77 FR 15647 - Special Local Regulation for Marine Events; Temporary Change of Dates for Recurring Marine Events...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-16

...- hull and twin-hull inboard hydroplanes racing in heats counter- clockwise around an oval race course... marine event. The event consists of approximately 50 V-hull and twin-hull inboard hydroplanes racing in...

75 FR 57167 - Safety Zone; CLS Fall Championship Hydroplane Race, Lake Sammamish, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-20

... waters of Lake Sammamish, WA for the Composite Laminate Specialties (CLS) Fall Championship Hydroplane... Delegation No. 0170.1 0 2. Add Sec. 165.T13-162 to read as follows: Sec. 165.T13-162 Safety Zone; Composite...

75 FR 32661 - Special Local Regulation; Hydroplane Exhibition, Detroit River, Detroit, MI

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-09

...-AA08 Special Local Regulation; Hydroplane Exhibition, Detroit River, Detroit, MI AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard will enforce a temporary special local regulation on the Detroit River, Detroit, Michigan from June 18, 2010 to June 20, 2010. This special local...

33 CFR 100.1303 - Annual Kennewick, Washington, Columbia Unlimited Hydroplane Races.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Annual Kennewick, Washington, Columbia Unlimited Hydroplane Races. 100.1303 Section 100.1303 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.1303...

76 FR 42549 - Columbia Unlimited Hydroplane Races; Kennewick, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-19

... Hydroplane Races. This regulation which restricts navigation and anchorage on the Columbia River for six days... have questions on this notice, call or e-mail BM1 Silvestre Suga III, Coast Guard Marine Safety Unit... Guard will enforce the regulations found in 33 CFR 100.1303 restricting regular navigation and anchoring...

33 CFR 100.1301 - Seattle seafair unlimited hydroplane race.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Washington bounded by the Interstate 90 (Mercer Island /Lacey V. Murrow) Bridge, the western shore of Lake Washington, and the east/west line drawn tangent to Bailey Peninsula and along the shoreline of Mercer Island... hydroplane race course and then to the northerly tip of Ohlers Island in Andrews Bay. The western zone is...

33 CFR 100.1301 - Seattle seafair unlimited hydroplane race.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Washington bounded by the Interstate 90 (Mercer Island /Lacey V. Murrow) Bridge, the western shore of Lake Washington, and the east/west line drawn tangent to Bailey Peninsula and along the shoreline of Mercer Island... hydroplane race course and then to the northerly tip of Ohlers Island in Andrews Bay. The western zone is...

33 CFR 100.1301 - Seattle seafair unlimited hydroplane race.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Washington bounded by the Interstate 90 (Mercer Island /Lacey V. Murrow) Bridge, the western shore of Lake Washington, and the east/west line drawn tangent to Bailey Peninsula and along the shoreline of Mercer Island... hydroplane race course and then to the northerly tip of Ohlers Island in Andrews Bay. The western zone is...

33 CFR 100.1301 - Seattle seafair unlimited hydroplane race.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Washington bounded by the Interstate 90 (Mercer Island /Lacey V. Murrow) Bridge, the western shore of Lake Washington, and the east/west line drawn tangent to Bailey Peninsula and along the shoreline of Mercer Island... hydroplane race course and then to the northerly tip of Ohlers Island in Andrews Bay. The western zone is...

33 CFR 100.1301 - Seattle seafair unlimited hydroplane race.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Washington bounded by the Interstate 90 (Mercer Island /Lacey V. Murrow) Bridge, the western shore of Lake Washington, and the east/west line drawn tangent to Bailey Peninsula and along the shoreline of Mercer Island... hydroplane race course and then to the northerly tip of Ohlers Island in Andrews Bay. The western zone is...

77 FR 55138 - Special Local Regulation: Hydroplane Races in Lake Sammamish, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

... Local Regulation: Hydroplane Races in Lake Sammamish, WA AGENCY: Coast Guard, DHS. ACTION: Notice of... Races within the Captain of the Port Puget Sound Area of Responsibility for the 2012 Fall Championship... September 30, 2012. This action is necessary to restrict vessel movement in the vicinity of the race courses...

78 FR 49921 - Safety Zone; Thunder on the Niagara, Niagara River, North Tonawanda, NY

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-16

... 1625-AA00 Safety Zone; Thunder on the Niagara, Niagara River, North Tonawanda, NY AGENCY: Coast Guard... portion of the Niagara River during the Thunder on the Niagara hydroplane race. This temporary safety zone... to ensure the safety of spectators and vessels during the Thunder on the Niagara hydroplane race...

76 FR 55558 - Special Local Regulation for Marine Events; Temporary Change of Dates for Recurring Marine Events...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-08

... in the Fifth Coast Guard District, John H. Kerr Reservoir, Clarksville, VA AGENCY: Coast Guard, DHS..., the ``Clarksville Hydroplane Challenge,'' hydroplane races on the waters of the John H. Kerr Reservoir... Reservoir, this regulation is necessary to provide for the safety of life on navigable waters during the...

77 FR 30891 - Hydroplane Races Within the Captain of the Port Puget Sound Area of Responsibility

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-24

... Races Within the Captain of the Port Puget Sound Area of Responsibility AGENCY: Coast Guard, DHS. ACTION... for Hydroplane Races within the Captain of the Port Puget Sound Area of Responsibility for the Tastin... necessary to restrict vessel movement in the vicinity of the race courses thereby ensuring the safety of...

76 FR 23185 - Hydroplane Races Within the Captain of the Port Puget Sound Area of Responsibility

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-26

... Races Within the Captain of the Port Puget Sound Area of Responsibility AGENCY: Coast Guard, DHS. ACTION..., Hydroplane Races within the Captain of the Port Puget Sound Area of Responsibility for the Tastin' n' Racin... have questions on this notice, call or e-mail Ensign Anthony P. LaBoy, Sector Puget Sound Waterways...

The effect of chine tires on nose gear water-spray characteristics of a twin engine airplane

NASA Technical Reports Server (NTRS)

Yager, T. J.; Stubbs, S. M.; Mccarty, J. L.

1975-01-01

An experimental investigation was performed to evaluate the effectiveness of nose gear chine tires in eliminating or minimizing the engine spray ingestion problem encountered on several occasions by the Merlin 4, a twin-engine propjet airplane. A study of the photographic and television coverage indicated that under similar test conditions the spray from the chine tires presented less of a potential engine spray ingestion problem than the conventional tires. Neither tire configuration appeared to pose any ingestion problem at aircraft speeds in excess of the hydroplaning speed for each tire, however, significant differences were noted in the spray patterns of the two sets of tires at sub-hydroplaning speeds. At sub-hydroplaning speeds, the conventional tires produced substantial spray above the wing which approached the general area of the engine air inlet at lower test speeds. The chine tires produced two distinct spray plumes at sub-hydroplaning speeds: one low-level plume which presented no apparent threat of ingestion, and one which at most test speeds was observed to be below the wing leading edge and thus displaced from the intakes on the engine nacelle.

Investigation of the Effect of Dimple Bionic Nonsmooth Surface on Tire Antihydroplaning.

PubMed

Zhou, Haichao; Wang, Guolin; Ding, Yangmin; Yang, Jian; Zhai, Huihui

2015-01-01

Inspired by the idea that bionic nonsmooth surfaces (BNSS) reduce fluid adhesion and resistance, the effect of dimple bionic nonsmooth structure arranged in tire circumferential grooves surface on antihydroplaning performance was investigated by using Computational Fluid Dynamics (CFD). The physical model of the object (model of dimple bionic nonsmooth surface distribution, hydroplaning model) and SST k - ω turbulence model are established for numerical analysis of tire hydroplaning. By virtue of the orthogonal table L16(4(5)), the parameters of dimple bionic nonsmooth structure design compared to the smooth structure were analyzed, and the priority level of the experimental factors as well as the best combination within the scope of the experiment was obtained. The simulation results show that dimple bionic nonsmooth structure can reduce water flow resistance by disturbing the eddy movement in boundary layers. Then, optimal type of dimple bionic nonsmooth structure is arranged on the bottom of tire circumferential grooves for hydroplaning performance analysis. The results show that the dimple bionic nonsmooth structure effectively decreases the tread hydrodynamic pressure when driving on water film and increases the tire hydroplaning velocity, thus improving tire antihydroplaning performance.

Investigation of the Effect of Dimple Bionic Nonsmooth Surface on Tire Antihydroplaning

PubMed Central

Zhou, Haichao; Wang, Guolin; Ding, Yangmin; Yang, Jian; Zhai, Huihui

2015-01-01

Inspired by the idea that bionic nonsmooth surfaces (BNSS) reduce fluid adhesion and resistance, the effect of dimple bionic nonsmooth structure arranged in tire circumferential grooves surface on antihydroplaning performance was investigated by using Computational Fluid Dynamics (CFD). The physical model of the object (model of dimple bionic nonsmooth surface distribution, hydroplaning model) and SST k − ω turbulence model are established for numerical analysis of tire hydroplaning. By virtue of the orthogonal table L16(45), the parameters of dimple bionic nonsmooth structure design compared to the smooth structure were analyzed, and the priority level of the experimental factors as well as the best combination within the scope of the experiment was obtained. The simulation results show that dimple bionic nonsmooth structure can reduce water flow resistance by disturbing the eddy movement in boundary layers. Then, optimal type of dimple bionic nonsmooth structure is arranged on the bottom of tire circumferential grooves for hydroplaning performance analysis. The results show that the dimple bionic nonsmooth structure effectively decreases the tread hydrodynamic pressure when driving on water film and increases the tire hydroplaning velocity, thus improving tire antihydroplaning performance. PMID:27018311

Evaluation of driver behavior to hydroplaning in the state of Florida using driving simulation.

DOT National Transportation Integrated Search

2012-08-01

This project used a driving simulator to investigate patterns of drivers' behavior during various rainfall events using different roadway geometries. The authors conducted a literature review of previous transportation studies using driving simulator...

76 FR 3057 - Special Local Regulation; Hydroplane Races Within the Captain of the Port Puget Sound Area of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-19

...: November 24, 2010. G.T. Blore, Rear Admiral, U.S. Coast Guard, Commander, Thirteenth Coast Guard District.... Voluntary consensus standards are technical standards (e.g., specifications of materials, performance...

Installation report on porous friction course hot plant mix.

DOT National Transportation Integrated Search

1972-01-01

An investigation was initiated in the spring of 1972 to develop surface mixes with high skid resistance for use at special locations. The porous friction course will hopefully provide high skid coefficients where water drainage and hydroplaning may b...

77 FR 25070 - Special Local Regulation for Marine Events; Temporary Change of Dates for Recurring Marine Events...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-27

... Atlantic Ocean near Ocean City, Maryland. The event consists of approximately 50 V- hull and twin-hull... consists of approximately 50 V-hull and twin-hull inboard hydroplanes racing in heats counter-clockwise...

Evaluation of trench and slotted drain maintenance and cleaning : Phase 1 : final report.

DOT National Transportation Integrated Search

2017-03-01

Trench and slotted drains are increasingly being used by ODOT to remove storm water from the roadways. These drains have to be properly cleaned and maintained to prevent vehicles from hydroplaning, eliminate flooding and avoid premature roadway failu...

Research showcase, summer 2014 : the value of roadside vegetation, hydroplane prediction tool, gearing up for automated vehicles.

DOT National Transportation Integrated Search

2014-01-01

This issue of Research Showcase highlights the value of roadside vegetation, from stabilizing soil, : which protects infrastructure and provides safe clear zones for errant vehicles, to providing habitat : for wildlife and crop pollinators. Recent FD...

76 FR 5510 - Safety Enhancements Part 139, Certification of Airports

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-01

... prevent accidents and incidents in that area. A certificate holder would be required to conduct pavement... Pavement Surface Evaluation Braking performance is critical for all aircraft especially on wet runway surfaces. Under certain conditions, hydroplaning or unacceptable loss of traction (tire/pavement contact...

Verification of rut depth collected with the INO laser rut measurement system (LRMS).

DOT National Transportation Integrated Search

2011-10-28

Pavement rutting can be an indicator that a section of roadway is in need of repair or replacement. It can also become : a hazard to drivers, causing loss of control or hydroplaning when water accumulates. To better monitor pavement : conditions thro...

78 FR 10685 - Reports, Forms, and Recordkeeping Requirements: Agency Information Collection Activity Under OMB...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-14

... Traffic Safety Administration Title: Tire Pressure Monitoring Systems Special Studies. OMB Number: 2174...: Improperly inflated tires pose a safety risk, increasing the chance of skidding, hydroplaning, longer stopping distances, and crashes due to flat tires and blowouts. In an effort to decrease the number of...

76 FR 37000 - Seattle Seafair Unlimited Hydroplane Race

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-24

... area; the waters of Lake Washington bounded by the Interstate 90 (Mercer Island/Lacey V. Murrow) Bridge... along the shoreline of Mercer Island. The regulated area has been divided into two zones. The zones are... race course and then to the northerly tip of Ohlers Island in Andrews Bay. The western zone is...

77 FR 39632 - Seattle Seafair Unlimited Hydroplane Race

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-05

... of Lake Washington bounded by the Interstate 90 (Mercer Island/Lacey V. Murrow) Bridge, the western... shoreline of Mercer Island. The regulated area has been divided into two zones. The zones are separated by a... course and then to the northerly tip of Ohlers Island in Andrews Bay. The western zone is designated Zone...

76 FR 17339 - Special Local Regulation; Hydroplane Races Within the Captain of the Port Puget Sound Area of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-29

... impact on a substantial number of small entities. The term ``small entities'' comprises small businesses.... Assistance for Small Entities Under section 213(a) of the Small Business Regulatory Enforcement Fairness Act.... Small businesses may send comments on the actions of Federal employees who enforce, or otherwise...

Tire/runway friction interface

NASA Technical Reports Server (NTRS)

Yager, Thomas J.

1990-01-01

An overview is given of NASA Langley's tire/runway pavement interface studies. The National Tire Modeling Program, evaluation of new tire and landing gear designs, tire wear and friction tests, and tire hydroplaning studies are examined. The Aircraft Landing Dynamics Facility is described along with some ground friction measuring vehicles. The major goals and scope of several joint FAA/NASA programs are identified together with current status and plans.

Status of runway slipperiness research

NASA Technical Reports Server (NTRS)

Horne, W. B.

1976-01-01

Runway slipperiness research performed in the United States and Europe since 1968 is reviewed. Topics discussed include: (1) runway flooding during rainstorms; (2) hydroplaning; (3) identification of slippery runways including the results from ground vehicle friction measurements and attempts to correlate these measurements with aircraft stopping performance; (4) progress and problems associated with the development of antihydroplaning runway surface treatments such as pavement grooving and porous friction course (PFC); and (5) runway rubber deposits and their removal.

Fore-and-aft stiffness and damping characteristics of 30 x 11.5-14.5, Type VIII, bias-ply and radial-belted aircraft tires

NASA Technical Reports Server (NTRS)

Lopez, Mercedes C.; Davis, Pamela A.; Yeaton, Robert B.; Vogler, William A.

1988-01-01

Measurements of footprint geometrical properties and fore and aft stiffness and damping characteristics were obtained on 30 x 11.5-14.5 bias-ply and radial-belted aircraft tires. Significant differences in stiffness and damping characteristics were found between the two design types. The results show that footprint aspect ratio effects may interfere with the improved hydroplaning potential associated with the radial-belted tire operating at higher inflation pressures.

Factors influencing aircraft ground handling performance

NASA Technical Reports Server (NTRS)

Yager, T. J.

1983-01-01

Problems associated with aircraft ground handling operations on wet runways are discussed and major factors which influence tire/runway braking and cornering traction capability are identified including runway characteristics, tire hydroplaning, brake system anomalies, and pilot inputs. Research results from tests with instrumented ground vehicles and aircraft, and aircraft wet runway accident investigation are summarized to indicate the effects of different aircraft, tire, and runway parameters. Several promising means are described for improving tire/runway water drainage capability, brake system efficiency, and pilot training to help optimize aircraft traction performance on wet runways.

Current Research in Aircraft Tire Design and Performance

NASA Technical Reports Server (NTRS)

Tanner, J. A.; Mccarthy, J. L.; Clark, S. K.

1981-01-01

A review of the tire research programs which address the various needs identified by landing gear designers and airplane users is presented. The experimental programs are designed to increase tire tread lifetimes, relate static and dynamic tire properties, establish the tire hydroplaning spin up speed, study gear response to tire failures, and define tire temperature profiles during taxi, braking, and cornering operations. The analytical programs are aimed at providing insights into the mechanisms of heat generation in rolling tires and developing the tools necessary to streamline the tire design process and to aid in the analysis of landing gear problems.

Review of factors affecting aircraft wet runway performance

NASA Technical Reports Server (NTRS)

Yager, T. J.

1983-01-01

Problems associated with aircraft operations on wet runways are discussed and major factors which influence tire/runway braking and cornering traction capability are identified including runway characteristics, tire hydroplaning, brake system anomalies, and pilot inputs. Research results from investigations conducted at the Langley Aircraft Landing Loads and Traction Facility and from tests with instrumented ground vehicles and aircraft are summarized to indicate the effects of different aircraft, tire, and runway parameters. Several promising means are described for improving tire/runway water drainage capability, brake system efficiency, and pilot training to help optimize aircraft traction performance on wet runways.

Aquatic burst locomotion by hydroplaning and paddling in common eiders (Somateria mollissima).

PubMed

Gough, William T; Farina, Stacy C; Fish, Frank E

2015-06-01

Common eiders (Somateria mollissima) are heavy sea-ducks that spend a large portion of their time swimming at the water surface. Surface swimming generates a bow and hull wave that can constructively interfere and produce wave drag. The speed at which the wavelengths of these waves equal the waterline length of the swimming animal is the hull speed. To increase surface swimming speed beyond the hull speed, an animal must overtake the bow wave. This study found two distinct behaviors that eider ducks used to exceed the hull speed: (1) 'steaming', which involved rapid oaring with the wings to propel the duck along the surface of the water, and (2) 'paddle-assisted flying', during which the ducks lifted their bodies out of the water and used their feet to paddle against the surface while flapping their wings in the air. An average hull speed (0.732±0.046 m s(-1)) was calculated for S. mollissima by measuring maximum waterline length from museum specimens. On average, steaming ducks swam 5.5 times faster and paddle-assisted flying ducks moved 6.8 times faster than the hull speed. During steaming, ducks exceeded the hull speed by increasing their body angle and generating dynamic lift to overcome wave drag and hydroplane along the water surface. During paddle-assisted flying, ducks kept their bodies out of the water, thereby avoiding the limitations of wave drag altogether. Both behaviors provided alternatives to flight for these ducks by allowing them to exceed the hull speed while staying at or near the water surface. © 2015. Published by The Company of Biologists Ltd.

Surface properties-vehicle interaction

NASA Astrophysics Data System (ADS)

Huft, D. L.; Her, I.; Agrawal, S. K.; Zimmer, R. A.; Bester, C. J.

Several topics related to the surface properties of aircraft runways are discussed. The South Dakota profilometer; development of a data acquisition method for noncontact pavement macrotexture measurement; the traction of an aircraft tire on grooved and porous asphaltic concrete; holes in the pavements; the effect of pavement type and condition on the fuel consumption of vehicles; the traction loss of a suspended tire on a sinusoidal road; the effect of vehicle and driver characteristics on the psychological evaluation of road roughness; the correlation of subjective panel ratings of pavement ride quality with profilometer-derived measures of pavement roughness; a microprocessor-based noncontact distance measuring control system, and, the representation of pavement surface topography in predicting runoff depths and hydroplaning potential are discussed.

Oleoplaning droplets on lubricated surfaces

NASA Astrophysics Data System (ADS)

Daniel, Dan; Timonen, Jaakko V. I.; Li, Ruoping; Velling, Seneca J.; Aizenberg, Joanna

2017-10-01

Recently, there has been much interest in using lubricated surfaces to achieve extreme liquid repellency: a foreign droplet immiscible with the underlying lubricant layer was shown to slide off at a small tilt angle <5°. This behaviour was hypothesized to arise from a thin lubricant overlayer film sandwiched between the droplet and solid substrate, but this has not been observed experimentally. Here, using thin-film interference, we are able to visualize the intercalated film under both static and dynamic conditions. We further demonstrate that for a moving droplet, the film thickness follows the Landau-Levich-Derjaguin law. The droplet is therefore oleoplaning--akin to tyres hydroplaning on a wet road--with minimal dissipative force and no contact line pinning. The techniques and insights presented in this study will inform future work on the fundamentals of wetting for lubricated surfaces and enable their rational design.

The Versatile Elastohydrodynamics of a Free Particle near a Thin Soft Wall

NASA Astrophysics Data System (ADS)

Salez, Thomas; Saintyves, Baudouin; Mahadevan, L.

2015-03-01

We address the free motion of a buoyant particle inside a viscous fluid, in the vicinity of a thin compressible elastic wall. After discussing the main scalings, we obtain analytically the dominant drag forces within the soft lubrication approximation. By including those into the equations of motion of the particle, we establish a general governing system of three coupled nonlinear and singular differential equations, that describe the three essential motions: sedimentation, hydroplaning, and hydrospinning, through four dimensionless control parameters. Numerical integration allows us to predict a wide zoology of exotic solutions - despite the low-Reynolds feature of the flow - including: spontaneous oscillation, Magnus-like effect, enhanced sedimentation, and boomerang-like effect. We compare these predictions to experiments. The presented elementary approach could be of interest in the description of a broad variety of elastohydrodynamical phenomena, including: landslides, ageing of cartilaginous joints, and motion of a cell in a microfluidic channel or in a blood vessel.

Cornering characteristics of a 40 by 14-16 type 7 aircraft tire and a comparison with characteristics of a C40 by 14-21 cantilever aircraft tire

NASA Technical Reports Server (NTRS)

Tanner, J. A.; Dreher, R. C.

1973-01-01

An investigation was conducted at the Langley aircraft landing loads and traction facility to determine the cornering characteristics of a 40 x 14-16 type VII aircraft tire. These characteristics, which include the cornering-force and drag-force friction coefficients and self-alining torque, were obtained for the tire operating on dry, damp and flooded runway surfaces over a range of yaw angles from 0 deg to 20 deg and at ground speeds from 5 to 100 knots, both with and without braking. The results of this investigation indicated that the cornering capability of the 40 x 14-16 type VII aircraft tire is degraded by high ground speeds, thin-film lubrication and tire hydroplaning effects on the wet surfaces, and brake torque. The cornering capability is greatly diminished when locked-wheel skids are encountered.

Screening and identification of a cutinase-producing Rhodotorula mucilaginosa and properties of the cutinase.

PubMed

Zhang, Xiao-Ning; Ran, Qin-Qin; Zhang, Xuejun

2015-01-01

Eucommia leaf contains large amounts of natural active products. In extracting the substances, the most important is the removal of the cuticle layer on the leaves and the cell wall in the leaves of Eucommia ulmoides. But the removal of the cuticle layer is a technical difficulty now. Cutinase (EC3.1.1.74) is a multifunctional enzyme with a common alpha/beta fold structure belonging to hydroplane that can make a substantial degradation of horny fatty acids. So this study isolated bacteria capable of producing cutinase from the lesion of Eucommia leaves and identified the bacteria. The identification using PCR-RFLP method confirmed that the strain belongs to Rhodotorula mucilaginosa. The fermentation conditions of the strain-producing cutinase were optimized in this study. The finding of cutinase-producing R. mucilaginosa is significant because the yeast is more secure than plant pathogens, being suitable for mass production.

Experimental investigation of the braking and cornering characteristics of 30 x 11.5-14.5, type 8, aircraft tires with different tread patterns

NASA Technical Reports Server (NTRS)

Dreher, R. C.; Tanner, J. A.

1974-01-01

An investigation was conducted at the aircraft landing loads and traction facility to study the braking and cornering characteristics, including the drag-force and cornering-force friction coefficients, of 30 by 11.5-14.5, type VIII aircraft tires with five different tread patterns. Test data were obtained on dry, damp, and flooded runway surfaces over a range of yaw angles from 0 deg to 12 deg at ground speeds from 5 knots to 100 knots. The results of this investigation indicate that a tread pattern consisting of transverse cuts across the entire width of the tread slightly improved the tire traction performance on wet surfaces. The braking and cornering capability of the tires was degraded by thin-film lubrication and tire hydroplaning effects on the wet runway surfaces. The braking capability of the tires decreased when the yaw angle was increased.

Use of biomimetic hexagonal surface texture in friction against lubricated skin.

PubMed

Tsipenyuk, Alexey; Varenberg, Michael

2014-05-06

Smooth contact pads that evolved in insects, amphibians and mammals to enhance the attachment abilities of the animals' feet are often dressed with surface micropatterns of different shapes that act in the presence of a fluid secretion. One of the most striking surface patterns observed in contact pads of these animals is based on a hexagonal texture, which is recognized as a friction-oriented feature capable of suppressing both stick-slip and hydroplaning while enabling friction tuning. Here, we compare this design of natural friction surfaces to textures developed for working in similar conditions in disposable safety razors. When slid against lubricated human skin, the hexagonal surface texture is capable of generating about twice the friction of its technical competitors, which is related to it being much more effective at channelling of the lubricant fluid out of the contact zone. The draining channel shape and contact area fraction are found to be the most important geometrical parameters governing the fluid drainage rate.

Some effects of grooved runway configurations on aircraft tire braking traction under flooded runway conditions

NASA Technical Reports Server (NTRS)

Byrdsong, T. A.

1973-01-01

An experimental investigation was conducted to study the effect of grooved runway configurations on aircraft tire braking traction on flooded runway surfaces. The investigation was performed, utilizing size 49 x 17, type VII, aircraft tires with an inflation pressure of 170 lb per square inch at ground speeds up to approximately 120 knots. The results of this investigation indicate that when the runway is flooded, grooved surfaces provide better braking traction than an ungrooved surface and, in general, the level of braking traction was found to improve as the tire bearing pressure was increased because of an increase in the groove area of either the surface or the tire tread. Rounding the groove edges tended to degrade the tire braking capability from that developed on the same groove configuration with sharp edges. Results also indicate that braking friction coefficients for the test tires and runway surfaces decreased as ground speed was increased because of the hydroplaning effects.

Experimental investigation of the cornering characteristics of 18 by 5.5, type 7, aircraft tires with different tread patterns

NASA Technical Reports Server (NTRS)

Dreher, R. C.; Tanner, J. A.

1974-01-01

The characteristics, which include the cornering-force and drag-force friction coefficients and self-alining torque, were obtained on dry, damp, and flooded runway surfaces over a range of yaw angles from 0 deg to 12 deg and at ground speeds from approximately 5 to 90 knots. The results indicate that a tread pattern with pinholes in the ribs reduces the tire cornering capability at high yaw angles on a damp surface but improves cornering on a dry surface. A tread pattern which has transverse grooves across the entire width of the tread improves the tire cornering performance slightly at high speeds on the flooded runway surface. The cornering capability of all the tires is degraded at high ground speeds by thin film lubrication and/or tire hydroplaning effects. Alterations to the conventional tread pattern provide only marginal improvements in the tire cornering capability which suggests that runway surface treatments may be a more effective way of improving aircraft ground performance during wet operations.

Runway drainage characteristics related to tire friction performance

NASA Technical Reports Server (NTRS)

Yager, Thomas J.

1991-01-01

The capability of a runway pavement to rapidly drain water buildup during periods of precipitation is crucial to minimize tire hydroplaning potential and maintain adequate aircraft ground operational safety. Test results from instrumented aircraft, ground friction measuring vehicles, and NASA Langley's Aircraft Landing Dynamics Facility (ALDF) track have been summarized to indicate the adverse effects of pavement wetness conditions on tire friction performance. Water drainage measurements under a range of rainfall rates have been evaluated for several different runway surface treatments including the transversely grooved and longitudinally grinded concrete surfaces at the Space Shuttle Landing Facility (SLF) runway at NASA Kennedy Space Center in Florida. The major parameters influencing drainage rates and extent of flooding/drying conditions are identified. Existing drainage test data are compared to a previously derived empirical relationship and the need for some modification is indicated. The scope of future NASA Langley research directed toward improving empirical relationships to properly define runway drainage capability and consequently, enhance aircraft ground operational safety, is given.

An evaluation of some unbraked tire cornering force characteristics

NASA Technical Reports Server (NTRS)

Leland, T. J. W.

1972-01-01

An investigation to determine the effects of pavement surface condition on the cornering forces developed by a group of 6.50x13 automobile tires of different tread design was conducted at the Langley aircraft landing loads and traction facility. The tests were made at fixed yaw angles of 3,4.5, and 6 deg at forward speeds up to 80 knots on two concrete surfaces of different texture under dry, damp, and flooded conditions. The results showed that the cornering forces were extremely sensitive to tread pattern and runway surface texture under all conditions and that under flooded conditions tire hydroplaning and complete loss of cornering force occurred at a forward velocity predicted from an existing formula based on tire inflation pressure. Futher, tests on the damp concrete with a smooth tire and a four-groove tire showed higher cornering forces at a yaw angle of 3 deg than at 4.5 deg; this indicated that maximum cornering forces are developed at extremely small steering angles under these conditions.

Drainage hydraulics of permeable friction courses

NASA Astrophysics Data System (ADS)

Charbeneau, Randall J.; Barrett, Michael E.

2008-04-01

This paper describes solutions to the hydraulic equations that govern flow in permeable friction courses (PFC). PFC is a layer of porous asphalt approximately 50 mm thick that is placed as an overlay on top of an existing conventional concrete or asphalt road surface to help control splash and hydroplaning, reduce noise, and enhance quality of storm water runoff. The primary objective of this manuscript is to present an analytical system of equations that can be used in design and analysis of PFC systems. The primary assumptions used in this analysis are that the flow can be modeled as one-dimensional, steady state Darcy-type flow and that slopes are sufficiently small so that the Dupuit-Forchheimer assumptions apply. Solutions are derived for cases where storm water drainage is confined to the PFC bed and for conditions where the PFC drainage capacity is exceeded and ponded sheet flow occurs across the pavement surface. The mathematical solutions provide the drainage characteristics (depth and residence time) as a function of rainfall intensity, PFC hydraulic conductivity, pavement slope, and maximum drainage path length.

Commentary: legal minimum tread depth for passenger car tires in the U.S.A.--a survey.

PubMed

Blythe, William; Seguin, Debra E

2006-06-01

Available tire traction is a significant highway safety issue, particularly on wet roads. Tire-roadway friction on dry, clean roads is essentially independent of tread depth, and depends primarily on roadway surface texture. However, tire-wet-roadway friction, both for longitudinal braking and lateral cornering forces, depends on several variables, most importantly on water depth, speed and tire tread depth, and the roadway surface texture. The car owner-operator has control over speed and tire condition, but not on water depth or road surface texture. Minimum tire tread depth is legislated throughout most of the United States and Europe. Speed reduction for wet road conditions is not.A survey of state requirements for legal minimum tread depth for passenger vehicle tires in the United States is presented. Most states require a minimum of 2/32 of an inch (approximately 1.6 mm) of tread, but two require less, some have no requirements, and some defer to the federal criterion for commercial vehicle safety inspections. The requirement of 2/32 of an inch is consistent with the height of the tread-wear bars built in to passenger car tires sold in the United States, but the rationale for that requirement, or other existing requirements, is not clear. Recent research indicates that a minimum tread depth of 2/32 of an inch does not prevent significant loss of friction at highway speeds, even for minimally wet roadways. The research suggests that tires with less than 4/32 of an inch tread depth may lose approximately 50 percent of available friction in those circumstances, even before hydroplaning occurs. It is concluded that the present requirements for minimum passenger car tire tread depth are not based upon rational safety considerations, and that an increase in the minimum tread depth requirements would have a beneficial effect on highway safety.

Experimental study of subaqueous, clay-rich, gravity flows

NASA Astrophysics Data System (ADS)

Marr, J.; Pratson, L.

2003-04-01

Recent laboratory experiments suggest a broad spectrum of flow and depositional behavior for compositionally varied subaqueous gravity flows. Dilute turbidity currents and cohesive debris flows are the end members of the spectrum. In this study we used geometrically scaled laboratory experiments to examine the flow dynamics and deposits associated with slurries of varying sediment composition. Slurries were composed of a mixture of tap water, kaolinite clay, 45 micron silt and 120 micron sand and were introduced into a 0.2m wide submerged channel. Slurry sediment concentrations ranged from 1-30% by volume. In all slurries, sediment was added in a ratio of 8:1:1 by volume of clay, silt, sand. A total volume of one cubic meter of slurry was used for each experiment and was introduced through a constant head tank allowing examination of sustained and steady gravity flow events lasting up to 5 minutes in duration. The dynamics of the flows (turbulence, hydroplaning, laminar shearing, etc.) were examined through the use of digital video cameras, dye injection tracking, high frequency sonar and visual observation. Vertical suspended sediment concentration and vertical grain size distributions were measured for each run from samples collected from siphon rakes. Deposit thicknesses and grain size distributions were measured from sediment samples taken from flow deposits. Rheological measurements and Atterberg limits of the slurries were made in an effort to link flow and depositional characteristics to bulk properties of the slurry mixture. The experiments show a clear linkage between the initial compositions of the slurries, their rheological properties, flow dynamics and deposits. Slurries with clay concentrations below 10% by volume appeared to be very turbulent. The silt and sand deposited during these events were transported along the bed as ripples. Flows between 10-20% sediment by volume appeared to be hybrid flows having both turbulent and non-turbulent elements. The surfaces of these deposits were flat and featureless. Slurries with sediment concentrations between 25-30% were clearly debris flows. They had distinguishable laminar flow and the deposit surfaces had both compression features and tension cracks.

Granular flow behavior at sharp changes in slope

NASA Astrophysics Data System (ADS)

Crosta, Giovanni; De Blasio, Fabio; Locatelli, Michele

2015-04-01

This study extends some recent experiments and analyses performed by the authors to examine the behavior of granular flows along path characterised by sharp changes in slope. In particular, various series of experiments along a bi-linear broken slope (an inclined initial sector followed by a horizontal one) have been completed using a uniform (Hostun, 0.32 mm) sand and a uniform fine gravel (2 mm grains). 60 new have been performed by releasing different volumes (1.5, 2.1 and 5.1 L) on surfaces characterized by different slope angles (35-60°), type of materials (wood and plexiglass), with or without an erodible layer (sand), or in presence of a shallow water pond (0.5 cm). These geometrical features are typical of many large rock and snow avalanches, rock falls and of chalk flows. The latter are usually typical of coastal cliffs where a shallow water environment is typical. The evolution of the flow has been monitored through a laser profilometer at 120 Hz sampling frequency and high speed camera, and in this way it has been possible to follow the evolution of the flow and deposition, and to analyse the change in deposition mode at varying the slope angle, the material and the basal friction. This is an extremely interesting development in the study of the evolution of the deposition and of the final morphology typical of such phenomena, and can support the testing of numerical models. Propagation and deposition occur forward or backward accordingly to the slope angle and the basal friction. Forward movement and deposition occur at high slope angles and with low basal friction. The opposite is true for the backward deposition. The internal "layering" within the deposit is also strongly controlled by the combination of such parameters. The time evolution of the flow allowed to determine the velocity of flow and the mode of deposition through the analysis of the change in thickness, position of the front and of the flow tail. Presence of water reduces the runout of the sand on the horizontal sector of the path, whereas the opposite seems true for the gravel. In these cases, as already shown by the authors (Crosta et al., submitted), a partial reflection of the flow occurs and the same holds true when a shallow water reservoir exists. Furthermore, a sort of hydroplaning phenomenon occurs which controls the initial part of the expansion along the subhorizontal sector of the path. Results of the experimental campaign have been compared against those from simple analytical models which assume the energy loss at the slope break and numerical simulations performed by a FEM-ALE (2D and fully 3D) modeling.

Incorporating the transverse profile of the wearing course into the control of the hot in-place recycling of asphalt concrete

NASA Astrophysics Data System (ADS)

Makowska, Michalina; Huuskonen-Snicker, Eeva; Alanaatu, Pauli; Aromaa, Kalle; Savarnya, Abhishek; Pellinen, Terhi; Das, Animesh

2018-05-01

The hot in-place recycling (HIR) of asphalt concrete (AC) is one of the least CO2 emissive reuse techniques. It allows for 100% reuse of material in-situ in the same application, at a reduced need for the material transport to and back from the construction site, as well as the reduced price in comparison with the fresh wearing course overlay. Finland uses the technique predominantly to fill wheel path ruts caused by the studded tire abrasion, to retain structural capacity and prevent hydroplaning. During the HIR process, the aged AC material is heated up in-situ, milled to the approximate depth of 40 mm, blended with fresh AC admixture and rejuvenator. However, the amount of the aged material and the amount of the aged bitumen that undergoes rejuvenation depends on the pavement transverse profile. The rut depth, width and shape determine the minimum volume of admixture necessary for refill during the process in order to retain the structural capacity, as well as the amount of the aged binder requiring rejuvenation. In favor of achieving homogenous rheological properties in the final product, the proportion between the aged binder and the fresh binder should be controlled, as it influences the required amount of rejuvenator. Therefore, the rut cross-sectional area and furthermore, the rut volume is one of the previously unrecognized or ignored major variables of the hot in-place recycling process in Finland that should be incorporated to the HIR process control. This article demonstrates the methodology of incorporating the transverse road profile measurements by 17 vehicle-mounted laser sensors into the calculation of required rejuvenator amounts. This can be done during the procurement preparation phase or during the paving work as a continuous in-situ process control. In the rheological optimization the apparent Newtonian viscosity concept and the rotational viscosity are utilized in the viscosity based blending equation, which then allows the use of oily rejuvenators. The method reduces the need for aged pavement sampling compared with the determination of the calibration curve between rejuvenator concentration and the rheological response. Additionally, the apparent Newtonian viscosity corrects the complex viscosity by the phase angle derived correction factor, opening a previously unexplored opportunity of targeting desired viscoelastic characteristics. The approach is less sensitive to the frequencies and temperatures at which the shear measurements are conducted. This makes proposed calculative method of the desired proportioning of the aged binder, the fresh binder and the rejuvenator a promising tool for the industry. The combined algorithm presented allows for: the discrimination of sites where HIR type maintenance of pavement in question would result in a substandard product; the choice of the most promising material combination of the admixture and rejuvenator, as well as for the adjustment of the admixture and rejuvenator amount in-place.

Experimental and theoretical investigation of the role of clay in subaqueous sediment flows and its effect on run-out distance

NASA Astrophysics Data System (ADS)

Hermidas, Navid; Luthi, Stefan; Eggenhuisen, Joris; Silva Jacinto, Ricardo; Toth, Ferenc; Pohl, Florian; de Leeuw, Jan

2016-04-01

Debris flows are driven by gravity, which in the tail region is overcome by the yield strength of the flow, forcing it to freeze. These flows are capable of achieving staggeringly large run-out distances on low gradients. The case in point, described in previous publications, is the flow which resulted in the deposit of Bed 5 of the Agadir megaslide on the north-west African margin. Debrites of this flow have been recorded several hundred kilometres away from the original landslide. Previous studies have attributed such long run-out distances to hydroplaning, low yield strength, and flow transformation. It is known that the net force acting on a volume of fluid in equilibrium is zero. In this work we show that clay-laden flows are capable of approaching equilibrium. The flows which can achieve the maximum run-out distance are cohesive enough to resist some of the surrounding disturbances, that can upset the equilibrium, and reach close to equilibrium conditions, yet are dilute enough to have low viscous stress, and relatively low yield strength and lose little sediment due to deposition. A flow that is not in equilibrium will always seek to approach equilibrium conditions by speeding up or slowing down, depositing sediment, eroding the substrate, contracting in the form of the tail approaching the head, stretching, entraining water and growing in height, or dewatering and collapsing. Here we present a theory that shows that two dimensional (2D) flows in equilibrium do not grow in height. 2D flume experiments were conducted on different mixtures of kaolinite, sand, silt, and water, on varying slopes and a transitionally rough bed (sand glued), and using various discharge rates, in order to map out different stages in the evolution of a density flow from a cohesive plug flow into a turbidity current. The following flow types were observed: high density turbidity currents, plug flows, and no flow. From the velocity profiles, certain runs demonstrated close to equilibrium behaviour. For these flows, very little flow height growth and velocity variation was observed over the length of the flume. In all cases the flow appeared to be laminar within the boundary layer with Kelvin-Helmholtz instabilities at the top which were suppressed to a large extent for higher sediment concentrations. A deposit consisting of thick muddy sand, with approximately uniform thickness, was observed for higher sediment concentrations, indicating relatively higher yield strength values, while a thinner more sandy deposit was observed for more dilute flows. It was concluded that high sediment concentrations on more moderate slopes result in slower moving plug flows which are capable of suppressing turbulence at the top, while lower sediment concentrations on steeper slopes result in faster moving, more turbulent currents. The flows which can achieve the largest run-out distance are located between these two extremes.

Sedimentological processes in a scarp-controlled rocky shoreline to upper continental slope environment, as revealed by unusual sedimentary features in the Neogene Coquimbo Formation, north-central Chile

NASA Astrophysics Data System (ADS)

Le Roux, J. P.; Gómez, Carolina; Fenner, Juliane; Middleton, Heather

2004-03-01

Exceptionally good outcrops of Miocene to Pliocene deposits in the vicinity of submarine Paleozoic basement scarps at Carrizalillo, north of La Serena, reveal a wealth of sedimentary features not commonly observed. The most proximal facies consist of rock fall and coarse-grained debris flow deposits directly abutting the basement wall from which they originated. Angular basement clasts are mixed with well-rounded cobbles, which probably formed as a basal gravel on a wave-cut platform at the beginning of marine flooding, subsequently accumulated at the scarp edge and were incorporated into the debris when the latter collapsed. The poor sorting, inverse grading, and protruding cobbles and boulders are classical debris flow features, with good clast imbrication indicating a laminar shearing action. A medial facies is represented by secondary channels running parallel to the major scarp about 1 km downslope of the first locality. In the largest channel, megaflutes at the base indicate the passage of highly turbulent, nondepositing flows eroding the soft, silty substrate. In the deepest, central part of the channel, a pebbly coquina shows horizontal and trough cross-stratification, with most of the bivalves oriented convex side up. Meter-scale rip-up clasts of the underlying siltstone are also present, indicating turbulent flow with a density sufficiently high to retard settling. The coquina is interpreted as a detachment deposit resulting from a hydroplaning debris flow along the central part of the channel, where the velocity and rate of pore pressure decay were highest. This deposit is overlain by fining upward, massive to horizontally stratified sandstone very similar in texture and composition to the matrix of the debris flow, suggesting its formation by surface transformation and elutriation of the latter. Along the channel margin, a basal centimeter-scale sandstone layer is virtually unaffected by the megaflute topography and clearly represents a subsequent event. It is interpreted as a basal shear carpet driven by the overlying debris flow. Within the shear carpet, a basal friction zone and an overlying collision zone containing a higher concentration of shell hash can be distinguished. The overlying debris flow deposit is represented by massive coquina with scattered, angular to rounded basement clasts. It contains disarticulated bivalves oriented with their concave side up, indicating large-scale upward fluid escape during deposition. A smaller secondary channel shows large rip-up rafts of the underlying substrate. Some rafts appear to have been plucked from the substrate by a process of sand injection from an overriding high-density sandy debris flow, which probably originated during a tsunami. Such clasts can climb upward into a laminar flow by down-current tilting and tumbling. The most distal facies occurs below a second scarp oriented more or less parallel to the present coastline, where finer-grained turbidites onlap and backlap onto the stoss and lee sides of an obstacle formed by eroded boulder conglomerates. The onlap deposits resemble inclined sandy macroforms recently described in submarine canyon settings. They are interbedded with diatom-containing, volcanic ash beds with cross-stratification dipping eastwards and containing deepwater microflora typical of continental upwelling zones.