersonic flight "on the deck" (altitudes under 1000 feet). The concept of wing variable sweep, of course, is not new. Initial studies were conducted at Langley as early as 1945, and two subsonic variable-sweep prototypes (Bell X-5 and Grumman XF-IOF) were flown as early as 1951/52. These were subsonic aircraft, however, and the great advantage of variable sweep in improving supersonic flight efficiency could not be realized. Further the structures of these early aircraft were complicated by the necessity for translating the ing fore and aft to achieve satisfactory longitUdinal stability as the wing sweep was varied. Late in 1958 a research breakthrough at Langley provided the technology for designing a variable-sweep wing having satisfactory stability through a wide sweep angle range without the necessity for fore and aft translation of the wing. In this same period there evolved within the military services an urgent requirement for a versatile fighter-bomber that

Development of Cowling for Long-nose Air-cooled Engine in the NACA Full-scale Wind Tunnel

NASA Technical Reports Server (NTRS)

Guryansky, Eugene R.; Silverstein, Abe

1941-01-01

An investigation of cowlings for long-nose radial engines was made on the Curtiss XP-42 fighter in the NACA full-scale wind tunnel. The unsatisfactory aerodynamic characteristics of all the cowlings with scoop inlets tested led to the development of the annular high-velocity inlet cowlings. Tests showed that ratio of cooling-air velocity at cowling inlet to stream velocity should not be less than 0.5 for this type of cowling and that critical compressibility speed can be extended to more than 500 mph at 20,000 ft altitude.

Selected bibliography of NACA-NASA aircraft icing publications

NASA Technical Reports Server (NTRS)

Reinmann, J. J. (Compiler)

1981-01-01

A summary of NACA-NASA icing research from 1940 to 1962 is presented. It includes: the main results of the NACA icing program from 1940 to 1950; a selected bibliography of 132 NACA-NASA aircraft icing publications; a technical summary of each document cited in the selected bibliography; and a microfiche copy of each document cited in the selected bibliography.

Impact Test of a NACA-Designed Pilot Seat and Harness

NASA Image and Video Library

1955-02-21

This time-lapse photograph shows the test of a pilot seat and restraint designed by researchers at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The laboratory had undertaken a multi-year investigation into the causes and preventative measures for fires resulting from low altitude aircraft crashes. The program was expanded in the mid-1950s to include the study of crash impact on passengers, new types of types of seat restraints, and better seat designs. The impact program began by purposely wrecking surplus transport Fairchild C-82 Packet and Piper Cub aircraft into barricades at the end of a test runway. Instrumented dummies and cameras were installed in the pilot and passenger areas. After determining the different loads experienced during a crash and the effects on the passengers, the NACA researchers began designing new types of seats and restraints. The result was an elastic seat that flexed upon impact, absorbing 75 percent of the loads before it slowly recoiled. This photograph shows the seats mounted on a pendulum with a large spring behind the platform to provide the jolt that mimicked the forces of a crash. The seat was constructed without any potentially damaging metal parts and included rubber-like material, an inflated back and arms, and a seat cushion. After the pendulum tests, the researchers compared the flexible seats to the rigid seats during a crash of a transport aircraft. They found the passengers in the rigid seats received 66 percent higher g-forces than the NACA-designed seats.

Flight Demonstration of a Shock Location Sensor Using Constant Voltage Hot-Film Anemometry

NASA Technical Reports Server (NTRS)

Moes, Timothy R.; Sarma, Garimella R.; Mangalam, Siva M.

1997-01-01

Flight tests have demonstrated the effectiveness of an array of hot-film sensors using constant voltage anemometry to determine shock position on a wing or aircraft surface at transonic speeds. Flights were conducted at the NASA Dryden Flight Research Center using the F-15B aircraft and Flight Test Fixture (FTF). A modified NACA 0021 airfoil was attached to the side of the FTF, and its upper surface was instrumented to correlate shock position with pressure and hot-film sensors. In the vicinity of the shock-induced pressure rise, test results consistently showed the presence of a minimum voltage in the hot-film anemometer outputs. Comparing these results with previous investigations indicate that hot-film anemometry can identify the location of the shock-induced boundary layer separation. The flow separation occurred slightly forward of the shock- induced pressure rise for a laminar boundary layer and slightly aft of the start of the pressure rise when the boundary layer was tripped near the airfoil leading edge. Both minimum mean output and phase reversal analyses were used to identify the shock location.

Hydrodynamic and Aerodynamic Tests of a Family of Models of Seaplane Floats with Varying Angles of Dead Rise - N.A.C.A. Models 57-A, 57-B, and 57-C

NASA Technical Reports Server (NTRS)

Parkinson, John B; Olson, Roland E; House, Rufus O

1939-01-01

Three models of V-bottom floats for twin-float seaplanes (N.A.C.A. models 57-A, 57-B, and 57-C) having angles of dead rise of 20 degrees, 25 degrees, and thirty degrees, respectively, were tested in the N.A.C.A. tank and in the N.A.C.A. 7- by 10-foot wind tunnel. Within the range investigated, the effect of angle of dead rise on water resistance was found to be negligible at speeds up to and including the hump speed, and water resistance was found to increase with angle of dead rise at planing speeds. The height of the spray at the hump speed decreased with increase in angle of dead rise and the aerodynamic drag increased with dead rise. Lengthening the forebody of model 57-B decreased the water resistance and the spray at speeds below the hump speed. Spray strips provided an effective means for the control of spray with the straight V sections used in the series but considerably increased the aerodynamic drag. Charts for the determination of the water resistance and the static properties of the model with 25 degrees dead rise and for the aerodynamic drag of all the models are included for use in design.

M2-F1 in flight during low-speed car tow

NASA Technical Reports Server (NTRS)

1963-01-01

The M2-F1 shown in flight during a low-speed car tow runs across the lakebed. Such tests allowed about two minutes to test the vehicle's handling in flight. NASA Flight Research Center (later redesignated the Dryden Flight Research Center) personnel conducted as many as 8 to 14 ground-tow flights in a single day either to test the vehicle in preparation for air tows or to train pilots to fly the vehicle before they undertook air tows. The wingless, lifting body aircraft design was initially concieved as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with the largest engine available. He took the car to Bill Straup's renowned hot-rod shop near Long Beach for modification. With a special gearbox and racing slicks, the Pontiac could tow the 1,000-pound M2-F1 110 miles per hour in 30

Flying with the wind: scale dependency of speed and direction measurements in modelling wind support in avian flight.

PubMed

Safi, Kamran; Kranstauber, Bart; Weinzierl, Rolf; Griffin, Larry; Rees, Eileen C; Cabot, David; Cruz, Sebastian; Proaño, Carolina; Takekawa, John Y; Newman, Scott H; Waldenström, Jonas; Bengtsson, Daniel; Kays, Roland; Wikelski, Martin; Bohrer, Gil

2013-01-01

Understanding how environmental conditions, especially wind, influence birds' flight speeds is a prerequisite for understanding many important aspects of bird flight, including optimal migration strategies, navigation, and compensation for wind drift. Recent developments in tracking technology and the increased availability of data on large-scale weather patterns have made it possible to use path annotation to link the location of animals to environmental conditions such as wind speed and direction. However, there are various measures available for describing not only wind conditions but also the bird's flight direction and ground speed, and it is unclear which is best for determining the amount of wind support (the length of the wind vector in a bird's flight direction) and the influence of cross-winds (the length of the wind vector perpendicular to a bird's direction) throughout a bird's journey. We compared relationships between cross-wind, wind support and bird movements, using path annotation derived from two different global weather reanalysis datasets and three different measures of direction and speed calculation for 288 individuals of nine bird species. Wind was a strong predictor of bird ground speed, explaining 10-66% of the variance, depending on species. Models using data from different weather sources gave qualitatively similar results; however, determining flight direction and speed from successive locations, even at short (15 min intervals), was inferior to using instantaneous GPS-based measures of speed and direction. Use of successive location data significantly underestimated the birds' ground and airspeed, and also resulted in mistaken associations between cross-winds, wind support, and their interactive effects, in relation to the birds' onward flight. Wind has strong effects on bird flight, and combining GPS technology with path annotation of weather variables allows us to quantify these effects for understanding flight behaviour. The

The concurrent validity and reliability of a low-cost, high-speed camera-based method for measuring the flight time of vertical jumps.

PubMed

Balsalobre-Fernández, Carlos; Tejero-González, Carlos M; del Campo-Vecino, Juan; Bavaresco, Nicolás

2014-02-01

Flight time is the most accurate and frequently used variable when assessing the height of vertical jumps. The purpose of this study was to analyze the validity and reliability of an alternative method (i.e., the HSC-Kinovea method) for measuring the flight time and height of vertical jumping using a low-cost high-speed Casio Exilim FH-25 camera (HSC). To this end, 25 subjects performed a total of 125 vertical jumps on an infrared (IR) platform while simultaneously being recorded with a HSC at 240 fps. Subsequently, 2 observers with no experience in video analysis analyzed the 125 videos independently using the open-license Kinovea 0.8.15 software. The flight times obtained were then converted into vertical jump heights, and the intraclass correlation coefficient (ICC), Bland-Altman plot, and Pearson correlation coefficient were calculated for those variables. The results showed a perfect correlation agreement (ICC = 1, p < 0.0001) between both observers' measurements of flight time and jump height and a highly reliable agreement (ICC = 0.997, p < 0.0001) between the observers' measurements of flight time and jump height using the HSC-Kinovea method and those obtained using the IR system, thus explaining 99.5% (p < 0.0001) of the differences (shared variance) obtained using the IR platform. As a result, besides requiring no previous experience in the use of this technology, the HSC-Kinovea method can be considered to provide similarly valid and reliable measurements of flight time and vertical jump height as more expensive equipment (i.e., IR). As such, coaches from many sports could use the HSC-Kinovea method to measure the flight time and height of their athlete's vertical jumps.

1998 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 2; High Lift

NASA Technical Reports Server (NTRS)

McMillin, S. Naomi (Editor)

1999-01-01

NASA's High-Speed Research Program sponsored the 1998 Aerodynamic Performance Technical Review on February 9-13, in Los Angeles, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, and Flight Controls. The review objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working HSCT aerodynamics. In particular, single- and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program.

A translational velocity command system for VTOL low speed flight

NASA Technical Reports Server (NTRS)

Merrick, V. K.

1982-01-01

A translational velocity flight controller, suitable for very low speed maneuvering, is described and its application to a large class of VTOL aircraft from jet lift to propeller driven types is analyzed. Estimates for the more critical lateral axis lead to the conclusion that the controller would provide a jet lift (high disk loading) VTOL aircraft with satisfactory "hands off" station keeping in operational conditions more stringent than any specified in current or projected requirements. It also seems likely that ducted fan or propeller driven (low disk loading) VTOL aircraft would have acceptable hovering handling qualities even in high turbulence, although in these conditions pilot intervention to maintain satisfactory station keeping would probably be required for landing in restricted areas.

First Deminsys (high speed FBG interrogator) flight

NASA Astrophysics Data System (ADS)

van Els, Thomas J.

2009-03-01

Deminsys is the world's fastest multi sensor / multi channel FBG interrogator, identifies one till four channels with typically 8 sensors per channel. The system is especially developed for the interrogation of signals up to 19,3 kHz for each sensor and the sample frequency is independent of the number of sensors. By having multiple sensors per fibre you can create a very compact network of sensors. Due to its revolutionary (light weight, compact and solid state) design, Deminsys seems to fit perfectly into (research) programs for aerospace, medic & life science, maritime, industrial, crash test and all other fast detection applications. Technobis Fibre Technologies (TFT) and NLR made a first test flight with the Deminsys optical fibre measurement system using the NLR test aircraft on October 24th 2008. This flight was a first step in the further development of the current system in order to make it suitable for operation on-board an aircraft and bring it from TRL3 towards TRL5, a functional model for aerospace applications.

1997 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 2; High Lift

NASA Technical Reports Server (NTRS)

Baize, Daniel G. (Editor)

1999-01-01

The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Aerodynamic Performance Workshop on February 25-28, 1997. The workshop was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of Configuration Aerodynamics (transonic and supersonic cruise drag, prediction and minimization), High-Lift, Flight Controls, Supersonic Laminar Flow Control, and Sonic Boom Prediction. The workshop objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientist and engineers working HSCT aerodynamics. In particular, single- and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT Motion Simulator results were presented along with executives summaries for all the Aerodynamic Performance technology areas.

Boeing B-29 Superfortress at the Lewis Flight Propulsion Laboratory

NASA Image and Video Library

1947-05-21

The NACA’s Lewis Flight Propulsion Laboratory used a Boeing B-29 Superfortress as a testbed for ramjet investigations in the late 1940s. NACA Lewis conducted a wide variety of studies on ramjets to determine basic operational data necessary to design missiles. This information included the relationship between combustion chamber and inlet pressure and temperature, velocity of the fuel-air ratio to the ignition characteristics, and combustion efficiency. Although wind tunnel and test stand studies were important first steps in determining these factors, actual flight tests were required. Lewis engineers modified the B-29 so that the ramjet could be stored in the bomb bay. Once the aircraft reached the desired altitude and speed the ramjet was suspended 52 inches below the bomb bay. The ramjet’s angle-of-attack could be independently adjusted, and a periscope permitted a view of the test article from inside the aircraft. Measurements were taken in free-stream conditions between 5,000 and 30,000 feet. The test flights, which began in April 1947, were flown at speeds up to Mach 0.51 and altitudes of 5,000 to 30,000 feet. The researchers first determined that 14,000 feet was the maximum altitude at which the engine could be ignited by spark. Flares were used to start the engine at altitudes up to 30,000 feet. Overall the ramjet operated well at all speeds and altitudes. Significant changes in fuel flow were successful at lower altitudes, but produced combustion blowout above 20,000 feet.

Exhaust emission calibration of two J-58 afterburning turbojet engines at simulated high-altitude, supersonic flight conditions

NASA Technical Reports Server (NTRS)

Holdeman, J. D.

1976-01-01

Emissions of total oxides of nitrogen, nitric oxide, unburned hydrocarbons, carbon monoxide, and carbon dioxide from two J-58 afterburning turbojet engines at simulated high-altitude flight conditions are reported. Test conditions included flight speeds from Mach 2 to 3 at altitudes from 16.0 to 23.5 km. For each flight condition exhaust measurements were made for four or five power levels, from maximum power without afterburning through maximum afterburning. The data show that exhaust emissions vary with flight speed, altitude, power level, and radial position across the exhaust. Oxides of nitrogen emissions decreased with increasing altitude and increased with increasing flight speed. Oxides of nitrogen emission indices with afterburning were less than half the value without afterburning. Carbon monoxide and hydrocarbon emissions increased with increasing altitude and decreased with increasing flight speed. Emissions of these species were substantially higher with afterburning than without.

MM-122: High speed civil transport

NASA Technical Reports Server (NTRS)

Demarest, Bill; Anders, Kurt; Manchec, John; Yang, Eric; Overgaard, Dan; Kalkwarf, Mike

1992-01-01

The rapidly expanding Pacific Rim market along with other growing markets indicates that the future market potential for a high speed civil transport is great indeed. The MM-122 is the answer to the international market desire for a state of the art, long range, high speed civil transport. It will carry 250 passengers a distance of 5200 nm at over twice the speed of sound. The MM-122 is designed to incorporate the latest technologies in the areas of control systems, propulsions, aerodynamics, and materials. The MM-122 will accomplish these goals using the following design parameters. First, a double delta wing planform with highly swept canards and an appropriately area ruled fuselage will be incorporated to accomplish desired aerodynamic characteristics. Propulsion will be provided by four low bypass variable cycle turbofan engines. A quad-redundant fly-by-wire flight control system will be incorporated to provide appropriate static stability and level 1 handling qualities. Finally, the latest in conventional metallic and modern composite materials will be used to provide desired weight and performance characteristics. The MM-122 incorporates the latest in technology and cost minimization techniques to provide a viable solution to this future market potential.

E-1152

NASA Image and Video Library

1954-01-17

These people and this equipment supported the flight of the NACA D-558-2 Skyrocket at the High-Speed Flight Station at South Base, Edwards AFB. Note the two Sabre chase planes, the P2B-1S launch aircraft, and the profusion of ground support equipment, including communications, tracking, maintenance, and rescue vehicles. Research pilot A. Scott Crossfield stands in front of the Skyrocket.

Mechanical power curve measured in the wake of pied flycatchers indicates modulation of parasite power across flight speeds.

PubMed

Johansson, L Christoffer; Maeda, Masateru; Henningsson, Per; Hedenström, Anders

2018-01-01

How aerodynamic power required for animal flight varies with flight speed determines optimal speeds during foraging and migratory flight. Despite its relevance, aerodynamic power provides an elusive quantity to measure directly in animal flight. Here, we determine the aerodynamic power from wake velocity fields, measured using tomographical particle image velocimetry, of pied flycatchers flying freely in a wind tunnel. We find a shallow U-shaped power curve, which is flatter than expected by theory. Based on how the birds vary body angle with speed, we speculate that the shallow curve results from increased body drag coefficient and body frontal area at lower flight speeds. Including modulation of body drag in the model results in a more reasonable fit with data than the traditional model. From the wake structure, we also find a single starting vortex generated from the two wings during the downstroke across flight speeds (1-9 m s -1 ). This is accomplished by the arm wings interacting at the beginning of the downstroke, generating a unified starting vortex above the body of the bird. We interpret this as a mechanism resulting in a rather uniform downwash and low induced power, which can help explain the higher aerodynamic performance in birds compared with bats. © 2018 The Author(s).

Flight test results of riblets at supersonic speeds

NASA Technical Reports Server (NTRS)

Zuniga, Fanny A.; Anderson, Bianca T.; Bertelrud, Arild

1992-01-01

A flight experiment to test and evaluate the skin friction drag characteristics of a riblet surface in turbulent flow at supersonic speeds was conducted at NASA Dryden. Riblets of groove sizes 0.0030 and 0.0013 in. were mounted on the F-104G flight test fixture. The test surfaces were surveyed with boundary layer rakes and pressure orifices to examine the boundary layer profiles and pressure distributions of the flow. Skin friction reductions caused by the riblet surface were reported based on measured differences of momentum thickness between the smooth and riblet surfaces obtained from the boundary layer data. Flight test results for the 0.0030 in. riblet show skin friction reductions of 4 to 8 % for Mach numbers ranging from 1.2 to 1.6 and Reynolds numbers ranging from 2 to 3.4 million per unit foot. The results from the 0.0013 in. riblets show skin friction reductions of 4 to 15 % for Mach 1.2 to 1.4 and Reynolds numbers ranging from 3.6 to 6 million per unit foot.

Analysis of the Na+/Ca2+ Exchanger Gene Family within the Phylum Nematoda

PubMed Central

He, Chao; O'Halloran, Damien M.

2014-01-01

Na+/Ca2+ exchangers are low affinity, high capacity transporters that rapidly transport calcium at the plasma membrane, mitochondrion, endoplasmic (and sarcoplasmic) reticulum, and the nucleus. Na+/Ca2+ exchangers are widely expressed in diverse cell types where they contribute homeostatic balance to calcium levels. In animals, Na+/Ca2+ exchangers are divided into three groups based upon stoichiometry: Na+/Ca2+ exchangers (NCX), Na+/Ca2+/K+ exchangers (NCKX), and Ca2+/Cation exchangers (CCX). In mammals there are three NCX genes, five NCKX genes and one CCX (NCLX) gene. The genome of the nematode Caenorhabditis elegans contains ten Na+/Ca2+ exchanger genes: three NCX; five CCX; and two NCKX genes. Here we set out to characterize structural and taxonomic specializations within the family of Na+/Ca2+ exchangers across the phylum Nematoda. In this analysis we identify Na+/Ca2+ exchanger genes from twelve species of nematodes and reconstruct their phylogenetic and evolutionary relationships. The most notable feature of the resulting phylogenies was the heterogeneous evolution observed within exchanger subtypes. Specifically, in the case of the CCX exchangers we did not detect members of this class in three Clade III nematodes. Within the Caenorhabditis and Pristionchus lineages we identify between three and five CCX representatives, whereas in other Clade V and also Clade IV nematode taxa we only observed a single CCX gene in each species, and in the Clade III nematode taxa that we sampled we identify NCX and NCKX encoding genes but no evidence of CCX representatives using our mining approach. We also provided re-annotation for predicted CCX gene structures from Heterorhabditis bacteriophora and Caenorhabditis japonica by RT-PCR and sequencing. Together, these findings reveal a complex picture of Na+/Ca2+ transporters in nematodes that suggest an incongruent evolutionary history of proteins that provide central control of calcium dynamics. PMID:25397810

Research on natural frequency based on modal test for high speed vehicles

NASA Astrophysics Data System (ADS)

Ma, Guangsong; He, Guanglin; Guo, Yachao

2018-04-01

High speed vehicle as a vibration system, resonance generated in flight may be harmful to high speed vehicles. It is possible to solve the resonance problem by acquiring the natural frequency of the high-speed aircraft and then taking some measures to avoid the natural frequency of the high speed vehicle. Therefore, In this paper, the modal test of the high speed vehicle was carried out by using the running hammer method and the PolyMAX modal parameter identification method. Firstly, the total frequency response function, coherence function of the high speed vehicle are obtained by the running hammer stimulation test, and through the modal assurance criterion (MAC) to determine the accuracy of the estimated parameters. Secondly, the first three order frequencies, the pole steady state diagram of the high speed vehicles is obtained by the PolyMAX modal parameter identification method. At last, the natural frequency of the vibration system was accurately obtained by the running hammer method.

Studies of the Speed Stability of a Tandem Helicopter in Forward Flight

NASA Technical Reports Server (NTRS)

Tapscott, Robert J; Amer, Kenneth B

1956-01-01

Flight-test measurements, related analytical studies, and corresponding pilots' opinions of the speed stability of tandem-rotor helicopter are presented. An undesirable instability, evidenced by rearward stick motion with increasing forward speed at constant power, is indicated to be caused by variations with speed of the front-rotor downwash at the rear rotor. An analytical expression for predicting changes in speed stability caused by changes in rotor geometry is derived and constants for use with the analytical expression are presented in chart form. Means for improving stability with speed are studied both analytically and experimentally. The test results also give some information as to the flow conditions at the rear rotor.

Research pilot John Griffith leaning out of the hatch on the X-1 #2

NASA Technical Reports Server (NTRS)

1950-01-01

In this photo, NACA research pilot John Griffith is leaning out the hatch of the X-1 #2. Surrounding him (left to right) are Dick Payne, Eddie Edwards, and maintenance chief Clyde Bailey. John Griffith became a research pilot at the National Advisory Committee for Aeronautics's Muroc Flight Test Unit in August of 1949, shortly before the NACA unit became the High-Speed Flight Research Station (now, NASA's Dryden Flight Research Center at Edwards, California). He flew the early experimental airplanes-the X-1, X-4, and D-558-1 and -2-flying the X-1 nine times, the X-4 three times, the D-558-1 fifteen times, and the D-558-2 nine times. He reached his top speed in the X-1 on 26 May 1950 when he achieved a speed of Mach 1.20. He was the first NACA pilot to fly the X-4. He left the NACA in 1950 to fly for Chance Vought in the F7U Cutlass. He then flew for United Airlines and for Westinghouse, where he became the Chief Engineering Test Pilot. He went on to work for the Federal Aviation Administration, assisting in the development of a supersonic transport before funding for that project ended. He then returned to United Airlines and worked as a flight instructor. John grew up in Homewood, Illinois, and attended Thornton Township Junior College in Harvey, Illinois, where he graduated as valedictorian in pre-engineering. He entered the Army Air Corps in November 1941, serving in the South Pacific during the Second World War that started soon after he joined. In 1942 and 1943 he flew 189 missions in the P-40 in New Guinea and was awarded two Distinguished Flying Crosses and four air medals. In October 1946, he left the service and studied aeronautical engineering at Purdue University, graduating with honors. He then joined the NACA at the Lewis Flight Propulsion Laboratory in Cleveland, Ohio (today's Glenn Research Center), where he participated in ramjet testing and icing research until moving to Muroc. Following his distinguished career, he retired to Penn Valley

Summary of Airfoil Data

NASA Technical Reports Server (NTRS)

Stivers, Louis S.; Abbott, Ira H.; von Doenhoff, Albert E.

1945-01-01

Recent airfoil data for both flight and wind-tunnel tests have been collected and correlated insofar as possible. The flight data consist largely of drag measurements made by the wake-survey method. Most of the data on airfoil section characteristics were obtained in the Langley two-dimensional low-turbulence pressure tunnel. Detail data necessary for the application of NACA 6-serles airfoils to wing design are presented in supplementary figures, together with recent data for the NACA 24-, 44-, and 230-series airfoils. The general methods used to derive the basic thickness forms for NACA 6- and 7-series airfoils and their corresponding pressure distributions are presented. Data and methods are given for rapidly obtaining the approximate pressure distributions for NACA four-digit, five-digit, 6-, and 7-series airfoils. The report includes an analysis of the lift, drag, pitching-moment, and critical-speed characteristics of the airfoils, together with a discussion of the effects of surface conditions. Available data on high-lift devices are presented. Problems associated with lateral-control devices, leading-edge air intakes, and interference are briefly discussed. The data indicate that the effects of surface condition on the lift and drag characteristics are at least as large as the effects of the airfoil shape and must be considered in airfoil selection and the prediction of wing characteristics. Airfoils permitting extensive laminar flow, such as the NACA 6-series airfoils, have much lower drag coefficients at high speed and cruising lift coefficients than earlier types-of airfoils if, and only if, the wing surfaces are sufficiently smooth and fair. The NACA 6-series airfoils also have favorable critical-speed characteristics and do not appear to present unusual problems associated with the application of high-lift and lateral-control devices. Much of the data given in the NACA Advance Confidential Report entitled "Preliminary Low-Drag-Airfoil and Flap Data from

A brief review of some mechanisms causing boundary layer transition at high speeds

NASA Technical Reports Server (NTRS)

Tauber, M. E.

1990-01-01

In high speed flight, the state of the boundary layer can strongly influence the design of vehicles through its effect on skin friction drag and aerodynamic heating. The major mechanisms causing boundary layer transition on high speed vehicles are briefly reviewed and some empirical relations from the unclassified literature are given for the transition Reynolds numbers.

Index of NACA Technical Publications, 1949 - May, 1951

NASA Technical Reports Server (NTRS)

1952-01-01

The Preface to the Index of NACA Technical Publications, 1915-1949, mentioned that regular supplements would be issued in the future. This is the first such Supplement and covers those documents issued through May of 1951. Similar arrangement is used in both Indexes. First, there is a classified listing of the subject categories; second, a chronological listing of NACA publications under each subject category; third, an alphabetical index to the subject categories; and finally, an author index. The latter feature was not included in the basic 1915-1949 Index but has been issued separately and is available upon request. Immediately following this Preface is an Explanatory Chart of NACA Publications Series Designations which may be of use in identifying references to NACA documents encountered in the literature.

Numerical investigation of flow on NACA4412 aerofoil with different aspect ratios

NASA Astrophysics Data System (ADS)

Demir, Hacımurat; Özden, Mustafa; Genç, Mustafa Serdar; Çağdaş, Mücahit

2016-03-01

In this study, the flow over NACA4412 was investigated both numerically and experimentally at a different Reynolds numbers. The experiments were carried out in a low speed wind tunnel with various angles of attack and different Reynolds numbers (25000 and 50000). Airfoil was manufactured using 3D printer with a various aspect ratios (AR = 1 and AR = 3). Smoke-wire and oil flow visualization methods were used to visualize the surface flow patterns. NACA4412 aerofoil was designed by using SOLIDWORKS. The structural grid of numerical model was constructed by ANSYS ICEM CFD meshing software. Furthermore, ANSYS FLUENT™ software was used to perform numerical calculations. The numerical results were compared with experimental results. Bubble formation was shown in CFD streamlines and smoke-wire experiments at z / c = 0.4. Furthermore, bubble shrunk at z / c = 0.2 by reason of the effects of tip vortices in both numerical and experimental studies. Consequently, it was seen that there was a good agreement between numerical and experimental results.

Some elementary aspects of non-linear airplane speed stability in constrained flight

NASA Astrophysics Data System (ADS)

Campos, L. M. B. C.; Fonseca, A. A.; Azinheira, J. R. C.

We review the longitudinal motion of an airplane, starting a dive at an arbitrary speed, and flown on a constant glide slope; this non-linear longitudinal speed stability problem is solved analytically (Section 2), to provide groundspeed as a function of time. Three restrictions were made: (i) neglect of the short period mode; (ii) low Mach number flight, i.e. omission of drag due to compressibility; (iii) small altitude change, so that the air density could be taken as constant. The predicted stability curves were compared with flight test data (Section 6), obtained using a CASA 212 Aviocar twin-turboprop transport. The flight data records showed that lateral motion was negligible; the effects of wind were compensated for, and the possible errors were estimated. An extension was made of the stability theory from still air (Section 2), to account for the presence of winds (Section 3); the latter were assumed not to exceed 30% of the groundspeed. The comparison of the theoretical stability curves with flight test data can be automated, as can the identification of the relevant data record. The disturbance intensity can be used as a parameter (Section 5) which indicates the start and end of flight manouever. This parameter is defined (Section 4) as the relative lift change, and for longitudinal flight it can be obtained from the wind velocity, vorticity components and changes of airspeed, angle-of-attack and vertical acceleration. It similarly has applications to perturbations of a horizontal turn.

F-100A on lakebed

NASA Technical Reports Server (NTRS)

1955-01-01

North American F-100A (52-5778) Super Sabre on the Rogers Dry Lakebed in a 1955 photograph. NACA High-Speed Flight Station, Edwards, California, flew this F-100 Super Sabre from 1954 to 1960 to investigate stability and control features of the then-new supersonic Air Force fighter. The program was part of NACA's support to the test and development program of the new 'century series' of aircraft -- F-100, F-101, F-102, F-104, F-105, F-106, and F-107.

Flying with the wind: Scale dependency of speed and direction measurements in modelling wind support in avian flight

USGS Publications Warehouse

Safi, Kamran; Kranstauber, Bart; Weinzierl, Rolf P.; Griffin, Larry; Reese, Eileen C.; Cabot, David; Cruz, Sebastian; Proaño, Carolina; Takekawa, John Y.; Newman, Scott H.; Waldenström, Jonas; Bengtsson, Daniel; Kays, Roland; Wikelski, Martin; Bohrer, Gil

2013-01-01

Background: Understanding how environmental conditions, especially wind, influence birds' flight speeds is a prerequisite for understanding many important aspects of bird flight, including optimal migration strategies, navigation, and compensation for wind drift. Recent developments in tracking technology and the increased availability of data on large-scale weather patterns have made it possible to use path annotation to link the location of animals to environmental conditions such as wind speed and direction. However, there are various measures available for describing not only wind conditions but also the bird's flight direction and ground speed, and it is unclear which is best for determining the amount of wind support (the length of the wind vector in a bird’s flight direction) and the influence of cross-winds (the length of the wind vector perpendicular to a bird’s direction) throughout a bird's journey.Results: We compared relationships between cross-wind, wind support and bird movements, using path annotation derived from two different global weather reanalysis datasets and three different measures of direction and speed calculation for 288 individuals of nine bird species. Wind was a strong predictor of bird ground speed, explaining 10-66% of the variance, depending on species. Models using data from different weather sources gave qualitatively similar results; however, determining flight direction and speed from successive locations, even at short (15 min intervals), was inferior to using instantaneous GPS-based measures of speed and direction. Use of successive location data significantly underestimated the birds' ground and airspeed, and also resulted in mistaken associations between cross-winds, wind support, and their interactive effects, in relation to the birds' onward flight.Conclusions: Wind has strong effects on bird flight, and combining GPS technology with path annotation of weather variables allows us to quantify these effects for

Radiation Transport and Shielding for Space Exploration and High Speed Flight Transportation

NASA Technical Reports Server (NTRS)

Maung, Khin Maung; Trapathi, R. K.

1997-01-01

Transportation of ions and neutrons in matter is of direct interest in several technologically important and scientific areas, including space radiation, cosmic ray propagation studies in galactic medium, nuclear power plants and radiological effects that impact industrial and public health. For the proper assessment of radiation exposure, both reliable transport codes and accurate data are needed. Nuclear cross section data is one of the essential inputs into the transport codes. In order to obtain an accurate parametrization of cross section data, theoretical input is indispensable especially for processes where there is little or no experimental data available. In this grant period work has been done on the studies of the use of relativistic equations and their one-body limits. The results will be useful in choosing appropriate effective one-body equation for reaction calculations. Work has also been done to improve upon the data base needed for the transport codes used in the studies of radiation transport and shielding for space exploration and high speed flight transportation. A phenomenological model was developed for the total absorption cross sections valid for any system of charged and/or uncharged collision pairs for the entire energy range. The success of the model is gratifying. It is being used by other federal agencies, national labs and universities. A list of publications based on the work during the grant period is given below and copies are enclosed with this report.

Flight paths of seabirds soaring over the ocean surface enable measurement of fine-scale wind speed and direction.

PubMed

Yonehara, Yoshinari; Goto, Yusuke; Yoda, Ken; Watanuki, Yutaka; Young, Lindsay C; Weimerskirch, Henri; Bost, Charles-André; Sato, Katsufumi

2016-08-09

Ocean surface winds are an essential factor in understanding the physical interactions between the atmosphere and the ocean. Surface winds measured by satellite scatterometers and buoys cover most of the global ocean; however, there are still spatial and temporal gaps and finer-scale variations of wind that may be overlooked, particularly in coastal areas. Here, we show that flight paths of soaring seabirds can be used to estimate fine-scale (every 5 min, ∼5 km) ocean surface winds. Fine-scale global positioning system (GPS) positional data revealed that soaring seabirds flew tortuously and ground speed fluctuated presumably due to tail winds and head winds. Taking advantage of the ground speed difference in relation to flight direction, we reliably estimated wind speed and direction experienced by the birds. These bird-based wind velocities were significantly correlated with wind velocities estimated by satellite-borne scatterometers. Furthermore, extensive travel distances and flight duration of the seabirds enabled a wide range of high-resolution wind observations, especially in coastal areas. Our study suggests that seabirds provide a platform from which to measure ocean surface winds, potentially complementing conventional wind measurements by covering spatial and temporal measurement gaps.

Flight paths of seabirds soaring over the ocean surface enable measurement of fine-scale wind speed and direction

PubMed Central

Yonehara, Yoshinari; Goto, Yusuke; Yoda, Ken; Watanuki, Yutaka; Young, Lindsay C.; Weimerskirch, Henri; Bost, Charles-André; Sato, Katsufumi

2016-01-01

Ocean surface winds are an essential factor in understanding the physical interactions between the atmosphere and the ocean. Surface winds measured by satellite scatterometers and buoys cover most of the global ocean; however, there are still spatial and temporal gaps and finer-scale variations of wind that may be overlooked, particularly in coastal areas. Here, we show that flight paths of soaring seabirds can be used to estimate fine-scale (every 5 min, ∼5 km) ocean surface winds. Fine-scale global positioning system (GPS) positional data revealed that soaring seabirds flew tortuously and ground speed fluctuated presumably due to tail winds and head winds. Taking advantage of the ground speed difference in relation to flight direction, we reliably estimated wind speed and direction experienced by the birds. These bird-based wind velocities were significantly correlated with wind velocities estimated by satellite-borne scatterometers. Furthermore, extensive travel distances and flight duration of the seabirds enabled a wide range of high-resolution wind observations, especially in coastal areas. Our study suggests that seabirds provide a platform from which to measure ocean surface winds, potentially complementing conventional wind measurements by covering spatial and temporal measurement gaps. PMID:27457932

Relation Between Spark-Ignition Engine Knock, Detonation Waves, and Autoignition as Shown by High-Speed Photography

NASA Technical Reports Server (NTRS)

Miller, Cearcy D

1946-01-01

A critical review of literature bearing on the autoignition and detonation-wave theories of spark-ignition engine knock and on the nature of gas vibrations associated with combustion and knock results in the conclusion that neither the autoignition theory nor the detonation-wave theory is an adequate explanation of spark-ignition engine knock. A knock theory is proposed, combining the autoignition and detonation-wave theories, which introduces the idea that the detonation wave develops in autoignited or after-burning gases, and ascribes comparatively low-pitched heavy knocks to autoignition but high-pitched pinging knocks to detonation waves with the possibility of combinations of the two types of knocks. Analysis of five shots of knocking combustion, taken with the NACA high-speed motion-picture camera at the rate of 40,000 photographs per second reveals propagation speeds ranging from 3250 to more than 5500 feet per second. The range of propagation speeds from 3250 to more than 5500 feet per second is held to be considered with the proposed combined theory but not with either the simple autoignition theory or the simple detonation-wave theory.

An Analysis of the Speed Commands from an Interval Management Algorithm during the ATD-1 Flight Test

NASA Technical Reports Server (NTRS)

Watters, Christine; Wilson, Sara R.; Swieringa, Kurt A.

2017-01-01

NASA's first Air Traffic Management Technology Demonstration (ATD-1) successfully completed a nineteen-day flight test under a NASA contract with Boeing, with Honeywell and United Airlines as sub-contractors. An Interval Management (IM) avionics prototype was built based on international IM standards, integrated into two test aircraft, and then flown in real-world conditions to determine if the goals of improving aircraft efficiency and airport throughput during high-density arrival operations could be met. This paper describes the speed behavior of the IM avionics prototype, focusing on the speed command rate and the number of speed increases.

Engine Propeller Research Building at the Lewis Flight Propulsion Laboratory

NASA Image and Video Library

1955-02-21

The Engine Propeller Research Building, referred to as the Prop House, emits steam from its acoustic silencers at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. In 1942 the Prop House became the first completed test facility at the new NACA laboratory in Cleveland, Ohio. It contained four test cells designed to study large reciprocating engines. After World War II, the facility was modified to study turbojet engines. Two of the test cells were divided into smaller test chambers, resulting in a total of six engine stands. During this period the NACA Lewis Materials and Thermodynamics Division used four of the test cells to investigate jet engines constructed with alloys and other high temperature materials. The researchers operated the engines at higher temperatures to study stress, fatigue, rupture, and thermal shock. The Compressor and Turbine Division utilized another test cell to study a NACA-designed compressor installed on a full-scale engine. This design sought to increase engine thrust by increasing its airflow capacity. The higher stage pressure ratio resulted in a reduction of the number of required compressor stages. The last test cell was used at the time by the Engine Research Division to study the effect of high inlet densities on a jet engine. Within a couple years of this photograph the Prop House was significantly altered again. By 1960 the facility was renamed the Electric Propulsion Research Building to better describe its new role in electric propulsion.

Aeronautics in NACA and NASA

NASA Technical Reports Server (NTRS)

1991-01-01

Initiated in 1915, the National Advisory Committee for Aeronautics/National Aeronautics and Space Administration (NACA/NASA) aeronautical programs have been the keystone of a sustained U.S. Government, industry, and university research effort which has been a primary factor in the development of our remarkable air transportation systems, the country's largest positive trade balance component, and the world's finest military Air Force. This overview summarizes the flow of events, and the major trends, that have led from the NACA origins to the present NASA Aeronautics program, and indicates some important directions for the years ahead.

F-100A with nose through hangar wall following Scott Crossfield's emergency landing

NASA Technical Reports Server (NTRS)

1954-01-01

A NACA High-Speed Flight Station hangar wall meets the nose of a North American F-100A Super Sabre airplane on 8 September 1954. On the first NACA research flight of airplane #52-5778, pilot Scott Crossfield had to make a powerless 'deadstick' landing following an engine fire warning. This was something North American's own test pilots doubted could be done, for the early F-100 lacked flaps and landed 'hot as hell.' Crossfield followed up the flawless approach and landing by coasting off the lakebed, up the ramp, and then through the front door of the NACA hangar, frantically trying to stop the F-100A, which had used up its emergency brake power. Crossfield missed the NACA X fleet, but crunched the nose of the aircraft through the hangar's side wall. It is reported that Chuck Yeager then proclaimed that while the sonic wall had been his, the hangar wall was Crossfield's! The hangar wall and the F-100A were repaired, and the airplane flew again.

1999 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 2; High Lift

NASA Technical Reports Server (NTRS)

Hahne, David E. (Editor)

1999-01-01

NASA's High-Speed Research Program sponsored the 1999 Aerodynamic Performance Technical Review on February 8-12, 1999 in Anaheim, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in the areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High Lift, and Flight Controls. The review objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among die scientists and engineers working on HSCT aerodynamics. In particular, single and midpoint optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented, along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program. This Volume 2/Part 2 publication covers the tools and methods development session.

Celebrating a Century of Flight

NASA Technical Reports Server (NTRS)

OKeefe, Sean O.; Jumper, John P.; Dailey, J. R.

2002-01-01

Since 1915, the National Advisory Committee for Aeronautics (NACA), transformed into NASA in 1958, has performed cutting-edge research to solve the problems of flight. Using a Grumman F4F-3 Wildcat during World War II, NACA engineers at the Langley Aeronautical Laboratory (now Langley Research Center) in Hampton, Virginia, used this aircraft to investigate the cuffs on the propeller blades to determine their efficiency. While not built to the full production standard of other Grumman Wildcats, research on this aircraft, the second F4F-3, proved most successful in advancing knowledge of the aerodynamics of this engine and propeller system. A close-up of the propeller blades with Curtiss Electric Propellers' logo is shown.

X-2 on ramp with B-50 mothership and support crew

NASA Technical Reports Server (NTRS)

1956-01-01

before it was lost Sept. 27, 1956. The pilot on Flight 17, Capt. Milburn Apt, had flown the aircraft to a record speed of Mach 3.2 (2,094 mph), thus becoming the first person to exceed Mach 3. During that last flight, inertial coupling occurred and the pilot was killed. The aircraft suffered little damage in the crash, resulting in proposals (never implemented) from the Langley Memorial Aeronautical Laboratory, Hampton, Virginia, to rebuild it for use in a hypersonic (Mach 5+) test program. In 1953, X-2 Number 2 was lost in an in-flight explosion while at the Bell Aircraft Company during captive flight trials and was jettisoned into Lake Ontario. The Air Force had previously flown the aircraft on three glide flights at Edwards Air Force Base, California, in 1952. Although the NACA's High-Speed Flight Station, Edwards, California, (predecessor of NASA's Dryden Flight Research Center) never actually flew the X-2 aircraft, the NACA did support the program primarily through Langley Memorial Aeronautical Laboratory wind-tunnel tests and Wallops Island, Virginia, rocket-model tests. The NACA High-Speed Flight Station also provided stability and control recording instrumentation and simulator support for the Air Force flights. In the latter regard, the NACA worked with the Air Force in using a special computer to extrapolate and predict aircraft behavior from flight data.

High-speed Imaging of Global Surface Temperature Distributions on Hypersonic Ballistic-Range Projectiles

NASA Technical Reports Server (NTRS)

Wilder, Michael C.; Reda, Daniel C.

2004-01-01

The NASA-Ames ballistic range provides a unique capability for aerothermodynamic testing of configurations in hypersonic, real-gas, free-flight environments. The facility can closely simulate conditions at any point along practically any trajectory of interest experienced by a spacecraft entering an atmosphere. Sub-scale models of blunt atmospheric entry vehicles are accelerated by a two-stage light-gas gun to speeds as high as 20 times the speed of sound to fly ballistic trajectories through an 24 m long vacuum-rated test section. The test-section pressure (effective altitude), the launch velocity of the model (flight Mach number), and the test-section working gas (planetary atmosphere) are independently variable. The model travels at hypersonic speeds through a quiescent test gas, creating a strong bow-shock wave and real-gas effects that closely match conditions achieved during actual atmospheric entry. The challenge with ballistic range experiments is to obtain quantitative surface measurements from a model traveling at hypersonic speeds. The models are relatively small (less than 3.8 cm in diameter), which limits the spatial resolution possible with surface mounted sensors. Furthermore, since the model is in flight, surface-mounted sensors require some form of on-board telemetry, which must survive the massive acceleration loads experienced during launch (up to 500,000 gravities). Finally, the model and any on-board instrumentation will be destroyed at the terminal wall of the range. For these reasons, optical measurement techniques are the most practical means of acquiring data. High-speed thermal imaging has been employed in the Ames ballistic range to measure global surface temperature distributions and to visualize the onset of transition to turbulent-flow on the forward regions of hypersonic blunt bodies. Both visible wavelength and infrared high-speed cameras are in use. The visible wavelength cameras are intensified CCD imagers capable of integration

High speed turboprop aeroacoustic study (counterrotation). Volume 1: Model development

NASA Technical Reports Server (NTRS)

Whitfield, C. E.; Mani, R.; Gliebe, P. R.

1990-01-01

The isolated counterrotating high speed turboprop noise prediction program was compared with model data taken in the GE Aircraft Engines Cell 41 anechoic facility, the Boeing Transonic Wind Tunnel, and in NASA-Lewis' 8x6 and 9x15 wind tunnels. The predictions show good agreement with measured data under both low and high speed simulated flight conditions. The installation effect model developed for single rotation, high speed turboprops was extended to include counterotation. The additional effect of mounting a pylon upstream of the forward rotor was included in the flow field modeling. A nontraditional mechanism concerning the acoustic radiation from a propeller at angle of attach was investigated. Predictions made using this approach show results that are in much closer agreement with measurement over a range of operating conditions than those obtained via traditional fluctuating force methods. The isolated rotors and installation effects models were combines into a single prediction program, results of which were compared with data taken during the flight test of the B727/UDF engine demonstrator aircraft. Satisfactory comparisons between prediction and measured data for the demonstrator airplane, together with the identification of a nontraditional radiation mechanism for propellers at angle of attack are achieved.

High speed turboprop aeroacoustic study (counterrotation). Volume 1: Model development

NASA Astrophysics Data System (ADS)

Whitfield, C. E.; Mani, R.; Gliebe, P. R.

1990-07-01

The isolated counterrotating high speed turboprop noise prediction program was compared with model data taken in the GE Aircraft Engines Cell 41 anechoic facility, the Boeing Transonic Wind Tunnel, and in NASA-Lewis' 8x6 and 9x15 wind tunnels. The predictions show good agreement with measured data under both low and high speed simulated flight conditions. The installation effect model developed for single rotation, high speed turboprops was extended to include counterotation. The additional effect of mounting a pylon upstream of the forward rotor was included in the flow field modeling. A nontraditional mechanism concerning the acoustic radiation from a propeller at angle of attach was investigated. Predictions made using this approach show results that are in much closer agreement with measurement over a range of operating conditions than those obtained via traditional fluctuating force methods. The isolated rotors and installation effects models were combines into a single prediction program, results of which were compared with data taken during the flight test of the B727/UDF engine demonstrator aircraft. Satisfactory comparisons between prediction and measured data for the demonstrator airplane, together with the identification of a nontraditional radiation mechanism for propellers at angle of attack are achieved.

Time-of-Flight Measurement of the Speed of Sound in Water

ERIC Educational Resources Information Center

Ganci, Salvatore

2016-01-01

A simple setup is designed to investigate a "time-of-flight" measurement of the speed of sound in water. This experiment only requires low cost components and is also very simple to understand by students. It could be easily used as a demonstration experiment.

Re-Computation of Numerical Results Contained in NACA Report No. 496

NASA Technical Reports Server (NTRS)

Perry, Boyd, III

2015-01-01

An extensive examination of NACA Report No. 496 (NACA 496), "General Theory of Aerodynamic Instability and the Mechanism of Flutter," by Theodore Theodorsen, is described. The examination included checking equations and solution methods and re-computing interim quantities and all numerical examples in NACA 496. The checks revealed that NACA 496 contains computational shortcuts (time- and effort-saving devices for engineers of the time) and clever artifices (employed in its solution methods), but, unfortunately, also contains numerous tripping points (aspects of NACA 496 that have the potential to cause confusion) and some errors. The re-computations were performed employing the methods and procedures described in NACA 496, but using modern computational tools. With some exceptions, the magnitudes and trends of the original results were in fair-to-very-good agreement with the re-computed results. The exceptions included what are speculated to be computational errors in the original in some instances and transcription errors in the original in others. Independent flutter calculations were performed and, in all cases, including those where the original and re-computed results differed significantly, were in excellent agreement with the re-computed results. Appendix A contains NACA 496; Appendix B contains a Matlab(Reistered) program that performs the re-computation of results; Appendix C presents three alternate solution methods, with examples, for the two-degree-of-freedom solution method of NACA 496; Appendix D contains the three-degree-of-freedom solution method (outlined in NACA 496 but never implemented), with examples.

X-2 on Transportation Dolly

NASA Technical Reports Server (NTRS)

1952-01-01

, and made a total of 17 (4 glide and 13 powered) flights before it was lost Sept. 27, 1956. The pilot on Flight 17, Capt. Milburn Apt, had flown the aircraft to a record speed of Mach 3.2 (2,094 mph), thus becoming the first person to exceed Mach 3. During that last flight, inertial coupling occurred and the pilot was killed. The aircraft suffered little damage in the crash, resulting in proposals (never implemented) from the Langley Memorial Aeronautical Laboratory, Hampton, Virginia, to rebuild it for use in a hypersonic (Mach 5+) test program. In 1953, X-2 Number 2 was lost in an in-flight explosion while at the Bell Aircraft Company during captive flight trials and was jettisoned into Lake Ontario. The Air Force had previously flown the aircraft on three glide flights at Edwards Air Force Base, California, in 1952. Although the NACA's High-Speed Flight Station, Edwards, California, (predecessor of NASA's Dryden Flight Research Center) never actually flew the X-2 aircraft, the NACA did support the program primarily through Langley Memorial Aeronautical Laboratory wind-tunnel tests and Wallops Island, Virginia, rocket-model tests. The NACA High-Speed Flight Station also provided stability-and-control recording instrumentation and simulator support for the Air Force flights. In the latter regard, the NACA worked with the Air Force in using a special computer to extrapolate and predict aircraft behavior from flight data.

X-36 Tailless Fighter Agility Research Aircraft on lakebed during high-speed taxi tests

NASA Technical Reports Server (NTRS)

1996-01-01

The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. More taxi and radio frequency tests were slated before it's first flight would be made. This took place on May 17, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems

Cryogenic, high speed, turbopump bearing cooling requirements

NASA Technical Reports Server (NTRS)

Dolan, Fred J.; Gibson, Howard G.; Cannon, James L.; Cody, Joe C.

1988-01-01

Although the Space Shuttle Main Engine (SSME) has repeatedly demonstrated the capability to perform during launch, the High Pressure Oxidizer Turbopump (HPOTP) main shaft bearings have not met their 7.5 hour life requirement. A tester is being employed to provide the capability of subjecting full scale bearings and seals to speeds, loads, propellants, temperatures, and pressures which simulate engine operating conditions. The tester design permits much more elaborate instrumentation and diagnostics than could be accommodated in an SSME turbopump. Tests were made to demonstrate the facilities; and the devices' capabilities, to verify the instruments in its operating environment and to establish a performance baseline for the flight type SSME HPOTP Turbine Bearing design. Bearing performance data from tests are being utilized to generate: (1) a high speed, cryogenic turbopump bearing computer mechanical model, and (2) a much improved, very detailed thermal model to better understand bearing internal operating conditions. Parametric tests were also made to determine the effects of speed, axial loads, coolant flow rate, and surface finish degradation on bearing performance.

A second-generation high speed civil transport: Stingray

NASA Technical Reports Server (NTRS)

Engdahl, Sean; Lopes, Kevin; Ngan, Angelen; Perrin, Joseph; Phipps, Marcus; Westman, Blake; Yeo, Urn

1992-01-01

The Stingray is the second-generation High Speed Civil Transport (HSCT) designed for the 21st Century. This aircraft is designed to be economically viable and environmentally sound transportation competitive in markets currently dominated by subsonic aircraft such as the Boeing 747 and upcoming McDonnell Douglas MD-12. With the Stringray coming into service in 2005, a ticket price of 21 percent over current subsonic airlines will cover operational costs with a 10 percent return on investment. The cost per aircraft will be $202 million with the Direct Operating Cost equal to $0.072 per mile per seat. This aircraft has been designed to be a realistic aircraft that can be built within the next ten to fifteen years. There was only one main technological improvement factor used in the design, that being for the engine specific fuel consumption. The Stingray, therefore, does not rely on technology that does not exist. The Stingray will be powered by four mixed flow turbofans that meet both nitrous oxide emissions and FAR 36 Stage 3 noise regulations. It will carry 250 passengers a distance of 5200 nautical miles at a speed of Mach 2.4. The shape of the Stingray, while optimized for supersonic flight, is compatible with all current airline facilities in airports around the world. As the demand for economical, high-speed flight increases, the Stingray will be ready and able to meet those demands.

High-speed civil transport - Advanced flight deck challenges

NASA Technical Reports Server (NTRS)

Swink, Jay R.; Goins, Richard T.

1992-01-01

This paper presents the results of a nine month study of the HSCT flight deck challenges and assessment of its benefits. Operational requirements are discussed and the most significant findings for specified advanced concepts are highlighted. These concepts are a no nose-droop configuration, a far forward cockpit location and advanced crew monitoring and control of complex systems. Results indicate that the no nose-droop configuration is critically dependent on the design and development of a safe, reliable and certifiable synthetic vision system (SVS). This configuration would cause significant weight, performance and cost penalties. A far forward cockpit configuration with a tandem seating arrangement allows either an increase in additional payload or potential downsizing of the vehicle leading to increased performance efficiency and reductions in emissions. The technologies enabling such capabilities, which provide for Category III all-weather opreations on every flight represent a benefit multiplier in a 20005 ATM network in terms of enhanced economic viability and environmental acceptability.

Analysis of In-Flight Structural Failures of P-3C Wing Leading Edge Segments

DTIC Science & Technology

1992-06-01

with published empirical data for tangential velocity and/or pressure coefficient distributions for the NACA 0012 and Eppler E64 airfoils before its use...tangential velocity distribution for the Eppler airfoil . No difference from the NACA 0012 Cp data could be identified. 5. Flight Regime Selection It was...37 1. P-3 Airfoil Section ...... ............ .. 37 2. Program Inputs and Outputs .. ........ .. 37 3. Program Operation

Practical Possibilities of High-Altitude Flight with Exhaust-Gas Turbines in Connection with Spark Ignition Engines Comparative Thermodynamic and Flight Mechanical Investigations

NASA Technical Reports Server (NTRS)

Weise, A.

1947-01-01

As a means of preparing for high-altitude flight with spark-ignition engines in conjunction with exhaust-gas turbosuperchargers, various methods of modifying the exhaust-gas temperatures, which are initially higher than a turbine can withstand are mathematically compared. The thermodynamic results first obtained are then examined with respect to the effect on flight speed, climbing speed, ceiling, economy, and cruising range. The results are so presented in a generalized form that they may be applied to every appropriate type of aircraft design and a comparison with the supercharged engine without exhaust-gas turbine can be made.

X-36 Tailless Fighter Agility Research Aircraft on lakebed during high-speed taxi tests

NASA Technical Reports Server (NTRS)

1996-01-01

The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X

Index of Naca Technical Publications, June 1953 - May 1954

NASA Technical Reports Server (NTRS)

1954-01-01

The Preface to the Index of NACA Technical Publications, 1915 - 1949, mentioned that regular supplements would be issued in the future. This is the third such Supplement and covers those documents issued from June 1953 through May 1954. Also included are certain documents dated prior to June 1953 which have been declassified during the period covered by this supplement. Similar arrangement is used in these Indexes. First, there is a classified listing of the subject categories; second, a chronological listing of NACA publications under each subject category; third, an alphabetical index to the subject categories; and finally, an author index. Immediately following this Preface is an Explanatory Chart of NACA Publications Series Designations which may be of use in identifying references to NACA research reports encountered in the literature.

Pressure distribution over an NACA 23012 airfoil with an NACA 23012 external-airfoil flap

NASA Technical Reports Server (NTRS)

Wenzinger, Carl J

1938-01-01

Report presents the results of pressure-distribution tests of an NACA 23012 airfoil with an NACA 23012 external airfoil flap made in the 7 by 10-foot wind tunnel. The pressures were measured on the upper and lower surfaces at one chord section on both the main airfoil and on the flap for several different flap deflections and at several angles of attack. A test installation was used in which the airfoil was mounted horizontally in the wind tunnel between vertical end planes so that two-dimensional flow was approximated. The data are presented in the form of pressure-distribution diagrams and as graphs of calculated coefficients for the airfoil-and-flap combination and for the flap alone.

Simulations of High Speed Fragment Trajectories

NASA Astrophysics Data System (ADS)

Yeh, Peter; Attaway, Stephen; Arunajatesan, Srinivasan; Fisher, Travis

2017-11-01

Flying shrapnel from an explosion are capable of traveling at supersonic speeds and distances much farther than expected due to aerodynamic interactions. Predicting the trajectories and stable tumbling modes of arbitrary shaped fragments is a fundamental problem applicable to range safety calculations, damage assessment, and military technology. Traditional approaches rely on characterizing fragment flight using a single drag coefficient, which may be inaccurate for fragments with large aspect ratios. In our work we develop a procedure to simulate trajectories of arbitrary shaped fragments with higher fidelity using high performance computing. We employ a two-step approach in which the force and moment coefficients are first computed as a function of orientation using compressible computational fluid dynamics. The force and moment data are then input into a six-degree-of-freedom rigid body dynamics solver to integrate trajectories in time. Results of these high fidelity simulations allow us to further understand the flight dynamics and tumbling modes of a single fragment. Furthermore, we use these results to determine the validity and uncertainty of inexpensive methods such as the single drag coefficient model.

OPTIMIZATION OF HIGH-SPEED GC/TOFMS FOR METHOD TO-14 ANALYSIS

EPA Science Inventory

A fast GC/MS system (FGCMS) consisting of a high-speed gas chromatograph equipped with a narrow bandwidth injection accessory and a time-of-flight mass spectrometer detector is being optimized for analysis of Method TO-14 target compounds. The system consists entirely of comm...

1999 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 2; High Lift

NASA Technical Reports Server (NTRS)

Hahne, David E. (Editor)

1999-01-01

The High-Speed Research Program sponsored the NASA High-Speed Research Program Aerodynamic Performance Review on February 8-12, 1999 in Anaheim, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of: Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization) and High-Lift. The review objectives were to: (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientist and engineers working HSCT aerodynamics. The HSR AP Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas within the airframe element of the HSR Program. This Volume 2/Part 1 publication presents the High-Lift Configuration Development session.

Index of NACA Technical Publications: June, 1955 - June, 1956

NASA Technical Reports Server (NTRS)

1956-01-01

This Index of NACA Technical Publications covers those NACA research reports issued in the period of June 1955 through June 1956. It is the fifth supplement to the basic 1919-1949 Index. The res ear c h reports issued prior to June 1955 which have been declassified since that date have also been included. In addition, current announcement of newly declassified materials is regularly made in the NACA Research Abstracts and Reclassification Notice. The arrangement of the present Index follows that of its predecessors: (1) A listing of the subject categories by numerical classifications, (2) a chronological listing of the NACA research reports under each subject category, (3) an aIphabe ic a I index to the subject categories, and (4) an author index. An Explanatory Chart on page iii may be helpful in identifying references to NACA research reports encountered in the literature. Entries included herein duplicate in part the information of the index cards furnished with the individual research reports. Recipients maintaining card fiIes may wish to discard those index cards on hand for unclassified research reports issued during the June 1955-June 1956 period. Newly available research reports are currently announced in the NACA Research Abstracts and Reclassification Notice and are normally available for a period of five years after announcement. Most of the older research reports (those issued prior to May 1951) are thus available on a "loan only" basis within the United States

Determination of Boundary-Layer Transition on Three Symmetrical Airfoils in the NACA Full-Scale Wind Tunnel

NASA Technical Reports Server (NTRS)

Silverstein, Abe; Becker, John V

1938-01-01

For the purpose of studying the transition from laminar to turbulent flow, boundary-layer measurements were made in the NACA full-scale wind tunnel on three symmetrical airfoils of NACA 0009, 0012, and 0018 sections. The effects of variations in lift coefficient, Reynolds number, and airfoil thickness on transition were investigated. Air speed in the boundary layer was measured by total-head tubes and by hot wires; a comparison of transition as indicated by the two techniques was obtained. The results indicate no unique value of Reynolds number for the transition, whether the Reynolds number is based upon the distance along the chord or upon the thickness of the boundary layer at the transition point. In general, the transition is not abrupt and occurs in a region that varies in length as a function of the test conditions.

Flight-Path Characteristics for Decelerating From Supercircular Speed

NASA Technical Reports Server (NTRS)

Luidens, Roger W.

1961-01-01

Characteristics of the following six flight paths for decelerating from a supercircular speed are developed in closed form: constant angle of attack, constant net acceleration, constant altitude" constant free-stream Reynolds number, and "modulated roll." The vehicles were required to remain in or near the atmosphere, and to stay within the aerodynamic capabilities of a vehicle with a maximum lift-drag ratio of 1.0 and within a maximum net acceleration G of 10 g's. The local Reynolds number for all the flight paths for a vehicle with a gross weight of 10,000 pounds and a 600 swept wing was found to be about 0.7 x 10(exp 6). With the assumption of a laminar boundary layer, the heating of the vehicle is studied as a function of type of flight path, initial G load, and initial velocity. The following heating parameters were considered: the distribution of the heating rate over the vehicle, the distribution of the heat per square foot over the vehicle, and the total heat input to the vehicle. The constant G load path at limiting G was found to give the lowest total heat input for a given initial velocity. For a vehicle with a maximum lift-drag ratio of 1.0 and a flight path with a maximum G of 10 g's, entry velocities of twice circular appear thermo- dynamically feasible, and entries at velocities of 2.8 times circular are aerodynamically possible. The predominant heating (about 85 percent) occurs at the leading edge of the vehicle. The total ablated weight for a 10,000-pound-gross-weight vehicle decelerating from an initial velocity of twice circular velocity is estimated to be 5 percent of gross weight. Modifying the constant G load flight path by a constant-angle-of-attack segment through a flight- to circular-velocity ratio of 1.0 gives essentially a "point landing" capability but also results in an increased total heat input to the vehicle.

Foraging at the edge of the world: low-altitude, high-speed manoeuvering in barn swallows

PubMed Central

Warrick, Douglas R.; Hedrick, Tyson L.; Crandell, Kristen E.

2016-01-01

While prior studies of swallow manoeuvering have focused on slow-speed flight and obstacle avoidance in still air, swallows survive by foraging at high speeds in windy environments. Recent advances in field-portable, high-speed video systems, coupled with precise anemometry, permit measures of high-speed aerial performance of birds in a natural state. We undertook the present study to test: (i) the manner in which barn swallows (Hirundo rustica) may exploit wind dynamics and ground effect while foraging and (ii) the relative importance of flapping versus gliding for accomplishing high-speed manoeuvers. Using multi-camera videography synchronized with wind-velocity measurements, we tracked coursing manoeuvers in pursuit of prey. Wind speed averaged 1.3–2.0 m s−1 across the atmospheric boundary layer, exhibiting a shear gradient greater than expected, with instantaneous speeds of 0.02–6.1 m s−1. While barn swallows tended to flap throughout turns, they exhibited reduced wingbeat frequency, relying on glides and partial bounds during maximal manoeuvers. Further, the birds capitalized on the near-earth wind speed gradient to gain kinetic and potential energy during both flapping and gliding turns; providing evidence that such behaviour is not limited to large, fixed-wing soaring seabirds and that exploitation of wind gradients by small aerial insectivores may be a significant aspect of their aeroecology. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight'. PMID:27528781

E-2578

NASA Image and Video Library

1956-09-27

NACA High-Speed Flight Station test pilot Stan Butchart flying the Iron Cross, the mechanical reaction control simulator. High-pressure nitrogen gas expanded selectively, by the pilot, through the small reaction control thrusters maneuvered the Iron Cross through the three axes. The exhaust plume can be seen from the aft thruster. The tanks containing the gas can be seen on the cart at the base of the pivot point of the Iron Cross. NACA technicians built the iron-frame simulator, which matched the inertia ratios of the Bell X-1B airplane, installing six jet nozzles to control the movement about the three axes of pitch, roll, and yaw.

E-960

NASA Image and Video Library

1953-04-27

In the center foreground of this 1953 hanger photo is the YF-84A (NACA 134/Air Force 45-59490) used for vortex generator research. It arrived on November 28, 1949, and departed on April 21, 1954. Beside it is the third D-558-1 aircraft (NACA 142/Navy 37972). This aircraft was used for a total of 78 transonic research flights from April 1949 to June 1954. It replaced the second D-558-1, lost in the crash which killed Howard Lilly. Just visible on the left edge is the nose of the first D-558-2 (NACA 143/Navy 37973). Douglas turned the aircraft over to NACA on August 31, 1951, after the contractor had completed its initial test flights. NACA only made a single flight with the aircraft, on September 17, 1956, before the program was cancelled. In the center of the photo is the B-47A (NACA 150/Air Force 49-1900). The B-47 jet bomber, with its thin, swept-back wings, and six podded engines, represented the state of the art in aircraft design in the early 1950s. The aircraft undertook a number of research activities between May 1953 and its 78th and final research flight on November 22, 1957. The tests showed that the aircraft had a buffeting problem at speeds above Mach 0.8. Among the pilots who flew the B-47 were later X-15 pilots Joe Walker, A. Scott Crossfield, John B. McKay, and Neil A. Armstrong. On the right side of the B-47 is NACA's X-1 (Air Force 46-063). The second XS-1 aircraft built, it was fitted with a thicker wing than that on the first aircraft, which had exceeded Mach 1 on October 14, 1947. Flight research by NACA pilots indicated that this thicker wing produced 30 percent more drag at transonic speeds compared to the thinner wing on the first X-1. After a final flight on October 23, 1951, the aircraft was grounded due to the possibility of fatigue failure of the nitrogen spheres used to pressurize the fuel tanks. At the time of this photo, in 1953, the aircraft was in storage. In 1955, the aircraft was extensively modified, becoming the X-1E. In front o

Large-scale Advanced Prop-fan (LAP) high speed wind tunnel test report

NASA Technical Reports Server (NTRS)

Campbell, William A.; Wainauski, Harold S.; Arseneaux, Peter J.

1988-01-01

High Speed Wind Tunnel testing of the SR-7L Large Scale Advanced Prop-Fan (LAP) is reported. The LAP is a 2.74 meter (9.0 ft) diameter, 8-bladed tractor type rated for 4475 KW (6000 SHP) at 1698 rpm. It was designated and built by Hamilton Standard under contract to the NASA Lewis Research Center. The LAP employs thin swept blades to provide efficient propulsion at flight speeds up to Mach .85. Testing was conducted in the ONERA S1-MA Atmospheric Wind Tunnel in Modane, France. The test objectives were to confirm that the LAP is free from high speed classical flutter, determine the structural and aerodynamic response to angular inflow, measure blade surface pressures (static and dynamic) and evaluate the aerodynamic performance at various blade angles, rotational speeds and Mach numbers. The measured structural and aerodynamic performance of the LAP correlated well with analytical predictions thereby providing confidence in the computer prediction codes used for the design. There were no signs of classical flutter throughout all phases of the test up to and including the 0.84 maximum Mach number achieved. Steady and unsteady blade surface pressures were successfully measured for a wide range of Mach numbers, inflow angles, rotational speeds and blade angles. No barriers were discovered that would prevent proceeding with the PTA (Prop-Fan Test Assessment) Flight Test Program scheduled for early 1987.

Design and flight test results of high speed optical bidirectional link between stratospheric platforms for aerospace applications

NASA Astrophysics Data System (ADS)

Briatore, S.; Akhtyamov, R.; Golkar, A.

2017-08-01

As small and nanosatellites become increasingly relevant in the aerospace industry1, 2, the need of efficient, lightweight and cost-effective networking solutions drives the need for the development of lightweight and low cost networking and communication terminals. In this paper we propose the design and prototype results of a hybrid optical and radio communication architecture developed to fit the coarse pointing capabilities of nanosatellites, tested through a proxy flight experiment on stratospheric balloons. This system takes advantage of the higher data-rate offered by optical communication channels while relying on the more mature and stable technology of conventional radio systems for link negotiation and low-speed data exchange. Such architecture allows the user to overcome the licensing requirements and scarce availability of high data-rate radio frequency channels in the commonly used bands. Outlined are the architecture, development and test of the mentioned terminal, with focus on the communication part and supporting technologies, including the navigation algorithm, the developed fail-safe approach, and the evolution of the pointing system continuing previous work done in 3. The system has been built with commercial-off-the-shelf components and demonstrated on a stratospheric balloon launch campaign. The paper outlines the results of an in-flight demonstration, where the two platforms successfully established an optical link at stratospheric altitudes. The results are then analyzed and contextualized in plans of future work for nanosatellite implementations.

NACA Apprentice is Trained on the Lab's Altitude Systems

NASA Image and Video Library

1955-02-21

An apprentice at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory shown training on the altitude supply air systems in the Engine Research Building. An ongoing four-year apprentice program was established at the laboratory in 1949 to facilitate the close interaction of the lab’s engineers, mechanics, technicians, and scientists. The apprentice school covered a variety of trades including aircraft mechanic, electronics instrumentation, machinist, and altitude systems mechanic, seen in this photograph. The apprentices rotated through the various shops and facilities to provide them with a well-rounded understanding of the work at the lab. The specialized skills required meant that NACA apprentices were held to a higher standard than those in industry. They had to pass written civil service exams before entering the program. Previous experience with mechanical model airplanes, radio transmission, six months of work experience, or one year of trade school was required. The Lewis program was certified by both the Department of Labor and the State of Ohio. One hundred fifty of the 2,000 hours of annual training were spent in the classroom. The remainder was devoted to study of models and hands-on work in the facilities. Examinations were coupled with evaluation by supervisors in the shops. The apprentices were promoted through a series of grades until they reached journeyman status. Those who excelled in the Apprentice Program would be considered for a separate five-year engineering draftsman program.

Characteristics and Drivers of High-Altitude Ladybird Flight: Insights from Vertical-Looking Entomological Radar

PubMed Central

Jeffries, Daniel L.; Chapman, Jason; Roy, Helen E.; Humphries, Stuart; Harrington, Richard; Brown, Peter M. J.; Handley, Lori-J. Lawson

2013-01-01

Understanding the characteristics and drivers of dispersal is crucial for predicting population dynamics, particularly in range-shifting species. Studying long-distance dispersal in insects is challenging, but recent advances in entomological radar offer unique insights. We analysed 10 years of radar data collected at Rothamsted Research, U.K., to investigate characteristics (altitude, speed, seasonal and annual trends) and drivers (aphid abundance, air temperature, wind speed and rainfall) of high-altitude flight of the two most abundant U.K. ladybird species (native Coccinella septempunctata and invasive Harmonia axyridis). These species cannot be distinguished in the radar data since their reflectivity signals overlap, and they were therefore analysed together. However, their signals do not overlap with other, abundant insects so we are confident they constitute the overwhelming majority of the analysed data. The target species were detected up to ∼1100 m above ground level, where displacement speeds of up to ∼60 km/h were recorded, however most ladybirds were found between ∼150 and 500 m, and had a mean displacement of 30 km/h. Average flight time was estimated, using tethered flight experiments, to be 36.5 minutes, but flights of up to two hours were observed. Ladybirds are therefore potentially able to travel 18 km in a “typical” high-altitude flight, but up to 120 km if flying at higher altitudes, indicating a high capacity for long-distance dispersal. There were strong seasonal trends in ladybird abundance, with peaks corresponding to the highest temperatures of mid-summer, and warm air temperature was the key driver of ladybird flight. Climatic warming may therefore increase the potential for long-distance dispersal in these species. Low aphid abundance was a second significant factor, highlighting the important role of aphid population dynamics in ladybird dispersal. This research illustrates the utility of radar for studying high

Walter C. Williams with Brig. General Albert Boyd

NASA Technical Reports Server (NTRS)

1950-01-01

Walter C. Williams, (behind airplane model) Head of the National Advisory Committee for Aeronautics High-Speed Flight Research Station at Edwards Air Force Base in California is examining a Northrop X-4 research airplane with Brig. Gen. Albert Boyd, Commander of Edwards Air Force Base. At Edwards, the Air Force Air Material Command ran a brief program on the X-4 during the summer of 1950 before delivering it to the NACA. Data was collected on these 14 flights, so they were logged as NACA test flights. General Boyd made flight number 13. Air Force and NACA pilots completed a total of 82 flights on X-4 #2 (46-677) between August 1950 and September 1953. There are three things that made the Mojave Desert, where Edwards Air Force Base is located, so well suited for flight research. The first was the area's flying conditions--clear skies with great visibility almost every day of the year. The second was the 44-square-mile Rogers Dry Lake, a natural landing site that General Boyd referred to as 'God's gift to the Air Force.' The third was the unpopulated area surrounding the lakebed, which led to fewer complaints about aircraft noise (including sonic booms) than would have occurred in more populated areas. There was also less chance of injury to the surrounding population in the event of an aircraft accident.

The Next Generation of High-Speed Dynamic Stability Wind Tunnel Testing (Invited)

NASA Technical Reports Server (NTRS)

Tomek, Deborah M.; Sewall, William G.; Mason, Stan E.; Szchur, Bill W. A.

2006-01-01

Throughout industry, accurate measurement and modeling of dynamic derivative data at high-speed conditions has been an ongoing challenge. The expansion of flight envelopes and non-conventional vehicle design has greatly increased the demand for accurate prediction and modeling of vehicle dynamic behavior. With these issues in mind, NASA Langley Research Center (LaRC) embarked on the development and shakedown of a high-speed dynamic stability test technique that addresses the longstanding problem of accurately measuring dynamic derivatives outside the low-speed regime. The new test technique was built upon legacy technology, replacing an antiquated forced oscillation system, and greatly expanding the capabilities beyond classic forced oscillation testing at both low and high speeds. The modern system is capable of providing a snapshot of dynamic behavior over a periodic cycle for varying frequencies, not just a damping derivative term at a single frequency.

Aeromechanics of a High Speed Coaxial Helicopter Rotor

NASA Astrophysics Data System (ADS)

Schmaus, Joseph Henry

The current work seeks to understand the aeromechanics of lift offset coaxial rotors in high speeds. Future rotorcraft will need to travel significantly faster that modern rotorcraft do while maintaining hovering efficiency and low speed maneuverability. The lift offset coaxial rotor has been shown to have those capabilities. A majority of existing coaxial research is focused on hovering performance, and few studies examine the forward flight performance of a coaxial rotor with lift offset. There are even fewer studies of a single rotor with lift offset. The current study used comprehensive analysis and a new set of wind tunnel experiments to explore the aeromechanics of a lift offset coaxial rotor in high speed forward flight. The simulation was expanded from UMARC to simultaneously solve multiple rotors with coupled aerodynamics. It also had several modifications to improve the aerodynamics of the near-wake model in reverse flow and improve the modeling of blade passages. Existing coaxial hovering tests and flight test data from the XH-59A were used to validate the steady performance and blade loads of the comprehensive analysis. It was used to design the structural layout of the blades used in the wind tunnel experiment as well as the test envelope and testing procedure. The wind tunnel test of a model rotor developed by the University of Texas at Austin and the University of Maryland was performed in the Glenn L Martin Wind Tunnel. The test envelope included advance ratios 0.21-0.53, collectives 4°- 8°, and lift offsets 0%-20% for both rotors tested in isolation and as a coaxial system operating at 900 RPM. Rotating frame hub loads, pushrod loads, and pitch angle were recorded independently for each rotor. Additional studies were performed at 1200 RPM to isolate Reynold effects and with varying rotor-to-rotor phase to help quantify aerodynamic interactions. Lift offset fundamentally changes the lift distribution around the rotor disk, doing so increases the

F-100A on lakebed

NASA Technical Reports Server (NTRS)

1955-01-01

North American F-100A (52-5778) Super Sabre is parked on the Rogers Dry Lakebed at Edwards Air Force Base, California, 1955. This photo shows the large tail on the F-100A. When the basic research was completed on this F-100A another program was assigned. On March 5, 1957 two aeronautical engineers and a test pilot from NACA High-Speed Flight Station took the airplane to participate in a Gunnery Operations program at Nellis Air Force Base, Nevada. When the program was completed the aircraft returned for other assignments to NACA, at Edwards, California.

The high speed interconnect system architecture and operation

NASA Astrophysics Data System (ADS)

Anderson, Steven C.

The design and operation of a fiber-optic high-speed interconnect system (HSIS) being developed to meet the requirements of future avionics and flight-control hardware with distributed-system architectures are discussed. The HSIS is intended for 100-Mb/s operation of a local-area network with up to 256 stations. It comprises a bus transmission system (passive star couplers and linear media linked by active elements) and network interface units (NIUs). Each NIU is designed to perform the physical, data link, network, and transport functions defined by the ISO OSI Basic Reference Model (1982 and 1983) and incorporates a fiber-optic transceiver, a high-speed protocol based on the SAE AE-9B linear token-passing data bus (1986), and a specialized application interface unit. The operating modes and capabilities of HSIS are described in detail and illustrated with diagrams.

The Effect of Surface Irregularities on Wing Drag. 3; Roughness

NASA Technical Reports Server (NTRS)

Hood, Manley J.

1938-01-01

Tests have been made in the N.A.C.A. 8-foot high-speed wind tunnel of the drag caused by roughness on the surface of an airfoil of N.A.C.A. 23012 section and 5-foot chord. The tests were made at speeds from 80 t o 500 miles per hour at lift coefficients from 0 to 0.30. For conditions corresponding to high-speed flight, the increase in the drag was 30 percent of the profile drag of the smooth airfoil for the roughness produced by spray painting and 63 percent for the roughness produced. by 0.0037-inch carborundum grains. About one-half the drag increase was caused by the roughness on the forward one-fourth of the airfoil. Sandpapering the painted surface with No. 400 sandpaper made it sufficiently smooth that the drag was no greater than when the surface was polished. In the lower part of the range investigated the drag due to roughness increased rapidly with Reynolds Number.

Gliding flight: speed and acceleration of ideal falcons during diving and pull out.

PubMed

Tucker

1998-01-14

Some falcons, such as peregrines (Falco peregrinus), attack their prey in the air at the end of high-speed dives and are thought to be the fastest of animals. Estimates of their top speed in a dive range up to 157 m s-1, although speeds this high have never been accurately measured. This study investigates the aerodynamic and gravitational forces on 'ideal falcons' and uses a mathematical model to calculate speed and acceleration during diving. Ideal falcons have body masses of 0.5-2.0 kg and morphological and aerodynamic properties based on those measured for real falcons. The top speeds reached during a dive depend on the mass of the bird and the angle and duration of the dive. Given enough time, ideal falcons can reach top speeds of 89-112 m s-1 in a vertical dive, the higher speed for the heaviest bird, when the parasite drag coefficient has a value of 0.18. This value was measured for low-speed flight, and it could plausibly decline to 0.07 at high speeds. Top speeds then would be 138-174 m s-1. An ideal falcon diving at angles between 15 and 90 degrees with a mass of 1 kg reaches 95 % of top speed after travelling approximately 1200 m. The time and altitude loss to reach 95 % of top speed range from 38 s and 322 m at 15 degrees to 16 s and 1140 m at 90 degrees, respectively. During pull out at top speed from a vertical dive, the 1 kg ideal falcon can generate a lift force 18 times its own weight by reducing its wing span, compared with a lift force of 1.7 times its weight at full wing span. The falcon loses 60 m of altitude while pulling out of the dive, and lift and loss of altitude both decrease as the angle of the dive decreases. The 1 kg falcon can slow down in a dive by increasing its parasite drag and the angle of attack of its wings. Both lift and drag increase with angle of attack, but the falcon can cancel the increased lift by holding its wings in a cupped position so that part of the lift is directed laterally. The increased drag of wings producing

D-558-1 on the ramp

NASA Technical Reports Server (NTRS)

1949-01-01

This 1949 NACA Muroc Flight Test Unit photograph of the Douglas D-558-1 #3 Skystreak was taken in front of the NACA hangar at South Base, Edwards Air Force. NACA had the color of the Skystreaks changed from red to white for better optical tracking and photograpy. It was found that the dark red aircraft was hard to see against the dark blue sky over Edwards Air Force Base. The NACA Muroc Flight Test Unit went through several names before the organization became the NASA Dryden Flight Research Center in 1976. Conceived in 1945, the D558-1 Skystreak was designed by the Douglas Aircraft Company for the U.S. Navy Bureau of Aeronautics, in conjunction with the National Advisory Committee for Aeronautics (NACA). The Skystreaks were turojet powered aircraft that took off from the ground under their own power and had straight wings and tails. All three D-558-1 Skystreaks were powered by Allison J35-A-11 turbojet engines producing 5,000 pounds of thrust. All the Skystreaks were initially painted scarlet, which lead to the nickname 'crimson test tube.' NACA later had the color of the Skystreaks changed to white to improve optical tracking and photography. The Skystreaks carried 634 pounds of instrumentation and were ideal first-generation, simple, transonic research airplanes. Much of the research performed by the D-558-1 Skystreaks, was quickly overshadowed in the public mind by Chuck Yeager and the X-1 rocketplane. However, the Skystreak performed an important role in aeronautical research by flying for extended periods of time at transonic speeds, which freed the X-1 to fly for limited periods at supersonic speeds.

Heat transfer measurements from a NACA 0012 airfoil in flight and in the NASA Lewis icing research tunnel. M.S. Thesis Final Report

NASA Technical Reports Server (NTRS)

Poinsatte, Philip E.

1990-01-01

Local heat transfer coefficients from a smooth and roughened NACA 0012 airfoil were measured using a steady state heat flux method. Heat transfer measurements on the specially constructed 0.533 meter chord airfoil were made both in flight on the NASA Lewis Twin Otter Research Aircraft and in the NASA Lewis Icing Research Tunnel (IRT). Roughness was obtained by the attachment of small, 2 mm diameter, hemispheres of uniform size to the airfoil surface in four distinct patterns. The flight data was taken for the smooth and roughened airfoil at various Reynolds numbers based on chord in the range of 1.24x10(exp 6) to 2.50x10(exp 6) and at various angles of attack up to 4 degrees. During these flight tests the free stream velocity turbulence intensity was found to be very low (less than 0.1 percent). The wind tunnel data was taken in the Reynolds number range of 1.20x10(exp 6) to 4.52x10(exp 6) and at angles of attack from -4 degrees to +8 degrees. The turbulence intensity in the IRT was 0.5 to 0.7 percent with the cloud making spray off. Results for both the flight and tunnel tests are presented as Frossling number based on chord versus position on the airfoil surface for various roughnesses and angle of attack. A table of power law curve fits of Nusselt number as a function of Reynolds number is also provided. The higher level of turbulence in the IRT versus flight had little effect on heat transfer for the lower Reynolds numbers but caused a moderate increase in heat transfer at the higher Reynolds numbers. Turning on the cloud making spray air in the IRT did not alter the heat transfer. Roughness generally increased the heat transfer by locally disturbing the boundary layer flow. Finally, the present data was not only compared with previous airfoil data where applicable, but also with leading edge cylinder and flat plate heat transfer values which are often used to estimate airfoil heat transfer in computer codes.

Hurricane Imaging Radiometer Wind Speed and Rain Rate Retrievals during the 2010 GRIP Flight Experiment

NASA Technical Reports Server (NTRS)

Sahawneh, Saleem; Farrar, Spencer; Johnson, James; Jones, W. Linwood; Roberts, Jason; Biswas, Sayak; Cecil, Daniel

2014-01-01

Microwave remote sensing observations of hurricanes, from NOAA and USAF hurricane surveillance aircraft, provide vital data for hurricane research and operations, for forecasting the intensity and track of tropical storms. The current operational standard for hurricane wind speed and rain rate measurements is the Stepped Frequency Microwave Radiometer (SFMR), which is a nadir viewing passive microwave airborne remote sensor. The Hurricane Imaging Radiometer, HIRAD, will extend the nadir viewing SFMR capability to provide wide swath images of wind speed and rain rate, while flying on a high altitude aircraft. HIRAD was first flown in the Genesis and Rapid Intensification Processes, GRIP, NASA hurricane field experiment in 2010. This paper reports on geophysical retrieval results and provides hurricane images from GRIP flights. An overview of the HIRAD instrument and the radiative transfer theory based, wind speed/rain rate retrieval algorithm is included. Results are presented for hurricane wind speed and rain rate for Earl and Karl, with comparison to collocated SFMR retrievals and WP3D Fuselage Radar images for validation purposes.

An Investigation of the Drag of Windshields in the 8-Foot High-Speed Wind Tunnel

NASA Technical Reports Server (NTRS)

Robinson, Russell G.; Delano, James B.

1939-01-01

The drag of closed-cockpit and transport-type windshields was determined from tests made at speeds from 200 to 440 miles per hour in the NACA 8-foot high-speed wind tunnel. This speed range corresponds to a test Reynolds number range of 2,510,000 to 4,830,000 based on the mean aerodynamic chord of the full-span model (17.29 inches). The shapes of the windshield proper, the hood, and the tail fairing were systematically varied to include common types and a refined design. Transport types varied from a reproduction of a current type to a completely faired windshield. The results show that the drag of windshields of the same frontal area, on airplanes of small to medium size, may account for 15% of the airplane drag or may be reduced to 1%. Optimum values are given for windshield and tail-fairing lengths; the effect, at various radii is shown. The longitudinal profile of a windshield is shown to be most important and the transverse profile, to be much less important. The effects of retaining strips, of steps for telescoping hoods, and of recessed windows are determined. The results show that the drag of transport-type windshields may account for 21% of the fuselage drag or may be reduced to 2%.

High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography

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

Ronzhin, A.; Los, S.; Martens, M.

2011-02-01

We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomographymore » (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile, lack of high

Summary of a Crew-Centered Flight Deck Design Philosophy for High-Speed Civil Transport (HSCT) Aircraft

NASA Technical Reports Server (NTRS)

Palmer, Michael T.; Rogers, William H.; Press, Hayes N.; Latorella, Kara A.; Abbott, Terence S.

1995-01-01

Past flight deck design practices used within the U.S. commercial transport aircraft industry have been highly successful in producing safe and efficient aircraft. However, recent advances in automation have changed the way pilots operate aircraft, and these changes make it necessary to reconsider overall flight deck design. Automated systems have become more complex and numerous, and often their inner functioning is partially or fully opaque to the flight crew. Recent accidents and incidents involving autoflight system mode awareness Dornheim, 1995) are an example. This increase in complexity raises pilot concerns about the trustworthiness of automation, and makes it difficult for the crew to be aware of all the intricacies of operation that may impact safe flight. While pilots remain ultimately responsible for mission success, performance of flight deck tasks has been more widely distributed across human and automated resources. Advances in sensor and data integration technologies now make far more information available than may be prudent to present to the flight crew.

77 FR 69572 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection: High Speed...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-20

... Envelope Protection: High Speed Limiting AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice... inadvertently or intentionally exceeding a speed approximately equivalent to V FC or attaining V DF . Current Title 14 Code of Federal Regulations (14 CFR) part 25 do not relate to a high speed limiter that might...

Time-of-Flight Measurement of the Speed of Sound in a Metal Bar

ERIC Educational Resources Information Center

Ganci, Salvatore

2016-01-01

A simple setup was designed for a "time-of-flight" measurement of the sound speed in a metal bar. The experiment requires low cost components and is very simple to understand by students. A good use of it is as a demonstration experiment.

Math modeling for helicopter simulation of low speed, low altitude and steeply descending flight

NASA Technical Reports Server (NTRS)

Sheridan, P. F.; Robinson, C.; Shaw, J.; White, F.

1982-01-01

A math model was formulated to represent some of the aerodynamic effects of low speed, low altitude, and steeply descending flight. The formulation is intended to be consistent with the single rotor real time simulation model at NASA Ames Research Center. The effect of low speed, low altitude flight on main rotor downwash was obtained by assuming a uniform plus first harmonic inflow model and then by using wind tunnel data in the form of hub loads to solve for the inflow coefficients. The result was a set of tables for steady and first harmonic inflow coefficients as functions of ground proximity, angle of attack, and airspeed. The aerodynamics associated with steep descending flight in the vortex ring state were modeled by replacing the steady induced downwash derived from momentum theory with an experimentally derived value and by including a thrust fluctuations effect due to vortex shedding. Tables of the induced downwash and the magnitude of the thrust fluctuations were created as functions of angle of attack and airspeed.

F-100A on ramp

NASA Technical Reports Server (NTRS)

1957-01-01

North American F-100A Super Sabre on the ramp near the NACA High-Speed Flight Station in 1957. Some airplane characteristics are: Fuselage length, feet 45.64 Wing span, feet Original wing 36.58 Extended wing 38.58 Power Plant: Pratt & Whitney J57-P7 turbojet engine with afterburner Airplane weight, pounds: Basic (without fuel, oil, water, pilot) 19,662

Blended-Wing-Body Low-Speed Flight Dynamics: Summary of Ground Tests and Sample Results

NASA Technical Reports Server (NTRS)

Vicroy, Dan D.

2009-01-01

A series of low-speed wind tunnel tests of a Blended-Wing-Body tri-jet configuration to evaluate the low-speed static and dynamic stability and control characteristics over the full envelope of angle of attack and sideslip are summarized. These data were collected for use in simulation studies of the edge-of-the-envelope and potential out-of-control flight characteristics. Some selected results with lessons learned are presented.

Index of NACA Technical Publications, July 1956 - June 1957

NASA Technical Reports Server (NTRS)

1957-01-01

This index of NACA Technical Publications covers the NACA research reports issued in the period of July 1956 through June 1957. It is the sixth supplement to the basic 1915-1949 Index. The research reports issued prior to July 1956 which have been declassified since that date have also been included. A list of these reports may be found on pages 243-244. Cards for this list may be discarded as entries for them are included in this Index. Current announcement of newly declassified materials is regularly made in the NACA Research Abstracts and Reclassification Notice. The arrangement of this Index follows: (1) Explanatory chart of NACA publications series designations, (2) outline of subject classification system, (3) chronological list of NACA reports under each subject classification, (4) list of reports declassified from July 1956 through June 1957, (5) alphabetical index to subject categories, and (6) author index. Entries included herein duplicate in part the information of the index cards furnished with the individual research reports. Recipients maintaining card files may wish to discard those index cards on hand for unclassified research reports issued during the July 1956-June 1957 period. Such cards were printed on yellow stock for easy identification in the discard process. Please note that some classified reports issued during the July-December 1956 period are included in the yellow stock area. Therefore care must be taken to avoid destroying such cards. Newly available research reports are currently announced in the NACA Research Abstracts and Reclassification Notice and are normally available for a period of five years after announcement. Most of the older research reports (those issued prior to July 1952) are thus available on a "loan only" basis within the United states.

Dr. Igor Sikorsky Visits the Lewis Flight Propulsion Laboratory

NASA Image and Video Library

1951-06-21

Dr. Igor Sikorsky, fourth from the left, visits the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory in Cleveland, Ohio. The legendary Russian-born aviation pioneer visited NACA Lewis several times during the 1940s and 1950s. In 1946 Sikorsky arrived at Lewis for the 1946 National Air Races, which included demonstrations by five of his helicopters. NACA flight mechanic Joseph Sikosky personally escorted Sikorsky during the visit. Sikorsky frequently addressed local professional organizations, such as the American Society of Mechanical Engineers, during his visits. Sikorsky built and flew the first multi-engine aircraft as a youth in Russia. In his mid-20s Sikorsky designed and oversaw the manufacturing of 75 four-engine bombers. During the Bolshevik Revolution he fled to New York City where he worked jobs outside of aviation. In 1923 Sikorsky obtained funding to build a twin-engine water aircraft. This aircraft was the first US twin-engine flying machine and a world-wide success. In 1939 Sikorsky designed the first successful US helicopter. He then put all of his efforts into helicopters, and built some of the most successful helicopters in use today. Sikorsky passed away in 1972. From left to right: unknown; John Collins, Chief of the Engine Performance and Materials Division; Abe Silverstein, Chief of Research; Sikorsky; lab Director Ray Sharp; and Executive Officer Robert Sessions.

Technology needs for high speed rotorcraft (2)

NASA Technical Reports Server (NTRS)

Scott, Mark W.

1991-01-01

An analytical study was conducted to identify rotorcraft concepts best capable of combining a cruise speed of 350 to 450 knots with helicopter-like low speed attributes, and to define the technology advancements needed to make them viable by the year 2000. A systematic approach was used to compare the relative attributes and mission gross weights for a wide range of concepts, resulting in a downselect to the most promising concept/mission pairs. For transport missions, tilt-wing and variable diameter tilt-rotor (VDTR) concepts were found to be superior. For a military scout/attack role, the VDTR was best, although a shrouded rotor concept could provide a highly agile, low observable alternative if its weight empty fraction could be reduced. A design speed of 375 to 425 knots was found to be the maximum desirable for transport missions, with higher speed producing rapidly diminishing benefits in productivity. The key technologies that require advancement to make the tilt-wing and VDTR concepts viable are in the areas of wing and proprotor aerodynamics, efficient structural design, flight controls, refinement of the geared flap pitch control system, expansion of the speed/descent envelope, and the structural and aerodynamic tradeoffs of wing thickness and forward sweep. For the shrouded rotor, weight reduction is essential, particularly with respect to the mechanism for covering the rotor in cruise.

High Speed Jet Noise Prediction Using Large Eddy Simulation

NASA Technical Reports Server (NTRS)

Lele, Sanjiva K.

2002-01-01

Current methods for predicting the noise of high speed jets are largely empirical. These empirical methods are based on the jet noise data gathered by varying primarily the jet flow speed, and jet temperature for a fixed nozzle geometry. Efforts have been made to correlate the noise data of co-annular (multi-stream) jets and for the changes associated with the forward flight within these empirical correlations. But ultimately these emipirical methods fail to provide suitable guidance in the selection of new, low-noise nozzle designs. This motivates the development of a new class of prediction methods which are based on computational simulations, in an attempt to remove the empiricism of the present day noise predictions.

B-47A on ramp

NASA Technical Reports Server (NTRS)

1953-01-01

Boeing B-47A (NACA 150) shown on the ramp near NACA High-Speed Flight Research Station at South Base of Edwards Air Force Base, California, in 1953. The B-47A Stratojet's wing is mounted high on the fuselage with a sweep back of 36 degrees and a span of 116 feet, with wing vortex generators installed. A two engine pod under each wing, and an additional engine pod at each wing tip using General Electric J-47-GE-23 turbojets. The airplane is fitted with a nose boom for measuring airspeed, altitude, angle-of-attack and angle-of-sideslip, and an optigraph for measuring the movements of target lights on the wing and tail.

An experimental low Reynolds number comparison of a Wortmann FX67-K170 airfoil, a NACA 0012 airfoil and a NACA 64-210 airfoil in simulated heavy rain

NASA Technical Reports Server (NTRS)

Craig, Anthony P.; Hansman, R. John

1987-01-01

Wind tunnel experiments were conducted on Wortmann FX67-K170, NACA 0012, and NACA 64-210 airfoils at rain rates of 1000 mm/hr and Reynolds numbers of 310,000 to compare the aerodynamic performance degradation of the airfoils and to attempt to identify the various mechanisms which affect performance in heavy rain conditions. Lift and drag were measured in dry and wet conditions, a variety of flow visualization techniques were employed, and a computational code which predicted airfoil boundary layer behavior was used. At low angles of attack, the lift degradation in wet conditions varied significantly between the airfoils. The Wortmann section had the greatest overall lift degradation and the NACA 64-210 airfoil had the smallest. At high angles of attack, the NACA 64-210 and 0012 airfoils had improved aerodynamic performance in rain conditions due to an apparent reduction of the boundry layer separation. Performance degradation in heavy rain for all three airfoils at low angles of attack could be emulated by forced boundary layer transition near the leading edge. The secondary effect occurs at time scales consistent with top surface water runback times. The runback layer is thought to effectively alter the airfoil geometry. The severity of the performance degradation for the airfoils varied. The relative differences appeared to be related to the susceptibility of each airfoil to premature boundary layer transition.

Piloted Simulation Study of the Effects of High-Lift Aerodynamics on the Takeoff Noise of a Representative High-Speed Civil Transport

NASA Technical Reports Server (NTRS)

Glaab, Louis J.; Riley, Donald R.; Brandon, Jay M.; Person, Lee H., Jr.; Glaab, Patricia C.

1999-01-01

As part of an effort between NASA and private industry to reduce airport-community noise for high-speed civil transport (HSCT) concepts, a piloted simulation study was initiated for the purpose of predicting the noise reduction benefits that could result from improved low-speed high-lift aerodynamic performance for a typical HSCT configuration during takeoff and initial climb. Flight profile and engine information from the piloted simulation were coupled with the NASA Langley Aircraft Noise Prediction Program (ANOPP) to estimate jet engine noise and to propagate the resulting source noise to ground observer stations. A baseline aircraft configuration, which also incorporated different levels of projected improvements in low-speed high-lift aerodynamic performance, was simulated to investigate effects of increased lift and lift-to-drag ratio on takeoff noise levels. Simulated takeoff flights were performed with the pilots following a specified procedure in which either a single thrust cutback was performed at selected altitudes ranging from 400 to 2000 ft, or a multiple-cutback procedure was performed where thrust was reduced by a two-step process. Results show that improved low-speed high-lift aerodynamic performance provides at least a 4 to 6 dB reduction in effective perceived noise level at the FAA downrange flyover measurement station for either cutback procedure. However, improved low-speed high-lift aerodynamic performance reduced maximum sideline noise levels only when using the multiple-cutback procedures.

Modeling and simulation of high-speed wake flows

NASA Astrophysics Data System (ADS)

Barnhardt, Michael Daniel

High-speed, unsteady flows represent a unique challenge in computational hypersonics research. They are found in nearly all applications of interest, including the wakes of reentry vehicles, RCS jet interactions, and scramjet combustors. In each of these examples, accurate modeling of the flow dynamics plays a critical role in design performance. Nevertheless, literature surveys reveal that very little modern research effort has been made toward understanding these problems. The objective of this work is to synthesize current computational methods for high-speed flows with ideas commonly used to model low-speed, turbulent flows in order to create a framework by which we may reliably predict unsteady, hypersonic flows. In particular, we wish to validate the new methodology for the case of a turbulent wake flow at reentry conditions. Currently, heat shield designs incur significant mass penalties due to the large margins applied to vehicle afterbodies in lieu of a thorough understanding of the wake aerothermodynamics. Comprehensive validation studies are required to accurately quantify these modeling uncertainties. To this end, we select three candidate experiments against which we evaluate the accuracy of our methodology. The first set of experiments concern the Mars Science Laboratory (MSL) parachute system and serve to demonstrate that our implementation produces results consistent with prior studies at supersonic conditions. Second, we use the Reentry-F flight test to expand the application envelope to realistic flight conditions. Finally, in the last set of experiments, we examine a spherical capsule wind tunnel configuration in order to perform a more detailed analysis of a realistic flight geometry. In each case, we find that current 1st order in time, 2nd order in space upwind numerical methods are sufficiently accurate to predict statistical measurements: mean, RMS, standard deviation, and so forth. Further potential gains in numerical accuracy are

High-speed civil transport issues and technology program

NASA Technical Reports Server (NTRS)

Hewett, Marle D.

1992-01-01

A strawman program plan is presented, consisting of technology developments and demonstrations required to support the construction of a high-speed civil transport. The plan includes a compilation of technology issues related to the development of a transport. The issues represent technical areas in which research and development are required to allow airframe manufacturers to pursue an HSCT development. The vast majority of technical issues presented require flight demonstrated and validated solutions before a transport development will be undertaken by the industry. The author believes that NASA is the agency best suited to address flight demonstration issues in a concentrated effort. The new Integrated Test Facility at NASA Dryden Flight Research Facility is considered ideally suited to the task of supporting ground validations of proof-of-concept and prototype system demonstrations before night demonstrations. An elaborate ground hardware-in-the-loop (iron bird) simulation supported in this facility provides a viable alternative to developing an expensive fill-scale prototype transport technology demonstrator. Drygen's SR-71 assets, modified appropriately, are a suitable test-bed for supporting flight demonstrations and validations of certain transport technology solutions. A subscale, manned or unmanned flight demonstrator is suitable for flight validation of transport technology solutions, if appropriate structural similarity relationships can be established. The author contends that developing a full-scale prototype transport technology demonstrator is the best alternative to ensuring that a positive decision to develop a transport is reached by the United States aerospace industry.

Experimental Studies of Flow Separation of the NACA 2412 Airfoil at Low Speeds

NASA Technical Reports Server (NTRS)

Seetharam, H. C.; Rodgers, E. J.; Wentz, W. H., Jr.

1997-01-01

Wind tunnel tests have been conducted on an NACA 2412 airfoil section at Reynolds number of 2.2 x 10(exp 6) and Mach number of 0.13. Detailed measurements of flow fields associated with turbulent boundary layers have been obtained at angles of attack of 12.4 degrees, 14.4 degrees, and 16.4 degrees. Pre- and post-separated velocity and pressure survey results over the airfoil and in the associated wake are presented. Extensive force, pressure, tuft survey, hot-film survey, local skin friction, and boundary layer data are also included. Pressure distributions and separation point locations show good agreement with theory for the two layer angles of attack. Boundary layer displacement thickness, momentum thickness, and shape factor agree well with theory up to the point of separation. There is considerable disparity between extent of flow reversal in the wake as measured by pressure and hot-film probes. The difference is attributed to the intermittent nature of the flow reversal.

1998 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

NASA Technical Reports Server (NTRS)

McMillin, S. Naomi (Editor)

1999-01-01

NASA's High-Speed Research Program sponsored the 1998 Aerodynamic Performance Technical Review on February 9-13, in Los Angeles, California. The review was designed to bring together NASA and industry HighSpeed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of. Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, and Flight Controls. The review objectives were to: (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working HSCT aerodynamics. In particular, single and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program.

1998 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

NASA Technical Reports Server (NTRS)

McMillin, S. Naomi (Editor)

1999-01-01

NASA's High-Speed Research Program sponsored the 1998 Aerodynamic Performance Technical Review on February 9-13, in Los Angeles, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, and Flight Controls. The review objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working HSCT aerodynamics. In particular, single and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program.

Visualization of Projectile Flying at High Speed in Dusty Atmosphere

NASA Astrophysics Data System (ADS)

Masaki, Chihiro; Watanabe, Yasumasa; Suzuki, Kojiro

2017-10-01

Considering a spacecraft that encounters particle-laden environment, such as dust particles flying up over the regolith by the jet of the landing thruster, high-speed flight of a projectile in such environment was experimentally simulated by using the ballistic range. At high-speed collision of particles on the projectile surface, they may be reflected with cracking into smaller pieces. On the other hand, the projectile surface will be damaged by the collision. To obtain the fundamental characteristics of such complicated phenomena, a projectile was launched at the velocity up to 400 m/s and the collective behaviour of particles around projectile was observed by the high-speed camera. To eliminate the effect of the gas-particle interaction and to focus on only the effect of the interaction between the particles and the projectile's surface, the test chamber pressure was evacuated down to 30 Pa. The particles about 400μm diameter were scattered and formed a sheet of particles in the test chamber by using two-dimensional funnel with a narrow slit. The projectile was launched into the particle sheet in the tangential direction, and the high-speed camera captured both projectile and particle motions. From the movie, the interaction between the projectile and particle sheet was clarified.

1997 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

NASA Technical Reports Server (NTRS)

Baize, Daniel G. (Editor)

1999-01-01

The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Aerodynamic Performance Workshop on February 25-28, 1997. The workshop was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, Flight Controls, Supersonic Laminar Flow Control, and Sonic Boom Prediction. The workshop objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientist and engineers working HSCT aerodynamics. In particular, single- and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT Motion Simulator results were presented along with executive summaries for all the Aerodynamic Performance technology areas.

1997 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

NASA Technical Reports Server (NTRS)

Baize, Daniel G. (Editor)

1999-01-01

The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Aerodynamic Performance Workshop on February 25-28, 1997. The workshop was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in area of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, Flight Controls, Supersonic Laminar Flow Control, and Sonic Boom Prediction. The workshop objectives were to (1) report the progress and status of HSCT aerodyamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientist and engineers working HSCT aerodynamics. In particular, single- and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT Motion Simulator results were presented along with executive summaries for all the Aerodynamic Performance technology areas.

1997 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

NASA Technical Reports Server (NTRS)

Baize, Daniel G. (Editor)

1999-01-01

The High-Speed Research Program and NASA Langley Research Center sponsored the NASA High-Speed Research Program Aerodynamic Performance Workshop on February 25-28, 1997. The workshop was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in area of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High-Lift, Flight Controls, Supersonic Laminar Flow Control, and Sonic Boom Prediction. The workshop objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientist and engineers working HSCT aerodynamics. In particular, single- and multi-point optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT Motion Simulator results were presented along with executive summaries for all the Aerodynamic Performance technology areas.

F-100 and F-100A on ramp - comparison showing tail modifications that solved control problems during

NASA Technical Reports Server (NTRS)

1955-01-01

On the left is NACA High-Speed Flight Station's North American F-100A (52-5778) Super Sabre with a modified vertical fin. On the right is an Air Force's North American F-100A (52-5773) with the original vertical fin configuration. 1955. NACA added a larger vertical fin to the airplane in December 1954, adding 10 percent more surface area. Later North American installed an even larger fin, having 27 percent greater area, as well as wingtip extensions. The modifications solved the dangerous directional stability and roll coupling problems that the F-100 was experiencing. The F-100 series went on to a long and distinguished service life.

Technology needs for high-speed rotorcraft

NASA Technical Reports Server (NTRS)

Rutherford, John; Orourke, Matthew; Martin, Christopher; Lovenguth, Marc; Mitchell, Clark

1991-01-01

A study to determine the technology development required for high-speed rotorcraft development was conducted. The study begins with an initial assessment of six concepts capable of flight at, or greater than 450 knots with helicopter-like hover efficiency (disk loading less than 50 pfs). These concepts were sized and evaluated based on measures of effectiveness and operational considerations. Additionally, an initial assessment of the impact of technology advances on the vehicles attributes was made. From these initial concepts a tilt wing and rotor/wing concepts were selected for further evaluation. A more detailed examination of conversion and technology trade studies were conducted on these two vehicles, each sized for a different mission.

Impingement of Water Droplets on NACA 65A004 Airfoil at 8 deg Angle of Attack

NASA Technical Reports Server (NTRS)

Brun, R. J.; Gallagher, H. M.; Vogt, D. E.

1954-01-01

The trajectories of droplets in the air flowing past an NACA 65AO04 airfoil at an angle of attack of 8 deg were determined.. The amount of water in droplet form impinging on the airfoil, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface were calculated from the trajectories and presented to cover a large range of flight and atmospheric conditions. These impingement characteristics are compared briefly with those previously reported for the same airfoil at an angle of attack of 4 deg.

Kinematic control of male Allen's Hummingbird wing trill over a range of flight speeds.

PubMed

Clark, Christopher J; Mistick, Emily A

2018-05-18

Wing trills are pulsed sounds produced by modified wing feathers at one or more specific points in time during a wingbeat. Male Allen's Hummingbird ( Selasphorus sasin ) produce a sexually dimorphic 9 kHz wing trill in flight. Here we investigate the kinematic basis for trill production. The wingtip velocity hypothesis posits that trill production is modulated by the airspeed of the wingtip at some point during the wingbeat, whereas the wing rotation hypothesis posits that trill production is instead modulated by wing rotation kinematics. To test these hypotheses, we flew six male Allen's Hummingbirds in an open jet wind tunnel at flight speeds of 0, 3, 6, 9, 12 and 14 m s -1 , and recorded their flight with two 'acoustic cameras' placed below and behind, or below and lateral to the flying bird. The acoustic cameras are phased arrays of 40 microphones that used beamforming to spatially locate sound sources within a camera image. Trill Sound Pressure Level (SPL) exhibited a U-shaped relationship with flight speed in all three camera positions. SPL was greatest perpendicular to the stroke plane. Acoustic camera videos suggest that the trill is produced during supination. The trill was up to 20 dB louder during maneuvers than it was during steady state flight in the wind tunnel, across all airspeeds tested. These data provide partial support for the wing rotation hypothesis. Altered wing rotation kinematics could allow male Allen's Hummingbird to modulate trill production in social contexts such as courtship displays. © 2018. Published by The Company of Biologists Ltd.

NACA Computers Take Readings From Manometer Boards

NASA Image and Video Library

1949-02-21

Female computers at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory copy pressure readings from rows of manometers below the 18- by 18-inch Supersonic Wind Tunnel. The computers obtained test data from the manometers and other instruments, made the initial computations, and plotted the information graphically. Based on these computations, the researchers planned their next test or summarized their findings in a report. Manometers were mercury-filled glass tubes that were used to indicate different pressure levels from inside the test facility or from the test article. Manometers look and function very similarly to thermometers. Dozens of pressure sensing instruments were installed for each test. Each was connected to a manometer tube located inside the control room. The mercury inside the manometer rose and fell with the pressure levels. The dark mercury can be seen in this photograph at different levels within the tubes. Since this activity was dynamic, it was necessary to note the levels at given points during the test. This was done using both computer notations and photography.

Dr. Hugh L. Dryden - portrait

NASA Technical Reports Server (NTRS)

1959-01-01

Dr. Hugh Latimer Dryden, had many titles after his name in his lifetime. In 1949 he became the director of the National Advisory Committee for Aeronautics (NACA). Dr. Dryden received many accolades and awards both during his life and after his death, but the greatest and most appropriate honor came on March 26, 1976, when NASA renamed the NASA Flight Research Center as the NASA Hugh L. Dryden Flight Research Center. At the dedication ceremony NASA Administrator James C. Fletcher stated: 'in 1924, when the fastest racing planes did well to fly at 280 m.p.h., Dryden was already probing the transonic range of . . . flight. Later in the 1920s, he sought to develop methods of accurately measuring . . . turbulence in wind tunnels. In 1938 he was the first American to deliver the Wright Brothers lecture. His 'Turbulence and the Boundary Layer' became a classic summary on the subject. It is most fitting that this Flight Research Center, with its unique and highly specialized capability for solving aerospace problems, should memorialize the genius of Hugh Dryden.' Dr. Dryden was initially an aerodynamicist with the National Bureau of Standards. He did important early work in high-speed aerodynamics. In 1947 he became the director of aeronautical research for the NACA (a predecessor of the National Aeronautics and Space Administration). Two years later, he became NACA's director, a position he held until 1958 when he became deputy administrator of NASA.

Joseph A. Walker after X-15 flight #2-14-28

NASA Image and Video Library

1961-03-30

Joseph A. Walker was a Chief Research Pilot at the NASA Dryden Flight Research Center during the mid-1960s. He joined the NACA in March 1945, and served as project pilot at the Edwards flight research facility on such pioneering research projects as the D-558-1, D-558-2, X-1, X-3, X-4, X-5, and the X-15. He also flew programs involving the F-100, F-101, F-102, F-104, and the B-47. Walker made the first NASA X-15 flight on March 25, 1960. He flew the research aircraft 24 times and achieved its fastest speed and highest altitude. He attained a speed of 4,104 mph (Mach 5.92) during a flight on June 27, 1962, and reached an altitude of 354,300 feet on August 22, 1963 (his last X-15 flight). He was the first man to pilot the Lunar Landing Research Vehicle (LLRV) that was used to develop piloting and operational techniques for lunar landings. Walker was born February 20, 1921, in Washington, Pa. He lived there until graduating from Washington and Jefferson College in 1942, with a B.A. degree in Physics. During World War II he flew P-38 fighters for the Air Force, earning the Distinguished Flying Cross and the Air Medal with Seven Oak Clusters. Walker was the recipient of many awards during his 21 years as a research pilot. These include the 1961 Robert J. Collier Trophy, 1961 Harmon International Trophy for Aviators, the 1961 Kincheloe Award and 1961 Octave Chanute Award. He received an honorary Doctor of Aeronautical Sciences degree from his alma mater in June of 1962. Walker was named Pilot of the Year in 1963 by the National Pilots Association. He was a charter member of the Society of Experimental Test Pilots, and one of the first to be designated a Fellow. He was fatally injured on June 8, 1966, in a mid-air collision between an F-104 he was piloting and the XB-70.

Interference of Tail Surfaces and Wing and Fuselage from Tests of 17 Combinations in the N.A.C.A. Variable-Density Tunnel

NASA Technical Reports Server (NTRS)

Sherman, Albert

1939-01-01

An investigation of the interference associated with tail surfaces added to wing-fuselage combinations was included in the interference program in progress in the NACA variable-density tunnel. The results indicate that, in aerodynamically clean combinations, the increment to the high-speed drag can be estimated from section characteristics within useful limits of accuracy. The interference appears mainly as effects on the downwash angel and as losses in the tail. An interference burble, which markedly increases the glide-path angle and the stability in pitch before the actual stall, may be considered a means of obtaining satisfactory stalling characteristics for a complete combination.

3-D Stall Cell Inducement Using Static Trips on a NACA0015 Airfoil

NASA Astrophysics Data System (ADS)

Dell'Orso, Haley; Amitay, Michael

2015-11-01

Stall cells typically occur at high angles of attack and moderate to high Reynolds numbers (105 to 106) , which are applicable to High Altitude Long Endurance (HALE) vehicles. Under certain conditions stall cells can form abruptly and have a severe and detrimental impact on flight. In order to better understand this phenomenon, stall cell formation is studied using oil flow visualization and SPIV on a NACA0015 airfoil with AR = 2.67. It was shown that there is a critical Reynolds number above which stall cells begin to form, and that Recrit varies with angle of attack. Zig-zag tape and balsa wood trips were used to induce stall cells at lower Reynolds numbers than they would otherwise be present. This will aid in understanding the formation mechanism of these cells. It was also demonstrated that, in the case of full span trips, stall cells are induced by the 3-D nature of zig-zag trips and did not appear when balsa wood trips were used. This suggests that the formation of the stall cell might be due to 3-D disturbances that are naturally present in a flow field. AFOSR Grant Number FA9550-13-1-0059.

In-flight flow visualization with pressure measurements at low speeds on the NASA F-18 high alpha research vehicle

NASA Technical Reports Server (NTRS)

Delfrate, John H.; Fisher, David F.; Zuniga, Fanny A.

1990-01-01

In-flight results from surface and off-surface flow visualizations and from extensive pressure distributions document the vortical flow on the leading edge extensions (LEX) and forebody of the NASA F-18 high alpha research vehicle for low speeds and angles of attack up to 50 degs. Surface flow visualization data, obtained using the emitted fluid technique, were used to define separation lines and laminar separation bubbles. Off-surface flow visualization data, obtained by smoke injection, were used to document both the path of the vortex cores and the location of vortex core breakdown. The location of vortex core breakdown correlated well with the loss of suction pressure on the LEX and with the flow visualization results from ground facilities. Surface flow separation lines on the LEX and forebody corresponded well with the end of pressure recovery under the vortical flows. Correlation of the pressures with wind tunnel results show fair to good correlation.

Charts for Estimating Tail-rotor Contribution to Helicopter Directional Stability and Control in Low-Speed Flight

NASA Technical Reports Server (NTRS)

Amer, Kenneth B; Gessow, Alfred

1955-01-01

Theoretically derived charts and equations are presented by which tail-rotor design studies of directional trim and control response at low forward speed can be conveniently made. The charts can also be used to obtain the main-rotor stability derivatives of thrust with respect to collective pitch and angle of attack at low forward speeds. The use of the charts and equations for tail-rotor design studies is illustrated. Comparisons between theoretical and experimental results are presented. The charts indicate, and flight tests confirm, that the region of vortex roughness which is familiar for the main rotor is also encountered by the tail rotor and that prolonged operation at the corresponding flight conditions would be difficult.

High-speed and ultrahigh-speed cinematographic recording techniques

NASA Astrophysics Data System (ADS)

Miquel, J. C.

1980-12-01

A survey is presented of various high-speed and ultrahigh-speed cinematographic recording systems (covering a range of speeds from 100 to 14-million pps). Attention is given to the functional and operational characteristics of cameras and to details of high-speed cinematography techniques (including image processing, and illumination). A list of cameras (many of them French) available in 1980 is presented

Low-speed wind-tunnel investigation of the flight dynamic characteristics of an advanced turboprop business/commuter aircraft configuration

NASA Technical Reports Server (NTRS)

Coe, Paul L., Jr.; Turner, Steven G.; Owens, D. Bruce

1990-01-01

An investigation was conducted to determine the low-speed flight dynamic behavior of a representative advanced turboprop business/commuter aircraft concept. Free-flight tests were conducted in the NASA Langley Research Center's 30- by 60-Foot Tunnel. In support of the free-flight tests, conventional static, dynamic, and free-to-roll oscillation tests were performed. Tests were intended to explore normal operating and post stall flight conditions, and conditions simulating the loss of power in one engine.

Flight Test Series 3: Flight Test Report

NASA Technical Reports Server (NTRS)

Marston, Mike; Sternberg, Daniel; Valkov, Steffi

2015-01-01

This document is a flight test report from the Operational perspective for Flight Test Series 3, a subpart of the Unmanned Aircraft System (UAS) Integration in the National Airspace System (NAS) project. Flight Test Series 3 testing began on June 15, 2015, and concluded on August 12, 2015. Participants included NASA Ames Research Center, NASA Armstrong Flight Research Center, NASA Glenn Research Center, NASA Langley Research center, General Atomics Aeronautical Systems, Inc., and Honeywell. Key stakeholders analyzed their System Under Test (SUT) in two distinct configurations. Configuration 1, known as Pairwise Encounters, was subdivided into two parts: 1a, involving a low-speed UAS ownship and intruder(s), and 1b, involving a high-speed surrogate ownship and intruder. Configuration 2, known as Full Mission, involved a surrogate ownship, live intruder(s), and integrated virtual traffic. Table 1 is a summary of flights for each configuration, with data collection flights highlighted in green. Section 2 and 3 of this report give an in-depth description of the flight test period, aircraft involved, flight crew, and mission team. Overall, Flight Test 3 gathered excellent data for each SUT. We attribute this successful outcome in large part from the experience that was acquired from the ACAS Xu SS flight test flown in December 2014. Configuration 1 was a tremendous success, thanks to the training, member participation, integration/testing, and in-depth analysis of the flight points. Although Configuration 2 flights were cancelled after 3 data collection flights due to various problems, the lessons learned from this will help the UAS in the NAS project move forward successfully in future flight phases.

Windtunnel Rebuilding And Extrapolation To Flight At Transsonic Speed For ExoMars

NASA Astrophysics Data System (ADS)

Fertig, Markus; Neeb, Dominik; Gulhan, Ali

2011-05-01

The static as well as the dynamic behaviour of the EXOMARS vehicle in the transonic velocity regime has been investigated experimentally by the Supersonic and Hypersonic Technology Department of DLR in order to investigate the behaviour prior to parachute opening. Since the experimental work was performed in air, a numerical extrapolation to flight by means of CFD is necessary. At low supersonic speed this extrapolation to flight was performed by the Spacecraft Department of the Institute of Flow Technology of DLR employing the CFD code TAU. Numerical as well as experimental results for the wind tunnel test at Mach 1.2 will be compared and discussed for three different angles of attack.

Impingement of Water Droplets on NACA 65A004 Airfoil and Effect of Change in Airfoil Thickness from 12 to 4 Percent at 4 deg Angle of Attack

NASA Technical Reports Server (NTRS)

Brun, Rinaldo J.; Gallagher, Helen M.; Vogt, Dorothea E.

1953-01-01

The trajectories of droplets in the air flowing past an NACA 65A004 a irfoil at an angle of attack of 4 deg were determined. The amount of water in droplet form impinging on the airfoil, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface were calculated from the trajectories and presented to cover a large range of flight and atmospheric conditions. The effect of a change in airfoil thickness from 12 to 4 percent at 4 deg angle of attack is presented by comparing the impingement calculations for the NACA 65A004 airfoil with those for the NACA 65(sub 1)-208 and 65(sub 1)-212 airfoils. The rearward limit of impingement on the upper surface decreases as the airfoil thickness decreases. The rearward limit of impingement on the lower surface increases with a decrease in airfoil t hickness. The total water intercepted decreases as the airfoil thickness is decreased.

Na/Ca Ratio in Large Benthic Foraminifera as a Novel Proxy for Past Ocean Calcium

NASA Astrophysics Data System (ADS)

Rosenthal, Y.; Hauzer, H.; Evans, D.; Erez, J.

2017-12-01

Culture experiments with Operculina ammonoides (a large symbiont bearing benthic foraminifer and an extant relative of the Eocene Nummulites) were carried out varying seawater [Ca], temperature and salinity. The main results of these experiments are: 1. Na/Ca in these foraminifera shells varies with the Na/Ca ratio in the seawater 2. Na/Ca shows small, non-systematic variations with temperature (22-28 ºC) that are within our analytical precision. 3. Na/Ca in the shells show very low changes, increasing linearly with salinity. The sensitivity to salinity is very low compared to that caused by changes of Na/Ca in seawater. Over the seawater experimental range of Na/Ca (10-18 mM), a change of 5 ppt salinity induced a slight Na/Ca increase comparable to the analytical error for Na, or that caused by temperature. Initial reconstructions of seawater [Ca], based on these calibrations, generally agree well with previous models and reconstructions confirming that seawater [Ca] concentrations were substantially higher during the early-mid Cenozoic than today.

Fifty Years of Flight Research: An Annotated Bibliography of Technical Publications of NASA Dryden Flight Research Center, 1946-1996

NASA Technical Reports Server (NTRS)

Fisher, David F.

1999-01-01

Titles, authors, report numbers, and abstracts are given for more than 2200 unclassified and unrestricted technical reports and papers published from September 1946 to December 1996 by NASA Dryden Flight Research Center and its predecessor organizations. These technical reports and papers describe and give the results of 50 years of flight research performed by the NACA and NASA, from the X-1 and other early X-airplanes, to the X-15, Space Shuttle, X-29 Forward Swept Wing, and X-31 aircraft. Some of the other research airplanes tested were the D-558, phase 1 and 2; M-2, HL-10 and X-24 lifting bodies; Digital Fly-By-Wire and Supercritical Wing F-8; XB-70; YF-12; AFTI F-111 TACT and MAW; F-15 HiDEC; F-18 High Alpha Research Vehicle, and F-18 Systems Research Aircraft. The citations of reports and papers are listed in chronological order, with author and aircraft indices. In addition, in the appendices, citations of 233 contractor reports, more than 200 UCLA Flight System Research Center reports and 25 video tapes are included.

Flight Investigation of the Low-Speed Characteristics of a 45 deg Swept-Wing Fighter-Type Airplane with Blowing Boundary-Layer Control Applied to the Leading- and Trailing-Edge Flaps

NASA Technical Reports Server (NTRS)

Quigley, Hervey C.; Anderson, Seth B.; Innis, Robert C.

1960-01-01

A flight investigation has been conducted to study how pilots use the high lift available with blowing-type boundary-layer control applied to the leading- and trailing-edge flaps of a 45 deg. swept-wing airplane. The study includes documentation of the low-speed handling qualities as well as the pilots' evaluations of the landing-approach characteristics. All the pilots who flew the airplane considered it more comfortable to fly at low speeds than any other F-100 configuration they had flown. The major improvements noted were the reduced stall speed, the improved longitudinal stability at high lift, and the reduction in low-speed buffet. The study has shown the minimum comfortable landing-approach speeds are between 120.5 and 126.5 knots compared to 134 for the airplane with a slatted leading edge and the same trailing-edge flap. The limiting factors in the pilots' choices of landing-approach speeds were the limits of ability to control flight-path angle, lack of visibility, trim change with thrust, low static directional stability, and sluggish longitudinal control. Several of these factors were found to be associated with the high angles of attack, between 13 deg. and 15 deg., required for the low approach speeds. The angle of attack for maximum lift coefficient was 28 deg.

1999 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

NASA Technical Reports Server (NTRS)

Hahne, David E. (Editor)

1999-01-01

NASA's High-Speed Research Program sponsored the 1999 Aerodynamic Performance Technical Review on February 8-12, 1999 in Anaheim, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in the areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High Lift, and Flight Controls. The review objectives were to: (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working on HSCT aerodynamics. In particular, single and midpoint optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented, along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program. This Volume 1/Part 1 publication covers configuration aerodynamics.

1999 NASA High-Speed Research Program Aerodynamic Performance Workshop. Volume 1; Configuration Aerodynamics

NASA Technical Reports Server (NTRS)

Hahne, David E. (Editor)

1999-01-01

NASA's High-Speed Research Program sponsored the 1999 Aerodynamic Performance Technical Review on February 8-12, 1999 in Anaheim, California. The review was designed to bring together NASA and industry High-Speed Civil Transport (HSCT) Aerodynamic Performance technology development participants in the areas of Configuration Aerodynamics (transonic and supersonic cruise drag prediction and minimization), High Lift, and Flight Controls. The review objectives were to (1) report the progress and status of HSCT aerodynamic performance technology development; (2) disseminate this technology within the appropriate technical communities; and (3) promote synergy among the scientists and engineers working on HSCT aerodynamics. In particular, single and midpoint optimized HSCT configurations, HSCT high-lift system performance predictions, and HSCT simulation results were presented, along with executive summaries for all the Aerodynamic Performance technology areas. The HSR Aerodynamic Performance Technical Review was held simultaneously with the annual review of the following airframe technology areas: Materials and Structures, Environmental Impact, Flight Deck, and Technology Integration. Thus, a fourth objective of the Review was to promote synergy between the Aerodynamic Performance technology area and the other technology areas of the HSR Program. This Volume 1/Part 2 publication covers the design optimization and testing sessions.

Molecular-Based Optical Measurement Techniques for Transition and Turbulence in High-Speed Flow

NASA Technical Reports Server (NTRS)

Bathel, Brett F.; Danehy, Paul M.; Cutler, Andrew D.

2013-01-01

High-speed laminar-to-turbulent transition and turbulence affect the control of flight vehicles, the heat transfer rate to a flight vehicle's surface, the material selected to protect such vehicles from high heating loads, the ultimate weight of a flight vehicle due to the presence of thermal protection systems, the efficiency of fuel-air mixing processes in high-speed combustion applications, etc. Gaining a fundamental understanding of the physical mechanisms involved in the transition process will lead to the development of predictive capabilities that can identify transition location and its impact on parameters like surface heating. Currently, there is no general theory that can completely describe the transition-to-turbulence process. However, transition research has led to the identification of the predominant pathways by which this process occurs. For a truly physics-based model of transition to be developed, the individual stages in the paths leading to the onset of fully turbulent flow must be well understood. This requires that each pathway be computationally modeled and experimentally characterized and validated. This may also lead to the discovery of new physical pathways. This document is intended to describe molecular based measurement techniques that have been developed, addressing the needs of the high-speed transition-to-turbulence and high-speed turbulence research fields. In particular, we focus on techniques that have either been used to study high speed transition and turbulence or techniques that show promise for studying these flows. This review is not exhaustive. In addition to the probe-based techniques described in the previous paragraph, several other classes of measurement techniques that are, or could be, used to study high speed transition and turbulence are excluded from this manuscript. For example, surface measurement techniques such as pressure and temperature paint, phosphor thermography, skin friction measurements and

NACA Conference on Aircraft Loads, Flutter, and Structures: A compilation of Papers Presented.

DTIC Science & Technology

1953-03-04

Variation of Atmospheric Turbulence With Altitude and Its Effect on Airplane Gust Loads . . . by Robert L. McDougal, Thomas L. Coleman, and Philip L. Smith ...SKOPINSKI, T. H. NACA - Langley Laboratory xvii CONFIDENTIAL CONFIDENTIAL SMETHERS, Rollo G. Bureau of Aeronautics SMITH , Dana W. NACA Subcommittee on...Aircraft Structural Materials SMITH , Frank C. National Bureau of Standards SMITH , Henry G. Hughes Aircraft Co. SMITH , Howard W. NACA Subcommittee on Aircraft

Key Topics for High-Lift Research: A Joint Wind Tunnel/Flight Test Approach

NASA Technical Reports Server (NTRS)

Fisher, David; Thomas, Flint O.; Nelson, Robert C.

1996-01-01

Future high-lift systems must achieve improved aerodynamic performance with simpler designs that involve fewer elements and reduced maintenance costs. To expeditiously achieve this, reliable CFD design tools are required. The development of useful CFD-based design tools for high lift systems requires increased attention to unresolved flow physics issues. The complex flow field over any multi-element airfoil may be broken down into certain generic component flows which are termed high-lift building block flows. In this report a broad spectrum of key flow field physics issues relevant to the design of improved high lift systems are considered. It is demonstrated that in-flight experiments utilizing the NASA Dryden Flight Test Fixture (which is essentially an instrumented ventral fin) carried on an F-15B support aircraft can provide a novel and cost effective method by which both Reynolds and Mach number effects associated with specific high lift building block flows can be investigated. These in-flight high lift building block flow experiments are most effective when performed in conjunction with coordinated ground based wind tunnel experiments in low speed facilities. For illustrative purposes three specific examples of in-flight high lift building block flow experiments capable of yielding a high payoff are described. The report concludes with a description of a joint wind tunnel/flight test approach to high lift aerodynamics research.

The aerodynamics of flight in an insect flight-mill

PubMed Central

Barkan, Shay; Soroker, Victoria

2017-01-01

Predicting the dispersal of pest insects is important for pest management schemes. Flight-mills provide a simple way to evaluate the flight potential of insects, but there are several complications in relating tethered-flight to natural flight. We used high-speed video to evaluate the effect of flight-mill design on flight of the red palm weevil (Rynchophorous ferruginneus) in four variants of a flight-mill. Two variants had the rotating radial arm pivoted on the main shaft of the rotation axis, allowing freedom to elevate the arm as the insect applied lift force. Two other variants had the pivot point fixed, restricting the radial arm to horizontal motion. Beetles were tethered with their lateral axis horizontal or rotated by 40°, as in a banked turn. Flight-mill type did not affect flight speed or wing-beat frequency, but did affect flapping kinematics. The wingtip internal to the circular trajectory was always moved faster relative to air, suggesting that the beetles were attempting to steer in the opposite direction to the curved trajectory forced by the flight-mill. However, banked beetles had lower flapping asymmetry, generated higher lift forces and lost more of their body mass per time and distance flown during prolonged flight compared to beetles flying level. The results indicate, that flapping asymmetry and low lift can be rectified by tethering the beetle in a banked orientation, but the flight still does not correspond directly to free-flight. This should be recognized and taken into account when designing flight-mills and interoperating their data. PMID:29091924

The aerodynamics of flight in an insect flight-mill.

PubMed

Ribak, Gal; Barkan, Shay; Soroker, Victoria

2017-01-01

Predicting the dispersal of pest insects is important for pest management schemes. Flight-mills provide a simple way to evaluate the flight potential of insects, but there are several complications in relating tethered-flight to natural flight. We used high-speed video to evaluate the effect of flight-mill design on flight of the red palm weevil (Rynchophorous ferruginneus) in four variants of a flight-mill. Two variants had the rotating radial arm pivoted on the main shaft of the rotation axis, allowing freedom to elevate the arm as the insect applied lift force. Two other variants had the pivot point fixed, restricting the radial arm to horizontal motion. Beetles were tethered with their lateral axis horizontal or rotated by 40°, as in a banked turn. Flight-mill type did not affect flight speed or wing-beat frequency, but did affect flapping kinematics. The wingtip internal to the circular trajectory was always moved faster relative to air, suggesting that the beetles were attempting to steer in the opposite direction to the curved trajectory forced by the flight-mill. However, banked beetles had lower flapping asymmetry, generated higher lift forces and lost more of their body mass per time and distance flown during prolonged flight compared to beetles flying level. The results indicate, that flapping asymmetry and low lift can be rectified by tethering the beetle in a banked orientation, but the flight still does not correspond directly to free-flight. This should be recognized and taken into account when designing flight-mills and interoperating their data.

Impact of Increased Football Field Width on Player High-Speed Collision Rate.

PubMed

Joseph, Jacob R; Khalsa, Siri S; Smith, Brandon W; Park, Paul

2017-07-01

High-acceleration head impact is a known risk for mild traumatic brain injury (mTBI) based on studies using helmet accelerometry. In football, offensive and defensive players are at higher risk of mTBI due to increased speed of play. Other collision sport studies suggest that increased playing surface size may contribute to reductions in high-speed collisions. We hypothesized that wider football fields lead to a decreased rate of high-speed collisions. Computer football game simulation was developed using MATLAB. Four wide receivers were matched against 7 defensive players. Each offensive player was randomized to one of 5 typical routes on each play. The ball was thrown 3 seconds into play; ball flight time was 2 seconds. Defensive players were delayed 0.5 second before reacting to ball release. A high-speed collision was defined as the receiver converging with a defensive player within 0.5 second of catching the ball. The simulation counted high-speed collisions for 1 team/season (65 plays/game for 16 games/season = 1040 plays/season) averaged during 10 seasons, and was validated against existing data using standard field width (53.3 yards). Field width was increased in 1-yard intervals up to 58.3 yards. Using standard field width, 188 ± 4 high-speed collisions were seen per team per season (18% of plays). When field width increased by 3 yards, high-speed collision rate decreased to 135 ± 3 per team per season (28% decrease; P < 0.0001). Even small increases in football field width can lead to substantial decline in high-speed collisions, with potential for reducing instances of mTBI in football players. Copyright © 2017 Elsevier Inc. All rights reserved.

Design optimization of high-speed proprotor aircraft

NASA Technical Reports Server (NTRS)

Schleicher, David R.; Phillips, James D.; Carbajal, Kevin B.

1993-01-01

NASA's high-speed rotorcraft (HSRC) studies have the objective of investigating technology for vehicles that have both low downwash velocities and forward flight speed capability of up to 450 knots. This paper investigates a tilt rotor, a tilt wing, and a folding tilt rotor designed for a civil transport mission. Baseline aircraft models using current technology are developed for each configuration using a vertical/short takeoff and landing (V/STOL) aircraft design synthesis computer program to generate converged vehicle designs. Sensitivity studies and numerical optimization are used to illustrate each configuration's key design tradeoffs and constraints. Minimization of the gross takeoff weight is used as the optimization objective function. Several advanced technologies are chosen, and their relative impact on future configurational development is discussed. Finally, the impact of maximum cruise speed on vehicle figures of merit (gross weight, productivity, and direct operating cost) is analyzed. The three most important conclusions from the study are payload ratios for these aircraft will be commensurate with current fixed-wing commuter aircraft; future tilt rotors and tilt wings will be significantly lighter, more productive, and cheaper than competing folding tilt rotors; and the most promising technologies are an advanced-technology proprotor for both tilt rotor and tilt wing and advanced structural materials for the folding tilt rotor.

Embodied linearity of speed control in Drosophila melanogaster.

PubMed

Medici, V; Fry, S N

2012-12-07

Fruitflies regulate flight speed by adjusting their body angle. To understand how low-level posture control serves an overall linear visual speed control strategy, we visually induced free-flight acceleration responses in a wind tunnel and measured the body kinematics using high-speed videography. Subsequently, we reverse engineered the transfer function mapping body pitch angle onto flight speed. A linear model is able to reproduce the behavioural data with good accuracy. Our results show that linearity in speed control is realized already at the level of body posture-mediated speed control and is therefore embodied at the level of the complex aerodynamic mechanisms of body and wings. Together with previous results, this study reveals the existence of a linear hierarchical control strategy, which can provide relevant control principles for biomimetic implementations, such as autonomous flying micro air vehicles.

Embodied linearity of speed control in Drosophila melanogaster

PubMed Central

Medici, V.; Fry, S. N.

2012-01-01

Fruitflies regulate flight speed by adjusting their body angle. To understand how low-level posture control serves an overall linear visual speed control strategy, we visually induced free-flight acceleration responses in a wind tunnel and measured the body kinematics using high-speed videography. Subsequently, we reverse engineered the transfer function mapping body pitch angle onto flight speed. A linear model is able to reproduce the behavioural data with good accuracy. Our results show that linearity in speed control is realized already at the level of body posture-mediated speed control and is therefore embodied at the level of the complex aerodynamic mechanisms of body and wings. Together with previous results, this study reveals the existence of a linear hierarchical control strategy, which can provide relevant control principles for biomimetic implementations, such as autonomous flying micro air vehicles. PMID:22933185

Ultrahigh- and high-speed photography, videography, and photonics '91; Proceedings of the Meeting, San Diego, CA, July 24-26, 1991

NASA Astrophysics Data System (ADS)

Jaanimagi, Paul A.

1992-01-01

This volume presents papers grouped under the topics on advances in streak and framing camera technology, applications of ultrahigh-speed photography, characterizing high-speed instrumentation, high-speed electronic imaging technology and applications, new technology for high-speed photography, high-speed imaging and photonics in detonics, and high-speed velocimetry. The papers presented include those on a subpicosecond X-ray streak camera, photocathodes for ultrasoft X-ray region, streak tube dynamic range, high-speed TV cameras for streak tube readout, femtosecond light-in-flight holography, and electrooptical systems characterization techniques. Attention is also given to high-speed electronic memory video recording techniques, high-speed IR imaging of repetitive events using a standard RS-170 imager, use of a CCD array as a medium-speed streak camera, the photography of shock waves in explosive crystals, a single-frame camera based on the type LD-S-10 intensifier tube, and jitter diagnosis for pico- and femtosecond sources.

Ramjet Model and Technicians in the 8- by 6-Foot Supersonic Wind Tunnel

NASA Image and Video Library

1952-02-21

A researcher at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory checks the setup of a RJM-2 ramjet model in the test section of the 8- by 6-Foot Supersonic Wind Tunnel. The 8- by 6 was not only the laboratory’s first large supersonic wind tunnel, but it was also the NACA’s first facility capable of testing an operating engine at supersonic speeds. The 8- by 6-foot tunnel has been used to study engine inlets, fuel injectors, flameholders, exit nozzles, and controls on ramjet and turbojet propulsion systems. The 8-foot wide and 6-foot tall test section consisted of 1-inch thick steel plates with hatches on the floor and ceiling to facilitate the installation of the test article. The two windows seen on the right wall allowed photographic equipment to be set up. The test section was modified in 1956 to accommodate transonic research. NACA engineers drilled 4,700 holes into the test section walls to reduce transonic pressure disturbances and shock waves. NACA Lewis undertook an extensive research program on ramjets in the 1940s using several of its facilities. Ramjets provide a very simple source of propulsion. They are basically a tube which ingests high speed air, ignites it, and then expels the heated air at a significantly higher velocity. Ramjets are extremely efficient and powerful but can only operate at high speeds. Therefore, they require a booster rocket or aircraft drop to accelerate them to high speeds before they can operate.

Interference of Tail Surfaces and Wing and Fuselage from Tests of 17 Combinations in the N.A.C.A. Variable-Density Tunnel

NASA Technical Reports Server (NTRS)

Sherman, Albert

1939-01-01

An investigation of the interference associated with tail surfaces added to wing-fuselage combinations was included in the interference program in progress in the NACA variable-density tunnel. The results indicate that, in aerodynamically clean combinations, the increment of the high-speed drag can be estimated from section characteristics within useful limits of accuracy. The interference appears mainly as effects on the downwash angle and as losses in the tail effectiveness and varies with the geometry of the combination. An interference burble, which markedly increases the glide-path angle and the stability in pitch before the actual stall, may be considered a means of obtaining satisfactory stalling characteristics for complete combination.

Stardust Interstellar Preliminary Examination IX: High-Speed Interstellar Dust Analog Capture in Stardust Flight-Spare Aerogel

NASA Technical Reports Server (NTRS)

Postberg, F.; Sterken, V.; Achilles, C.; Allen, C.; Bastien, R. K.; Frank, D.; Sandford, S. A.; Zolensky, M. E.; Butterworth, A.; Gainesforth, Z.

2014-01-01

The NASA Stardust mission used silica aerogel slabs to slowly decelerate and capture impinging cosmic dust particles for return to Earth. During this process, impact tracks are generated along the trajectory of the particle into the aerogel. It is believed that the morphology and dimensions of these tracks, together with the state of captured grains at track termini, may be linked to the size, velocity, and density of the impacting cosmic dust grain. Here, we present the results of laboratory hypervelocity impact experiments, during which cosmic dust analog particles (diameters of between 0.2 and 0.4 lm), composed of olivine, orthopyroxene, or an organic polymer, were accelerated onto Stardust flight spare low-density (approximately 0.01 g/cu cm) silica aerogel. The impact velocities (3-21 km/s) were chosen to simulate the range of velocities expected during Stardust's interstellar dust (ISD) collection phases. Track lengths and widths, together with the success of particle capture, are analyzed as functions of impact velocity and particle composition, density, and size. Captured terminal particles from low-density organic projectiles become undetectable at lower velocities than those from similarly sized, denser mineral particles, which are still detectable (although substantially altered by the impact process) at 15 km/s. The survival of these terminal particles, together with the track dimensions obtained during low impact speed capture of small grains in the laboratory, indicates that two of the three best Stardust candidate extraterrestrial grains were actually captured at speeds much lower than predicted. Track length and diameters are, in general, more sensitive to impact velocities than previously expected, which makes tracks of particles with diameters of 0.4 lm and below hard to identify at low capture speeds (<10 km/s). Therefore, although captured intact, the majority of the interstellar dust grains returned to Earth by Stardust remain to be found.

High-speed microstrip multi-anode multichannel plate detector system

NASA Astrophysics Data System (ADS)

Riedo, Andreas; Tulej, Marek; Rohner, Urs; Wurz, Peter

2017-04-01

High-speed detector systems with high dynamic range and pulse width characteristics in the sub-nanosecond regime are mandatory for high resolution and highly sensitive time-of-flight mass spectrometers. Typically, for a reasonable detector area, an impedance-matched anode design is necessary to transmit the registered signal fast and distortion-free from the anode to the signal acquisition system. In this report, a high-speed microstrip multi-anode multichannel plate detector is presented and discussed. The anode consists of four separate active concentric anode segments allowing a simultaneous readout of signal with a dynamic range of about eight orders of magnitude. The impedance matched anode segments show pulse width of about 250 ps, measured at full width at half maximum, and rise time of ˜170 ps, measured with an oscilloscope with a sampling rate of 20 GS/s and 4 GHz analogue bandwidth. The usage of multichannel plates as signal amplifier allowed the design of a lightweight, low power consuming, and compact detector system, suitable, e.g., for the integration into space instrumentation or portable systems where size, weight, and power consumption are limited parameters.

Ground-to-Flight Handling Qualities Comparisons for a High Performance Airplane

NASA Technical Reports Server (NTRS)

Brandon, Jay M.; Glaab, Louis J.; Brown, Philip W.; Phillips, Michael R.

1995-01-01

A flight test program was conducted in conjunction with a ground-based piloted simulation study to enable a comparison of handling qualities ratings for a variety of maneuvers between flight and simulation of a modern high performance airplane. Specific objectives included an evaluation of pilot-induced oscillation (PIO) tendencies and a determination of maneuver types which result in either good or poor ground-to-flight pilot handling qualities ratings. A General Dynamics F-16XL aircraft was used for the flight evaluations, and the NASA Langley Differential Maneuvering Simulator was employed for the ground based evaluations. Two NASA research pilots evaluated both the airplane and simulator characteristics using tasks developed in the simulator. Simulator and flight tests were all conducted within approximately a one month time frame. Maneuvers included numerous fine tracking evaluations at various angles of attack, load factors and speed ranges, gross acquisitions involving longitudinal and lateral maneuvering, roll angle captures, and an ILS task with a sidestep to landing. Overall results showed generally good correlation between ground and flight for PIO tendencies and general handling qualities comments. Differences in pilot technique used in simulator evaluations and effects of airplane accelerations and motions are illustrated.

The mechanics and behavior of cliff swallows during tandem flights.

PubMed

Shelton, Ryan M; Jackson, Brandon E; Hedrick, Tyson L

2014-08-01

Cliff swallows (Petrochelidon pyrrhonota) are highly maneuverable social birds that often forage and fly in large open spaces. Here we used multi-camera videography to measure the three-dimensional kinematics of their natural flight maneuvers in the field. Specifically, we collected data on tandem flights, defined as two birds maneuvering together. These data permit us to evaluate several hypotheses on the high-speed maneuvering flight performance of birds. We found that high-speed turns are roll-based, but that the magnitude of the centripetal force created in typical maneuvers varied only slightly with flight speed, typically reaching a peak of ~2 body weights. Turning maneuvers typically involved active flapping rather than gliding. In tandem flights the following bird copied the flight path and wingbeat frequency (~12.3 Hz) of the lead bird while maintaining position slightly above the leader. The lead bird turned in a direction away from the lateral position of the following bird 65% of the time on average. Tandem flights vary widely in instantaneous speed (1.0 to 15.6 m s(-1)) and duration (0.72 to 4.71 s), and no single tracking strategy appeared to explain the course taken by the following bird. © 2014. Published by The Company of Biologists Ltd.

Flight thresholds and seasonal variations in flight activity of the light-brown apple moth, Epiphyas postvittana (Walk.) (Tortricidae), in Victoria, Australia.

PubMed

Danthanarayana, W

1976-12-01

The flight activity of Epiphyas postvittana was studied at two sites near Melbourne with the aid of suction traps, over a period of 4 years. Maximum numbers were found to fly during the period September to March with peak activity coinciding with the emergence of winter, spring and summer generation moths. E. postivittana is predominantly a nocturnal flier with maximum activity around 20.00-24.00 h. The lower temperature threshold of flight was 8-11°C. The upper temperature threshold varied from 20-21°C, 24-25°C and 27-28°C for the winter, spring and summer generation moths respectively. Flight was highly influenced by the prevailing wind. The lower wind speed threshold was 0.5-0.8 m -s and the upper wind speed threshold was 2.6-2.7 m -s . The relationship between wind speed and the amount of flight was non-linear, with the frequency of flights decreasing sharply with increasing wind speed. No flights occurred at wind speeds greater than 2.8 m -s . Variation in relative humidity had no influence on flight, but lack of rain favoured flight. The amount of flight activity and the amount of rainfall were negatively correlated; flights did not occur when the daily precipitation exceeded 32.5 mm, and with a precipitation exceeding 39 mm no flights could be expected. The value of these findings to pest control programmes is discussed.

Preliminary Tests in the NACA Tank to Investigate the Fundamental Characteristics of Hydrofoils

NASA Technical Reports Server (NTRS)

Ward, Kenneth E.; Land, Norman S.

1940-01-01

This preliminary investigation was made to study the hydrodynamic properties and general behavior of simple hydrofoils. Six 5- by 30-inch plain, rectangular hydrofoils were tested in the NACA tank at various speeds, angles of attack and depths below the water surface. Two of the hydrofoils had sections representing the sections of commonly used airfoils, one had a section similar to one developed Guidoni for use with hydrofoil-equipped seaplane floats, and three had sections designed to have constant chordwise pressure distributions at given values of the lift coefficient for the purpose of delaying the speed at which cavitation begins. The experimental results are presented as curves of the lift and drag coefficients plotted against speed for the various angles of attack and depths for which the hydrofoils were tested. A number of derived curves are included for the purpose of better comparing the characteristics of the hydrofoils and to show the effects of depth. Several representative photographs show the development of cavitation on the the upper surface of the hydrofoils. The results indicate that properly designed hydrofoil sections will have excellent characteristics and that the speed at which cavitation occurs may be delayed to an appreciable extent by the use of suitable sections.

Preliminary Results of Altitude-Wind-Tunnel Investigation of X24C-4B Turbojet Engine. I - Pressure and Temperature Distributions

NASA Technical Reports Server (NTRS)

Prince, William R.; Hawkins, W. Kent

1947-01-01

Pressures and temperatures throughout the X24C-4B turbojet engine are presented in both tabular and graphical forms to show the effect of altitude, flight Mach number, and engine speed on the internal operation of the engine. These data were obtained in the NACA Cleveland altitude wind tunnel at simulated altitudes from 5000 to 45,000 feet, simulated flight Mach numbers from 0.25 to 1.08, and engine speeds from 4000 to 12,500 rpm. Location and detail drawings of the instrumentation installed at seven survey stations in the engine are shown. Application of generalization factors to pressures and temperatures at each measuring station for the range of altitudes investigated showed that the data did not generalize above an altitude of 25,000 feet. Total-pressure distribution at the compressor outlet varied only with change in engine speed. At altitudes above 35,000 feet and engine speeds above 11,000 rpm, the peak temperature at the turbine-outlet annulus moved inward toward the root of the blade, which is undesirable from blade-stress considerations. The temperature levels at the turbine outlet and the exhaust-nozzle outlet were lowered as the Mach number was increased. The static-pressure measurements obtained at each stator stage of the compressor showed a pressure drop through the inlet guide vanes and the first-stage rotor at high engine speeds. The average values measured by the manufacturer's instrumentation werein close agreement with the average values obtained with NACA instrumentation.

High Speed Stability and Control Characteristics of a 0.17-Scale Model of the McDonnell XF2H-1 Airplane (TED No. NACA DE 318)

NASA Technical Reports Server (NTRS)

Axelson, John A.; Emerson, Horace F.

1949-01-01

High-speed wind-tunnel tests were conducted of two versions of a 0.17-scale model of the McDonnell XF2H-1 airplane to ascertain the high-speed stability and control characteristics and to study means for raising the high-speed buffet limit of the airplane, The results for the revised model, employing a thinner wing and tail than the original model, revealed a mild diving tendency from 0.75 to 0.80 Mach number, followed by a marked climbing tendency from 0.80 to 0.875 Mach number. The high-speed climbing tendency was caused principally by the pitching-moment characteristics of the wing. At 0.875 Mach number the results for the revised model indicated stick-fixed directional instability over a limited range of yaw angles, apparently caused by separated flow over the vertical tail. The test results indicate that the high-speed buffet limit of the airplane can probably be raised by reducing the thickness and changing the relative location of the horizontal and vertical tails, and by revising the inner portion of the wing to have a lower thickness-to-chord ratio and reduced trailing-edge angle. The addition of the wing-tip tanks to the revised model resulted in a forward shift in the neutral point below 0.82 Mach number.

Saturn Apollo Program

NASA Image and Video Library

1969-01-09

Neil Armstrong, donned in his space suit, poses for his official Apollo 11 portrait. Armstrong began his flight career as a naval aviator. He flew 78 combat missions during the Korean War. Armstrong joined the NASA predecessor, NACA (National Advisory Committee for Aeronautics), as a research pilot at the Lewis Laboratory in Cleveland and later transferred to the NACA High Speed Flight Station at Edwards AFB, California. He was a project pilot on many pioneering high speed aircraft, including the 4,000 mph X-15. He has flown over 200 different models of aircraft, including jets, rockets, helicopters, and gliders. In 1962, Armstrong was transferred to astronaut status. He served as command pilot for the Gemini 8 mission, launched March 16, 1966, and performed the first successful docking of two vehicles in space. In 1969, Armstrong was commander of Apollo 11, the first manned lunar landing mission, and gained the distinction of being the first man to land a craft on the Moon and the first man to step on its surface. Armstrong subsequently held the position of Deputy Associate Administrator for Aeronautics, NASA Headquarters Office of Advanced Research and Technology, from 1970 to 1971. He resigned from NASA in 1971.

Official Portrait of Astronaut Neil Armstrong

NASA Technical Reports Server (NTRS)

1969-01-01

Neil Armstrong, donned in his space suit, poses for his official Apollo 11 portrait. Armstrong began his flight career as a naval aviator. He flew 78 combat missions during the Korean War. Armstrong joined the NASA predecessor, NACA (National Advisory Committee for Aeronautics), as a research pilot at the Lewis Laboratory in Cleveland and later transferred to the NACA High Speed Flight Station at Edwards AFB, California. He was a project pilot on many pioneering high speed aircraft, including the 4,000 mph X-15. He has flown over 200 different models of aircraft, including jets, rockets, helicopters, and gliders. In 1962, Armstrong was transferred to astronaut status. He served as command pilot for the Gemini 8 mission, launched March 16, 1966, and performed the first successful docking of two vehicles in space. In 1969, Armstrong was commander of Apollo 11, the first manned lunar landing mission, and gained the distinction of being the first man to land a craft on the Moon and the first man to step on its surface. Armstrong subsequently held the position of Deputy Associate Administrator for Aeronautics, NASA Headquarters Office of Advanced Research and Technology, from 1970 to 1971. He resigned from NASA in 1971.

The influence of flight speed on the ranging performance of bats using frequency modulated echolocation pulses

NASA Astrophysics Data System (ADS)

Boonman, Arjan M.; Parsons, Stuart; Jones, Gareth

2003-01-01

Many species of bat use ultrasonic frequency modulated (FM) pulses to measure the distance to objects by timing the emission and reception of each pulse. Echolocation is mainly used in flight. Since the flight speed of bats often exceeds 1% of the speed of sound, Doppler effects will lead to compression of the time between emission and reception as well as an elevation of the echo frequencies, resulting in a distortion of the perceived range. This paper describes the consequences of these Doppler effects on the ranging performance of bats using different pulse designs. The consequences of Doppler effects on ranging performance described in this paper assume bats to have a very accurate ranging resolution, which is feasible with a filterbank receiver. By modeling two receiver types, it was first established that the effects of Doppler compression are virtually independent of the receiver type. Then, used a cross-correlation model was used to investigate the effect of flight speed on Doppler tolerance and range-Doppler coupling separately. This paper further shows how pulse duration, bandwidth, function type, and harmonics influence Doppler tolerance and range-Doppler coupling. The influence of each signal parameter is illustrated using calls of several bat species. It is argued that range-Doppler coupling is a significant source of error in bat echolocation, and various strategies bats could employ to deal with this problem, including the use of range rate information are discussed.

NACA Conference on Aircraft Loads, Structures, and Flutter

NASA Technical Reports Server (NTRS)

1957-01-01

This document contains reproductions of technical papers on some of the most recent research results on aircraft loads, flutter, and structures from the NACA laboratories. These papers were presented by members of the staff of the NACA laboratories at the Conference held at the Langley Aeronautical Laboratory March 5, 6, and 7, 1957. The primary purpose of this Conference was to convey to contractors of the military services and others concerned with the design of aircraft these recent research results and to provide those attending an opportunity to discuss the results. The papers in this document are in the same form in which they were presented at the Conference in order to facilitate their prompt distribution. The original presentation and this record are considered as complementary to, rather than as substitutes for, the Committee?s more complete and formal reports. Accordingly, if information from this document is utilized it is requested that this document not be listed as a reference. Individual reports dealing with most of the information presented at the Conference will subsequently be published by NACA and will therefore be suitable as reference material.

Verification of a ground-based method for simulating high-altitude, supersonic flight conditions

NASA Astrophysics Data System (ADS)

Zhou, Xuewen; Xu, Jian; Lv, Shuiyan

Ground-based methods for accurately representing high-altitude, high-speed flight conditions have been an important research topic in the aerospace field. Based on an analysis of the requirements for high-altitude supersonic flight tests, a ground-based test bed was designed combining Laval nozzle, which is often found in wind tunnels, with a rocket sled system. Sled tests were used to verify the performance of the test bed. The test results indicated that the test bed produced a uniform-flow field with a static pressure and density equivalent to atmospheric conditions at an altitude of 13-15km and at a flow velocity of approximately M 2.4. This test method has the advantages of accuracy, fewer experimental limitations, and reusability.

F-100A on lakebed

NASA Technical Reports Server (NTRS)

1959-01-01

North American F-100A (52-5778) Super Sabre sitting on the Rogers dry lakebed, 1959. Pitch-up could be overcome by several 'fixes', but the problems and cost outweighed the potential benefits. The obvious conclusion from NACA High-Speed Flight Station testing as to the desirability of the low horizontal tail surface led to that configuration's becoming standard on the first-generation supersonic sweptwing fighters such as the F-100 Super Sabre.

Passive control of rotorcraft high-speed impulsive noise

NASA Astrophysics Data System (ADS)

Szulc, O.; Doerffer, P.; Tejero, F.

2016-10-01

A strong, normal shock wave, terminating a local supersonic area located at the tip of a helicopter blade, not only limits the aerodynamic performance, but also constitutes an origin of the High-Speed Impulsive (HSI) noise. The application of a passive control device (a shallow cavity covered by a perforated plate) just beneath the interaction region weakens the compression level, thus reducing the main source of the HSI noise. The numerical investigation based on the URANS approach and Bohning/Doerffer (BD) transpiration law (SPARC code) confirms a large potential of the new method. Two exemplary implementations, adapted to model helicopter rotors tested at NASA Ames facility in transonic conditions: Caradonna-Tung (lifting, transonic hover) and Caradonna-Laub-Tung (non-lifting, high-speed forward flight), demonstrate the possible gains in terms of the reduction of acoustic pressure fluctuations in the near-field of the blade tip. The CFD results are validated against the experimental data obtained for the reference configurations (no control), while the analysis of the passive control arrangement is based on a purely numerical research. The normal shock wave is effectively eliminated by the wall ventilation exerting a positive impact on the generated level of the HSI noise.

Six Decades of Flight Research: An Annotated Bibliography of Technical Publications of NASA Dryden Flight Research Center, 1946-2006

NASA Technical Reports Server (NTRS)

Fisher, David F.

2007-01-01

Titles, authors, report numbers, and abstracts are given for nearly 2900 unclassified and unrestricted technical reports and papers published from September 1946 to December 2006 by the NASA Dryden Flight Research Center and its predecessor organizations. These technical reports and papers describe and give the results of 60 years of flight research performed by the NACA and NASA, from the X-1 and other early X-airplanes, to the X-15, Space Shuttle, X-29 Forward Swept Wing, X-31, and X-43 aircraft. Some of the other research airplanes tested were the D-558, phase 1 and 2; M-2, HL-10 and X-24 lifting bodies; Digital Fly-By-Wire and Supercritical Wing F-8; XB-70; YF-12; AFTI F-111 TACT and MAW; F-15 HiDEC; F-18 High Alpha Research Vehicle, F-18 Systems Research Aircraft and the NASA Landing Systems Research aircraft. The citations of reports and papers are listed in chronological order, with author and aircraft indices. In addition, in the appendices, citations of 270 contractor reports, more than 200 UCLA Flight System Research Center reports, nearly 200 Tech Briefs, 30 Dryden Historical Publications, and over 30 videotapes are included.

Two-and three-dimensional unsteady lift problems in high-speed flight

NASA Technical Reports Server (NTRS)

Lomax, Harvard; Heaslet, Max A; Fuller, Franklyn B; Sluder, Loma

1952-01-01

The problem of transient lift on two- and three-dimensional wings flying at high speeds is discussed as a boundary-value problem for the classical wave equation. Kirchoff's formula is applied so that the analysis is reduced, just as in the steady state, to an investigation of sources and doublets. The applications include the evaluation of indicial lift and pitching-moment curves for two-dimensional sinking and pitching wings flying at Mach numbers equal to 0, 0.8, 1.0, 1.2 and 2.0. Results for the sinking case are also given for a Mach number of 0.5. In addition, the indicial functions for supersonic-edged triangular wings in both forward and reverse flow are presented and compared with the two-dimensional values.

Historical perspectives on thermostructural research at the NACA Langley Aeronautical Laboratory from 1948 to 1958

NASA Technical Reports Server (NTRS)

Heldenfels, R. R.

1982-01-01

Some of the early research on structural problems produced by aerodynamic heating, conducted at the Langley Aeronautical Laboratory of the National Advisory Committee for Aeronautics from 1948 to 1958 is described. That was the last decade of the NACA; in 1958 NACA became the nucleus of NASA. The NACA initially contracted for research but was aware that a well-equipped and suitably staffed laboratory was required to fulfill its obligations. Langley was established in 1920; the other listed were added during the NACA expansion in the World War II years. Some specific research activities are described, starting with calculation of the temperature of the structure.

Historical perspectives on thermostructural research at the NACA Langley Aeronautical Laboratory from 1948 to 1958

NASA Astrophysics Data System (ADS)

Heldenfels, R. R.

Some of the early research on structural problems produced by aerodynamic heating, conducted at the Langley Aeronautical Laboratory of the National Advisory Committee for Aeronautics from 1948 to 1958 is described. That was the last decade of the NACA; in 1958 NACA became the nucleus of NASA. The NACA initially contracted for research but was aware that a well-equipped and suitably staffed laboratory was required to fulfill its obligations. Langley was established in 1920; the other listed were added during the NACA expansion in the World War II years. Some specific research activities are described, starting with calculation of the temperature of the structure.

F-86 Sabre on lakebed, front view

NASA Technical Reports Server (NTRS)

1954-01-01

With the NACA High-Speed Flight Station (HSFS) main building (4800) in the background the North American F-86F (Serial #52-5426) Sabre sits on the Rogers Dry lakebed just off the NACA ramp in 1954. This was soon after the National Advisory Committee for Aeronautics unit moved from South Base at Edwards Air Force Base to the new building that still houses the NASA Dryden Flight Research Center, successor to the HSFS. The F-86F performed both pitch-up research and duties as a chase aircraft for the D-558-2. Its stay at the HSFS was brief. It arrived on June 23, 1954, and left on September 10 the same year. The F-86 had a 35 degree sweptwing and a wing span of 37 feet 1 inch with a General Electric J47-GE engine. It was the first U.S. sweptwing fighter and saw extensive action in the Korean War. It could slightly exceed Mach 1 in a dive.

Laminar-flow flight experiments

NASA Technical Reports Server (NTRS)

Wagner, Richard D.; Maddalon, Dal V.; Bartlett, D. W.; Collier, F. S., Jr.; Braslow, A. L.

1989-01-01

The flight testing conducted over the past 10 years in the NASA laminar-flow control (LFC) will be reviewed. The LFC program was directed towards the most challenging technology application, the high supersonic speed transport. To place these recent experiences in perspective, earlier important flight tests will first be reviewed to recall the lessons learned at that time.

Flight measurement and analysis of AAFE RADSCAT wind speed signature of the ocean

NASA Technical Reports Server (NTRS)

Schroeder, L. C.; Jones, W. L.; Schaffner, P. R.; Mitchell, J. L.

1984-01-01

The advanced aerospace flight experiment radiometer scatterometer (AAFE RADSCAT) which was developed as a research tool to evaluate the use of microwave frequency remote sensors to provide wind speed information at the ocean surface is discussed. The AAFE RADSCAT helped establish the feasibility of the satellite scatterometer for measuring both wind speed and direction. The most important function of the AAFE RADSCAT was to provide a data base of ocean normalized radar cross section (NRCS) measurements as a function of surface wind vector at 13.9 GHz. The NRCS measurements over a wide parametric range of incidence angles, azimuth angles, and winds were obtained in a series of RADSCAT aircraft missions. The obtained data base was used to model the relationship between k sub u band radar signature and ocean surface wind vector. The models developed therefrom are compared with those used for inversion of the SEASAT-A satellite scatterometer (SASS) radar measurements to wind speeds.

3-D high-speed imaging of volcanic bomb trajectory in basaltic explosive eruptions

USGS Publications Warehouse

Gaudin, D.; Taddeucci, J; Houghton, Bruce F.; Orr, Tim R.; Andronico, D.; Del Bello, E.; Kueppers, U.; Ricci, T.; Scarlato, P.

2016-01-01

Imaging, in general, and high speed imaging in particular are important emerging tools for the study of explosive volcanic eruptions. However, traditional 2-D video observations cannot measure volcanic ejecta motion toward and away from the camera, strongly hindering our capability to fully determine crucial hazard-related parameters such as explosion directionality and pyroclasts' absolute velocity. In this paper, we use up to three synchronized high-speed cameras to reconstruct pyroclasts trajectories in three dimensions. Classical stereographic techniques are adapted to overcome the difficult observation conditions of active volcanic vents, including the large number of overlapping pyroclasts which may change shape in flight, variable lighting and clouding conditions, and lack of direct access to the target. In particular, we use a laser rangefinder to measure the geometry of the filming setup and manually track pyroclasts on the videos. This method reduces uncertainties to 10° in azimuth and dip angle of the pyroclasts, and down to 20% in the absolute velocity estimation. We demonstrate the potential of this approach by three examples: the development of an explosion at Stromboli, a bubble burst at Halema'uma'u lava lake, and an in-flight collision between two bombs at Stromboli.

In-Flight Boundary-Layer Transition of a Large Flat Plate at Supersonic Speeds

NASA Technical Reports Server (NTRS)

Banks, D. W.; Frederick, M. A.; Tracy, R. R.; Matisheck, J. R.; Vanecek, N. D.

2012-01-01

A flight experiment was conducted to investigate the pressure distribution, local-flow conditions, and boundary-layer transition characteristics on a large flat plate in flight at supersonic speeds up to Mach 2.00. The tests used a NASA testbed aircraft with a bottom centerline mounted test fixture. The primary objective of the test was to characterize the local flow field in preparation for future tests of a high Reynolds number natural laminar flow test article. A second objective was to determine the boundary-layer transition characteristics on the flat plate and the effectiveness of using a simplified surface coating. Boundary-layer transition was captured in both analog and digital formats using an onboard infrared imaging system. Surface pressures were measured on the surface of the flat plate. Flow field measurements near the leading edge of the test fixture revealed the local flow characteristics including downwash, sidewash, and local Mach number. Results also indicated that the simplified surface coating did not provide sufficient insulation from the metallic structure, which likely had a substantial effect on boundary-layer transition compared with that of an adiabatic surface. Cold wall conditions were predominant during the acceleration to maximum Mach number, and warm wall conditions were evident during the subsequent deceleration.

NACA 0015 wing pressure and trailing vortex measurements

NASA Technical Reports Server (NTRS)

Mcalister, K. W.; Takahashi, R. K.

1991-01-01

A NACA 0015 semispan wing was placed in a low-speed wind tunnel, and measurements were made of the pressure on the upper and lower surface of the wing and of velocity across the vortex trailing downstream from the tip of the wing. Pressure data were obtained for both 2-D and 3-D configurations. These data feature a detailed comparison between wing tips with square and round lateral edges. A two-component laser velocimeter was used to measure velocity profiles across the vortex at numerous stations behind the wing and for various combinations of conditions. These conditions include three aspect ratios, three chord lengths, a square- and a round lateral-tip, presence or absence of a boundary-layer trip, and three image plane positions located opposite the wing tip. Both pressure and velocity measurements were made for the angles of attack 4 deg less than or equal to alpha less than or equal to 12 deg and for Reynolds numbers 1 x 10(exp 6) less than or equal to Re less than or equal to 3 x 10(exp 6).

Airfoil shape for flight at subsonic speeds

DOEpatents

Whitcomb, Richard T.

1976-01-01

An airfoil having an upper surface shaped to control flow accelerations and pressure distribution over the upper surface and to prevent separation of the boundary layer due to shock wave formulation at high subsonic speeds well above the critical Mach number. A highly cambered trailing edge section improves overall airfoil lifting efficiency.

NSEG, a segmented mission analysis program for low and high speed aircraft. Volume 1: Theoretical development

NASA Technical Reports Server (NTRS)

Hague, D. S.; Rozendaal, H. L.

1977-01-01

A rapid mission analysis code based on the use of approximate flight path equations of motion is presented. Equation form varies with the segment type, for example, accelerations, climbs, cruises, descents, and decelerations. Realistic and detailed characteristics were specified in tabular form. The code also contains extensive flight envelope performance mapping capabilities. Approximate take off and landing analyses were performed. At high speeds, centrifugal lift effects were accounted for. Extensive turbojet and ramjet engine scaling procedures were incorporated in the code.

X-1A on lakebed

NASA Technical Reports Server (NTRS)

1955-01-01

The Bell Aircraft Corporation X-1A (48-1384) is photographed in 1955 sitting on the Rogers Dry Lakebed at Edwards, California. This view of the right side of the aircraft shows a middle section that contrasts quite distinctively with the over-all white paint scheme of the X-1A during its NACA High-Speed Flight Research Station tenure. The extreme cold of the liquid oxygen used as a propellant (along with alcohol) and its deleterious affect on paint dictated that the fuselage area next to the tank be left unpainted. The X-1A arrived at Edwards Air Force Base, California, on January 7, 1953. Bell test pilot Jean 'Skip' Ziegler made six test flights between 14 February and 25 April 1953. Air Force test pilots Maj. Charles 'Chuck' Yeager and Maj. Arthur 'Kit' Murray made 18 flights between 21 November 1953 and 26 August 1954. NACA test pilot Joe Walker made one successful flight on 20 July 1955. During a second flight attempt on 8 August 1955, an explosion damaged the aircraft shortly before launch. Walker climbed back up into the JTB-29A mothership, and the X-1A was jettisoned over the Edwards AFB bombing range.

DC-10 winglet flight evaluation

NASA Technical Reports Server (NTRS)

1983-01-01

The results of a flight evaluation of winglets on a DC-10 Series 10 aircraft are presented. For sensitive areas of comparison, effects of winglets were determined back to back with and without winglets. Basic and reduced span winglet configurations were tested. After initial encounter with low speed buffet, a number of acceptable configurations were developed. For maximum drag reduction at both cruise and low speeds, lower winglets were required, having leading edge devices on upper and lower winglets for the latter regime. The cruise benefits were enhanced by adding outboard aileron droop to the reduced span winglet aircraft. Winglets had no significant impact on stall speeds, high speed buffet boundary, and stability and control characteristics. Flutter test results agreed with predictions and ground vibration data. Flight loads measurement also agreed with predictions.

Model helicopter rotor high-speed impulsive noise: Measured acoustics and blade pressures

NASA Technical Reports Server (NTRS)

Boxwell, D. A.; Schmitz, F. H.; Splettstoesser, W. R.; Schultz, K. J.

1983-01-01

A 1/17-scale research model of the AH-1 series helicopter main rotor was tested. Model-rotor acoustic and simultaneous blade pressure data were recorded at high speeds where full-scale helicopter high-speed impulsive noise levels are known to be dominant. Model-rotor measurements of the peak acoustic pressure levels, waveform shapes, and directively patterns are directly compared with full-scale investigations, using an equivalent in-flight technique. Model acoustic data are shown to scale remarkably well in shape and in amplitude with full-scale results. Model rotor-blade pressures are presented for rotor operating conditions both with and without shock-like discontinuities in the radiated acoustic waveform. Acoustically, both model and full-scale measurements support current evidence that above certain high subsonic advancing-tip Mach numbers, local shock waves that exist on the rotor blades ""delocalize'' and radiate to the acoustic far-field.

Flight Research Building at the Aircraft Engine Research Laboratory

NASA Image and Video Library

1942-09-21

The Flight Research Building at the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory is a 272- by 150-foot hangar with an internal height up to 90 feet. The hangar’s massive 37.5-foot-tall and 250-foot-long doors can be opened in sections to suit different size aircraft. The hangar has sheltered a diverse fleet of aircraft over the decades. These have ranged from World War II bombers to Cessna trainers and from supersonic fighter jets to a DC–9 airliner. At the time of this September 1942 photograph, however, the hangar was being used as an office building during the construction of the laboratory. In December of 1941, the Flight Research Building became the lab’s first functional building. Temporary offices were built inside the structure to house the staff while the other buildings were completed. The hangar offices were used for an entire year before being removed in early 1943. It was only then that the laboratory acquired its first aircraft, pilots and flight mechanics. The temporary one-story offices can be seen in this photograph inside the large sliding doors. Also note the vertical lift gate below the NACA logo. The gate was installed so that the tails of larger aircraft could pass into the hangar. The white Farm House that served as the Administration Building during construction can be seen in the distance to the left of the hangar.

Aerodynamic data banks for Clark-Y, NACA 4-digit and NACA 16-series airfoil families

NASA Technical Reports Server (NTRS)

Korkan, K. D.; Camba, J., III; Morris, P. M.

1986-01-01

With the renewed interest in propellers as means of obtaining thrust and fuel efficiency in addition to the increased utilization of the computer, a significant amount of progress was made in the development of theoretical models to predict the performance of propeller systems. Inherent in the majority of the theoretical performance models to date is the need for airfoil data banks which provide lift, drag, and moment coefficient values as a function of Mach number, angle-of-attack, maximum thickness to chord ratio, and Reynolds number. Realizing the need for such data, a study was initiated to provide airfoil data banks for three commonly used airfoil families in propeller design and analysis. The families chosen consisted of the Clark-Y, NACA 16 series, and NACA 4 digit series airfoils. The various component of each computer code, the source of the data used to create the airfoil data bank, the limitations of each data bank, program listing, and a sample case with its associated input-output are described. Each airfoil data bank computer code was written to be used on the Amdahl Computer system, which is IBM compatible and uses Fortran.

Control for small-speed lateral flight in a model insect.

PubMed

Zhang, Yan Lai; Sun, Mao

2011-09-01

Controls required for small-speed lateral flight of a model insect were studied using techniques based on the linear theories of stability and control (the stability and control derivatives were computed by the method of computational fluid dynamics). The main results are as follows. (1) Two steady-state lateral motions can exist: one is a horizontal side translation with the body rolling to the same side of the translation by a small angle, and the other is a constant-rate yaw rotation (rotation about the vertical axis). (2) The side translation requires an anti-symmetrical change in the stroke amplitudes of the contralateral wings, and/or an anti-symmetrical change in the angles of attack of the contralateral wings, with the down- and upstroke angles of attack of a wing having equal change. The constant-rate yaw rotation requires an anti-symmetrical change in the angles of attack of the contralateral wings, with the down- and upstroke angles of attack of a wing having differential change. (3) For the control of the horizontal side translation, control input required for the steady-state motion has an opposite sign to that needed for initiating the motion. For example, to have a steady-state left side-translation, the insect needs to increase the stroke amplitude of the left wing and decrease that of the right wing to maintain the steady-state flight, but it needs an opposite change in stroke amplitude (decreasing the stroke amplitude of the left wing and increasing that of the right wing) to enter the flight.

Identification of high-speed rail ballast flight risk factors and risk mitigation strategies - final report.

DOT National Transportation Integrated Search

2015-04-01

The phenomenon of flying ballast is well-documented in high-speed rail operations. Displaced ballast particles from the track bed : may cause damage to rolling stock as well as the track infrastructure, and wayside structures close to the right of wa...

Genetic markers that influence feed efficiency phenotypes also affect cattle temperament as measured by flight speed

USDA-ARS?s Scientific Manuscript database

The measure of flight speed for cattle has been shown to be a predictive indicator of temperament and has also been associated with feed efficiency phenotypes, thus, genetic markers associated with both traits may assist with the selection of animals with calmer disposition and economic value. Chrom...

Butterflies' wings deformations using high speed digital holographic interferometry

NASA Astrophysics Data System (ADS)

Mendoza Santoyo, Fernando; Aguayo, Daniel D.; de La Torre-Ibarra, Manuel H.; Salas-Araiza, Manuel D.

2011-08-01

A variety of efforts in different scientific disciplines have tried to mimic the insect's in-flight complex system. The gained knowledge has been applied to improve the performance of different flying artifacts. In this research report it is presented a displacement measurement on butterflies' wings using the optical noninvasive Digital Holographic Interferometry technique with out of plane sensitivity, using a high power cw laser and a high speed CMOS camera to record the unrepeatable displacement movements on these organic tissues. A series of digital holographic interferograms were recorded and the experimental results for several butterflies during flapping events. The relative unwrapped phase maps micro-displacements over the whole wing surface are shown in a wire-mesh representation. The difference between flying modes is remarkably depicted among them.

ARC-1969-A-16712

NASA Image and Video Library

1951-12-06

Date: Dec 6, 1951 NACA Photographer North American YF-93 with submerged divergent-wall engine-air inlet. Maximum high-speed capability of Mach 1.03 was obtained with afterbrner on. Tests were conducted to compare high-speed performance of the YF-93 NACA-139 airplane with different inlet configurations. (Mar 1953)

Interior noise considerations for advanced high-speed turboprop aircraft

NASA Technical Reports Server (NTRS)

Mixson, J. S.; Farassat, F.; Leatherwood, J. D.; Prydz, R.; Revell, J. D.

1982-01-01

This paper describes recent research on noise generated by high-speed propellers, on noise transmission through acoustically treated aircraft sidewalls and on subjective response to simulated turboprop noise. Propeller noise discussion focuses on theoretical prediction methods for complex blade shapes designed for low noise at Mach = 0.8 flight and on comparisons with experimental test results. Noise transmission experiments using a 168 cm. diameter aircraft fuselage model and scaled heavy-double-wall treatments indicate that the treatments perform well and that the predictions are usually conservative. Studies of subjective comfort response in an anechoic environment are described for noise signatures having combinations of broadband and propeller-type tone components.

In-Flight Boundary-Layer Transition on a Large Flat Plate at Supersonic Speeds

NASA Technical Reports Server (NTRS)

Banks, Daniel W.; Fredericks, Michael Alan; Tracy, Richard R.; Matisheck, Jason R.; Vanecek, Neal D.

2012-01-01

A flight experiment was conducted to investigate the pressure distribution, local flow conditions, and boundary-layer transition characteristics on a large flat plate in flight at supersonic speeds up to Mach 2.0. The primary objective of the test was to characterize the local flow field in preparation for future tests of a high Reynolds number natural laminar flow test article. The tests used a F-15B testbed aircraft with a bottom centerline mounted test fixture. A second objective was to determine the boundary-layer transition characteristics on the flat plate and the effectiveness of using a simplified surface coating for future laminar flow flight tests employing infrared thermography. Boundary-layer transition was captured using an onboard infrared imaging system. The infrared imagery was captured in both analog and digital formats. Surface pressures were measured with electronically scanned pressure modules connected to 60 surface-mounted pressure orifices. The local flow field was measured with five 5-hole conical probes mounted near the leading edge of the test fixture. Flow field measurements revealed the local flow characteristics including downwash, sidewash, and local Mach number. Results also indicated that the simplified surface coating did not provide sufficient insulation from the metallic structure, which likely had a substantial effect on boundary-layer transition compared with that of an adiabatic surface. Cold wall conditions were predominant during the acceleration to maximum Mach number, and warm wall conditions were evident during the subsequent deceleration. The infrared imaging system was able to capture shock wave impingement on the surface of the flat plate in addition to indicating laminar-to-turbulent boundary-layer transition.

[Separation and identification of bovine lactoferricin by high performance liquid chromatography-matrix-assisted laser desorption/ionization time of flight/ time of flight mass spectrometry].

PubMed

An, Meichen; Liu, Ning

2010-02-01

A high performance liquid chromatography-matrix-assisted laser desorption/ionization time of flight/time of flight mass spectrometry (HPLC-MALDI-TOF/TOF MS) method was developed for the separation and identification of bovine lactoferricin (LfcinB). Bovine lactoferrin was hydrolyzed by pepsin and then separated by ion exchange chromatography and reversed-phase liquid chromatography (RP-LC). The antibacterial activities of the fractions from RP-LC separation were determined and the protein concentration of the fraction with the highest activity was measured, whose sequence was indentified by MALDI-TOF/TOF MS. The relative molecular mass of LfcinB was 3 124.89 and the protein concentration was 18.20 microg/mL. The method of producing LfcinB proposed in this study has fast speed, high accuracy and high resolution.

E56-2607

NASA Image and Video Library

1956-10-08

Famed astronaut Neil A. Armstrong, the first man to set foot on the moon during the historic Apollo 11 space mission in July 1969, served for seven years as a research pilot at the NACA-NASA High-Speed Flight Station, now the Dryden Flight Research Center, at Edwards, California, before he entered the space program. Armstrong joined the National Advisory Committee for Aeronautics (NACA) at the Lewis Flight Propulsion Laboratory (later NASA's Lewis Research Center, Cleveland, Ohio, and today the Glenn Research Center) in 1955. Later that year, he transferred to the High-Speed Flight Station at Edwards as an aeronautical research scientist and then as a pilot, a position he held until becoming an astronaut in 1962. He was one of nine NASA astronauts in the second class to be chosen. As a research pilot Armstrong served as project pilot on the F-100A and F-100C aircraft, F-101, and the F-104A. He also flew the X-1B, X-5, F-105, F-106, B-47, KC-135, and Paresev. He left Dryden with a total of over 2450 flying hours. He was a member of the USAF-NASA Dyna-Soar Pilot Consultant Group before the Dyna-Soar project was cancelled, and studied X-20 Dyna-Soar approaches and abort maneuvers through use of the F-102A and F5D jet aircraft. Armstrong was actively engaged in both piloting and engineering aspects of the X-15 program from its inception. He completed the first flight in the aircraft equipped with a new flow-direction sensor (ball nose) and the initial flight in an X-15 equipped with a self-adaptive flight control system. He worked closely with designers and engineers in development of the adaptive system, and made seven flights in the rocket plane from December 1960 until July 1962. During those fights he reached a peak altitude of 207,500 feet in the X-15-3, and a speed of 3,989 mph (Mach 5.74) in the X-15-1. Armstrong has a total of 8 days and 14 hours in space, including 2 hours and 48 minutes walking on the Moon. In March 1966 he was commander of the Gemini 8 or

Shuttle Rudder/Speed Brake Power Drive Unit (PDU) Gear Scuffing Tests With Flight Gears

NASA Technical Reports Server (NTRS)

Proctor, Margaret P.; Oswald, Fred B.; Krants, Timothy L.

2005-01-01

Scuffing-like damage has been found on the tooth surfaces of gears 5 and 6 of the NASA space shuttle rudder/speed brake power drive unit (PDU) number 2 after the occurrence of a transient back-driving event in flight. Tests were conducted using a pair of unused spare flight gears in a bench test at operating conditions up to 2866 rpm and 1144 in.-lb at the input ring gear and 14,000 rpm and 234 in.-lb at the output pinion gear, corresponding to a power level of 52 hp. This test condition exceeds the maximum estimated conditions expected in a backdriving event thought to produce the scuffing damage. Some wear marks were produced, but they were much less severe than the scuffing damaged produced during shuttle flight. Failure to produce scuff damage like that found on the shuttle may be due to geometrical variations between the scuffed gears and the gears tested herein, more severe operating conditions during the flight that produced the scuff than estimated, the order of the test procedures, the use of new hydraulic oil, differences between the dynamic response of the flight gearbox and the bench-test gearbox, or a combination of these. This report documents the test gears, apparatus, and procedures, summarizes the test results, and includes a discussion of the findings, conclusions, and recommendations.

NASA's High Speed Research Program - An introduction and status report

NASA Technical Reports Server (NTRS)

Wesoky, Howard L.; Prather, Michael J.; Kayten, Gerald G.

1990-01-01

NASA's High Speed Research Program (HSRP) gives attention to the potential environmental effects of a next-generation SST in three areas of concern: atmospheric pollution, airport community noise, and sonic boom. Research has accordingly been undertaken in such fields as the validation of ozone depletion predictions, the feasibility a 90-percent NO(x) emissions reduction to minimize ozone-layer impacts, economically viable compliance with FAR 36 Stage 3 airport community noise levels, and the comparative advantages of efficient subsonic flight over land masses or low-sonic-boom-optimized configurations. Interim HSRP milestones for 1991 and 1992 are noted.

Propulsion system-flight control integration-flight evaluation and technology transition

NASA Technical Reports Server (NTRS)

Burcham, Frank W., Jr.; Gilyard, Glenn B.; Myers, Lawrence P.

1990-01-01

Integration of propulsion and flight control systems and their optimization offering significant performance improvement are assessed. In particular, research programs conducted by NASA on flight control systems and propulsion system-flight control interactions on the YF-12 and F-15 aircraft are addressed; these programs have demonstrated increased thrust, reduced fuel consumption, increased engine life, and improved aircraft performance. Focus is placed on altitude control, speed-Mach control, integrated controller design, as well as flight control systems and digital electronic engine control. A highly integrated digital electronic control program is analyzed and compared with a performance seeking control program. It is shown that the flight evaluation and demonstration of these technologies have been a key part in the transition of the concepts to production and operational use on a timely basis.

Some aerodynamic discoveries and related NACA/NASA research programs following World War 2

NASA Technical Reports Server (NTRS)

Spearman, M. L.

1984-01-01

The World War 2 time period ushered in a new era in aeronautical research and development. The air conflict during the war highlighted the need of aircraft with agility, high speed, long range, large payload capability, and in addition, introduced a new concept in air warfare through the use of guided missiles. Following the war, the influx of foreign technology, primarily German, led to rapid advances in jet propulsion and speed, and a host of new problem areas associated with high-speed flight designs were revealed. The resolution of these problems led to a rash of new design concepts and many of the lessons learned, in principle, are still effective today. In addition to the technical lessons learned related to aircraft development programs, it might also be noted that some lessons involving the political and philosophical nature of aircraft development programs are worth attention.

Aeropropulsion 1987. Session 6: High-Speed Propulsion Technology

NASA Technical Reports Server (NTRS)

1987-01-01

NASA is conducting aeronautical research over a broad range of Mach numbers. In addition to the advanced CTOL propulsion research described in a separate session, the Lewis Research Center has intensified its efforts towards propulsion technology for selected high-speed flight applications. In a companion program, the Langley Research Center has also accomplished excellent research in Supersonic Combustion Ramjet (SCRAM) propulsion. What is presented in this session is an unclassified review of some of the propulsion research results that are applicable for supersonic to hypersonic vehicles. Not only is a review provided for several key work areas, it also presents a viewpoint on future research directions by calling attention to cycles, components, and facilities involved in this rapidly expanding field of work.

New model of flap-gliding flight.

PubMed

Sachs, Gottfried

2015-07-21

A new modelling approach is presented for describing flap-gliding flight in birds and the associated mechanical energy cost of travelling. The new approach is based on the difference in the drag characteristics between flapping and non-flapping due to the drag increase caused by flapping. Thus, the possibility of a gliding flight phase, as it exists in flap-gliding flight, yields a performance advantage resulting from the decrease in the drag when compared with continuous flapping flight. Introducing an appropriate non-dimensionalization for the mathematical relations describing flap-gliding flight, results and findings of generally valid nature are derived. It is shown that there is an energy saving of flap-gliding flight in the entire speed range compared to continuous flapping flight. The energy saving reaches the highest level in the lower speed region. The travelling speed of flap-gliding flight is composed of the weighted average of the differing speeds in the flapping and gliding phases. Furthermore, the maximum range performance achievable with flap-gliding flight and the associated optimal travelling speed are determined. Copyright © 2015 Elsevier Ltd. All rights reserved.

High speed civil transport aerodynamic optimization

NASA Technical Reports Server (NTRS)

Ryan, James S.

1994-01-01

This is a report of work in support of the Computational Aerosciences (CAS) element of the Federal HPCC program. Specifically, CFD and aerodynamic optimization are being performed on parallel computers. The long-range goal of this work is to facilitate teraflops-rate multidisciplinary optimization of aerospace vehicles. This year's work is targeted for application to the High Speed Civil Transport (HSCT), one of four CAS grand challenges identified in the HPCC FY 1995 Blue Book. This vehicle is to be a passenger aircraft, with the promise of cutting overseas flight time by more than half. To meet fuel economy, operational costs, environmental impact, noise production, and range requirements, improved design tools are required, and these tools must eventually integrate optimization, external aerodynamics, propulsion, structures, heat transfer, controls, and perhaps other disciplines. The fundamental goal of this project is to contribute to improved design tools for U.S. industry, and thus to the nation's economic competitiveness.

Effect of Tail Dihedral on Lateral Control Effectiveness at High Subsonic Speeds of Differentially Deflected Horizontal-Tail Surfaces on a Configuration having a Thin Highly Tapered Wing

NASA Technical Reports Server (NTRS)

Fournier, Paul G.

1959-01-01

Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel to determine the effect of tail dihedral on lateral control effectiveness of a complete-model configuration having differentially deflected horizontal-tail surfaces. Limited tests were made to determine the lateral characteristics as well as the longitudinal characteristics in sideslip. The wing had an aspect ratio of 3, a taper ratio of 0.14, 28.80 deg sweep of the quarter-chord line with zero sweep at the 80-percent-chord line, and NACA 65A004 airfoil sections. The test Mach number range extended from 0.60 to 0.92. There are only small variations in the roll effectiveness parameter C(sub iota delta) with negative tail dihedral angle. The tail size used on the test model, however, is perhaps inadequate for providing the roll rates specified by current military requirements at subsonic speeds. The lateral aerodynamic characteristics were essentially constant throughout the range of sideslip angle from 12 deg to -12 deg. A general increase in yawing moment was noted with increased negative dihedral throughout the Mach number range.

Supersonic Research Display for Tour

NASA Image and Video Library

1946-03-21

On March 22, 1946, 250 members of the Institute of Aeronautical Science toured the NACA’s Aircraft Engine Research Laboratory. NACA Chairman Jerome Hunsaker and Secretary John Victory were on hand to brief the attendees in the Administration Building before the visited the lab’s test facilities. At each of the twelve stops, researchers provided brief presentations on their work. Topics included axial flow combustors, materials for turbine blades, engine cooling, icing prevention, and supersonic flight. The laboratory reorganized itself in October 1945 as World War II came to an end to address newly emerging technologies such as the jet engine, rockets, and high-speed flight. While design work began on what would eventually become the 8- by 6-Foot Supersonic Wind Tunnel, NACA Lewis quickly built several small supersonic tunnels. These small facilities utilized the Altitude Wind Tunnel’s massive air handling equipment to generate high-speed airflow. The display seen in this photograph was set up in the building that housed the first of these wind tunnels. Eventually the building would contain three small supersonic tunnels, referred to as the “stack tunnels” because of the vertical alignment. The two other tunnels were added to this structure in 1949 and 1951. The small tunnels were used until the early 1960s to study the aerodynamic characteristics of supersonic inlets and exits.

Status of NASA High-Speed Research Program

NASA Technical Reports Server (NTRS)

Whitehead, Allen H., Jr.

1998-01-01

This paper provides an overview of the NASA High-Speed Research (HSR) Program dedicated to establishing the technology foundation to support the US transport industry's decision for an environmentally acceptable, economically viable 300 passenger, 5000 n.mi., Mach 2.4 aircraft. The HSR program, begun in 1990, is supported by a team of US aerospace companies. The international economic stakes are high. The projected market for more than 500 High-Speed Civil Transport (HSCT) airplanes introduced between the years 2000 and 2015 translates to more than $200 billion in aircraft sales, and the potential of 140,000 new jobs. The paper addresses the history of supersonic commercial air transportation beginning with the Concorde and TU-144 developments in the early 1960 time period. The technology goals for the HSR program are derived from market study results, projections on environmental requirements, and technical goals for each discipline area referenced to the design and operational features of the Concorde. Progress since the inception of the program is reviewed and a summary of some of the lessons learned will be highlighted. An outline is presented of the remaining technological challenges. Emphasis in this paper will be on the traditional aeronautical technologies that lead to higher performance to ensure economic viability. Specific discussion will center around aerodynamic performance, flight deck research, materials and structures development and propulsion systems. The environmental barriers to the HSCT and that part of the HSR program that addresses those technologies are reviewed and assessed in a companion paper.

High-speed real-time animated displays on the ADAGE (trademark) RDS 3000 raster graphics system

NASA Technical Reports Server (NTRS)

Kahlbaum, William M., Jr.; Ownbey, Katrina L.

1989-01-01

Techniques which may be used to increase the animation update rate of real-time computer raster graphic displays are discussed. They were developed on the ADAGE RDS 3000 graphic system in support of the Advanced Concepts Simulator at the NASA Langley Research Center. These techniques involve the use of a special purpose parallel processor, for high-speed character generation. The description of the parallel processor includes the Barrel Shifter which is part of the hardware and is the key to the high-speed character rendition. The final result of this total effort was a fourfold increase in the update rate of an existing primary flight display from 4 to 16 frames per second.

Quiet engine program flight engine design study

NASA Technical Reports Server (NTRS)

Klapproth, J. F.; Neitzel, R. E.; Seeley, C. T.

1974-01-01

The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included.

Hydrodynamic and Aerodynamic Tests of Models of Floats for Single-float Seaplanes NACA Models 41-D, 41-E, 61-A, 73, and 73-A

NASA Technical Reports Server (NTRS)

Parkinson, J B; HOUSE R O

1938-01-01

Tests were made in the NACA tank and in the NACA 7 by 10 foot wind tunnel on two models of transverse step floats and three models of pointed step floats considered to be suitable for use with single float seaplanes. The object of the program was the reduction of water resistance and spray of single float seaplanes without reducing the angle of dead rise believed to be necessary for the satisfactory absorption of the shock loads. The results indicated that all the models have less resistance and spray than the model of the Mark V float and that the pointed step floats are somewhat superior to the transverse step floats in these respects. Models 41-D, 61-A, and 73 were tested by the general method over a wide range of loads and speeds. The results are presented in the form of curves and charts for use in design calculations.

Application of high speed machining technology in aviation

NASA Astrophysics Data System (ADS)

Bałon, Paweł; Szostak, Janusz; Kiełbasa, Bartłomiej; Rejman, Edward; Smusz, Robert

2018-05-01

Aircraft structures are exposed to many loads during their working lifespan. Every particular action made during a flight is composed of a series of air movements which generate various aircraft loads. The most rigorous requirement which modern aircraft structures must fulfill is to maintain their high durability and reliability. This requirement involves taking many restrictions into account during the aircraft design process. The most important factor is the structure's overall mass, which has a crucial impact on both utility properties and cost-effectiveness. This makes aircraft one of the most complex results of modern technology. Additionally, there is currently an increasing utilization of high strength aluminum alloys, which requires the implementation of new manufacturing processes. High Speed Machining technology (HSM) is currently one of the most important machining technologies used in the aviation industry, especially in the machining of aluminium alloys. The primary difference between HSM and other milling techniques is the ability to select cutting parameters - depth of the cut layer, feed rate, and cutting speed in order to simultaneously ensure high quality, precision of the machined surface, and high machining efficiency, all of which shorten the manufacturing process of the integral components. In this paper, the authors explain the implementation of the HSM method in integral aircraft constructions. It presents the method of the airframe manufacturing method, and the final results. The HSM method is compared to the previous method where all subcomponents were manufactured by bending and forming processes, and then, they were joined by riveting.

JF-102A on ramp

NASA Technical Reports Server (NTRS)

1956-01-01

Convair JF-102A (54-1374) on the ramp at NACA High-Speed Flight Station , Edwards, California in 1956. The most prominent new feature distinguishing the JF-102A from the YF-102 was a longer fuselage with a pinched or 'coke-bottle' waist. Note wing-fences on both wings. The JF-102A Characteristics are: Wing Span, ft. 38.1 Fuselage length, ft. 63.4 Vertical Tail height, ft. 21.2 Power Plant: Pratt & Whitney J57-P-23 turbojet

Surface tension dominates insect flight on fluid interfaces

PubMed Central

Mukundarajan, Haripriya; Bardon, Thibaut C.; Kim, Dong Hyun; Prakash, Manu

2016-01-01

ABSTRACT Flight on the 2D air–water interface, with body weight supported by surface tension, is a unique locomotion strategy well adapted for the environmental niche on the surface of water. Although previously described in aquatic insects like stoneflies, the biomechanics of interfacial flight has never been analysed. Here, we report interfacial flight as an adapted behaviour in waterlily beetles (Galerucella nymphaeae) which are also dexterous airborne fliers. We present the first quantitative biomechanical model of interfacial flight in insects, uncovering an intricate interplay of capillary, aerodynamic and neuromuscular forces. We show that waterlily beetles use their tarsal claws to attach themselves to the interface, via a fluid contact line pinned at the claw. We investigate the kinematics of interfacial flight trajectories using high-speed imaging and construct a mathematical model describing the flight dynamics. Our results show that non-linear surface tension forces make interfacial flight energetically expensive compared with airborne flight at the relatively high speeds characteristic of waterlily beetles, and cause chaotic dynamics to arise naturally in these regimes. We identify the crucial roles of capillary–gravity wave drag and oscillatory surface tension forces which dominate interfacial flight, showing that the air–water interface presents a radically modified force landscape for flapping wing flight compared with air. PMID:26936640

Verification and Quantification of Single Event Effects on High Speed SRAM in Terrestrial Environments

NASA Technical Reports Server (NTRS)

Huff, H.; You, Z.; Williams, T.; Nichols, T.; Attia, J.; Fogarty, T. N.; Kirby, K.; Wilkins, R.; Lawton, R.

1998-01-01

As integrated circuits become more sensitive to charged particles and neutrons, anomalous performance due to single event effects (SEE) is a concern and requires experimental verification and quantification. The Center for Applied Radiation Research (CARR) at Prairie View A&M University has developed experiments as a participant in the NASA ER-2 Flight Program, the APEX balloon flight program and the Student Launch Program. Other high altitude and ground level experiments of interest to DoD and commercial applications are being developed. The experiment characterizes the SEE behavior of high speed and high density SRAM's. The system includes a PC-104 computer unit, an optical drive for storage, a test board with the components under test, and a latchup detection and reset unit. The test program will continuously monitor the stored checkerboard data pattern in the SW and record errors. Since both the computer and the optical drive contain integrated circuits, they are also vulnerable to radiation effects. A latchup detection unit with discrete components will monitor the test program and reset the system when necessary. The first results will be obtained from the NASA ER-2 flights, which are now planned to take place in early 1998 from Dryden Research Center in California. The series of flights, at altitudes up to 70,000 feet, and a variety of flight profiles should yield a distribution of conditions for correlating SEES. SEE measurements will be performed from the time of aircraft power-up on the ground throughout the flight regime until systems power-off after landing.

High-Speed, high-power, switching transistor

NASA Technical Reports Server (NTRS)

Carnahan, D.; Ohu, C. K.; Hower, P. L.

1979-01-01

Silicon transistor rate for 200 angstroms at 400 to 600 volts combines switching speed of transistors with ruggedness, power capacity of thyristor. Transistor introduces unique combination of increased power-handling capability, unusally low saturation and switching losses, and submicrosecond switching speeds. Potential applications include high power switching regulators, linear amplifiers, chopper controls for high frequency electrical vehicle drives, VLF transmitters, RF induction heaters, kitchen cooking ranges, and electronic scalpels for medical surgery.

A unified flight control methodology for a compound rotorcraft in fundamental and aerobatic maneuvering flight

NASA Astrophysics Data System (ADS)

Thorsen, Adam

regime. An energy management system was developed in order to manage performance limits (namely power required) to promote carefree maneuvering and alleviate pilot workload. This system features limits on pilot commands and has additional logic for preserving control margins and limiting maximum speed in a dive. Nonlinear dynamic inversion (NLDI) is the framework of the unified controller, which incorporates primary and redundant controls. The inner loop of the NLDI controller regulates bank angle, pitch attitude, and yaw rate, while the outer loop command structure is varied (three modes). One version uses an outer loop that commands velocities in the longitudinal and vertical axes (velocity mode), another commands longitudinal acceleration and vertical speed (acceleration mode), and the third commands longitudinal acceleration and transitions from velocity to acceleration command in the vertical axis (aerobatic mode). The flight envelope is discretized into low, cruise, and high speed flight regimes. The unified outer loop primary control effectors for the longitudinal and vertical axes (collective pitch, pitch attitude, and propeller pitch) vary depending on flight regime. A weighted pseudoinverse is used to phase either the collective or propeller pitch in/out of a redundant control role. The controllers were evaluated in Penn State's Rotorcraft Flight Simulator retaining the cyclic stick for vertical and lateral axis control along with pedal inceptors for yaw axis control. A throttle inceptor was used in place of the pilot's traditional left hand inceptor for longitudinal axis control. Ultimately, a simple rigid body model of the aircraft was sufficient enough to design a controller with favorable performance and stability characteristics. This unified flight control system promoted a low enough pilot workload so that an untrained pilot (the author) was able to pilot maneuvers of varying complexity with ease. The framework of this unified system is generalized

High-speed photogrammetry system for measuring the kinematics of insect wings

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

Wallace, Iain D.; Lawson, Nicholas J.; Harvey, Andrew R.

2006-06-10

We describe and characterize an experimental system to perform shape measurements on deformable objects using high-speed close-range photogrammetry. The eventual application is to extract the kinematics of several marked points on an insect wing during tethered and hovering flight. We investigate the performance of the system with a small number of views and determine an empirical relation between the mean pixel error of the optimization routine and the position error. Velocity and acceleration are calculated by numerical differencing, and their relation to the position errors is verified. For a field of view of {approx}40mmx40 mm, a rms accuracy of 30more » {mu}m in position, 150 mm/s in velocity, and 750 m/s2 in acceleration at 5000 frames/s is achieved. This accuracy is sufficient to measure the kinematics of hoverfly flight.« less

Unified aeroacoustics analysis for high speed turboprop aerodynamics and noise. Volume 5: Propagation of propeller tone noise through a fuselage boundary layer

NASA Technical Reports Server (NTRS)

Magliozzi, B.; Hanson, D. B.

1991-01-01

An analysis of tone noise propagation through a boundary layer and fuselage scattering effects was derived. This analysis is a three dimensional and the complete wave field is solved by matching analytical expressions for the incident and scattered waves in the outer flow to a numerical solution in the boundary layer flow. The outer wave field is constructed analytically from an incident wave appropriate to the source and a scattered wave in the standard Hankel function form. For the incident wave, an existing function - domain propeller noise radiation theory is used. In the boundary layer region, the wave equation is solved by numerical methods. The theoretical analysis is embodied in a computer program which allows the calculation of correction factors for the fuselage scattering and boundary layer refraction effects. The effects are dependent on boundary layer profile, flight speed, and frequency. Corrections can be derived for any point on the fuselage, including those on the opposite side from the source. The theory was verified using limited cases and by comparing calculations with available measurements from JetStar tests of model prop-fans. For the JetStar model scale, the boundary layer refraction effects produce moderate fuselage pressure reinforcements aft of and near the plane of rotation and significant attenuation forward of the plane of rotation at high flight speeds. At lower flight speeds, the calculated boundary layer effects result in moderate amplification over the fuselage area of interest. Apparent amplification forward of the plane of rotation is a result of effective changes in the source directivity due to boundary layer refraction effects. Full scale effects are calculated to be moderate, providing fuselage pressure amplification of about 5 dB at the peak noise location. Evaluation using available noise measurements was made under high-speed, high-altitude flight conditions. Comparisons of calculations made of free field noise, using a

Low-speed cascade investigation of loaded leading-edge compressor blades