Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Airport”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,531 records · Page 85
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Viscous effects on a vortex wake in ground effect

Wake vortex trajectories and strengths are altered radically by interactions with the ground plane. Prediction of vortex strength and location is especially important in the vicinity of airports. Simple potential flow methods have been found to yield reasonable estimates of vortex descent rates in an otherwise quiescent ambient background, but those techniques cannot be adjusted for more realistic ambient conditions and they fail to provide satisfactory estimates of ground-coupled behavior. The authors have been involved in a systematic study concerned with including viscous effects in a wake-vortex system which is near the ground plane. The study has employed numerical solutions to the Navier-Stokes equations, as well as perturbation techniques to study ground coupling with a descending vortex pair. Results of a two-dimensional, unsteady numerical-theoretical study are presented in this paper. A time-based perturbation procedure has been developed which permits the use of analytical solutions to an inner and outer flow domain for the initial flow field. Predictions have been compared with previously reported laminar experimental results. In addition, the influence of stratification and turbulence on vortex behavior near the ground plane has been studied.

Zheng, Z.↗
NASA NTRS1992

Airborne Lidar Measurements of Stratospheric Aerosols During the European Arctic Stratospheric Ozone Experiment (EASOE)

The European Arctic Statospheric Ozone Experiment was performed during the winter of 1991/1992 to study processes in the Arctic Stratosphere, which possibly might result in an ozone depletion similar to what has been found in the Antarctic. Besides a number of ground observations at several locations and numerous balloon borne in situ and remote sensing experiments, three aircrafts were operating from the airport of Kiruna, Sweden, two of them equipped with lidars. Various aspects of this investigation are presented.

Renger, Wolfgang↗
NASA NTRS1992

Dense fog on the highway: Visual range monitoring in cars?

This paper reports on the development of a new sensor. Laser range-finders are currently installed in cars and trucks to measure the distance to a proceeding car (LEICA). A modification of such a sensor to measure visibility was made. The problems that had to be solved were: (1) choice of wavelength with relation to the human eye for visibility measurements; (2) dependency of the wavelength on atmospheric turbidity; (3) laser eye-safety; and (4) influence of multiple scattering at visibilities smaller than 200 m. The wavelength used for lidar sensors in the near infrared presents no real problems because the object to be sensed is fog appearing white which means that scattering from fog is wavelength independent. There are however differences in backscatter-to-extinction ratio for different fog and weather situations. The two solutions to these problems are polarization and multiple scattering. As known from airport operations of a laser ceilometer, one can use this multiple scattering contribution to determine the visibility.

Hahn, W.↗
NASA NTRS1992

Building vibrations induced by noise from rotorcraft and propeller aircraft flyovers

Noise and building vibrations were measured for a series of helicopter and propeller-driven aircraft flyovers at WFF during May 1978. The building response data are compared with similar data acquired earlier at sites near Dulles and Kennedy Airports for operation of commercial jet transports, including the Concorde supersonic transport. Results show that noise-induced vibration levels in windows and walls are directly proportional to sound pressure level and that for a given noise level, the acceleration levels induced by a helicopter or a propeller-driven aircraft flyover cannot be distinguished from the acceleration levels induced by a commercial jet transport flyover. Noise-induced building acceleration levels were found to be lower than those levels which might be expected to cause structural damage and were also lower than some acceleration levels induced by such common domestic events as closing windows and doors.

Shepherd, Kevin P.↗
NASA NTRS1992

Impacts of technology on the capacity needs of the US national airspace system

A review of the U.S. air transportation system is undertaken, focusing on airspace and airport capacity. Causes of delay and congestion are investigated. Aircraft noise is identified as the fundamental hindrance to capacity improvement. Research areas for NASA are suggested to improve capacity through technology.

Ausrotas, Raymond A.↗
NASA NTRS1990

A DFW microburst model based on DL-191 data

Analysis of the August 2, 1985 crash of an L-1011 jumbo jet (DL-191), on approach to the Dallas-Ft. Worth International Airport (DFW) in a thunderstorm indicates that the severe windshear microburst which caused the crash was composed not only of a strong downflow and outflow but also included several large-scale vortex rings entrained in the flowfield. A detailed two-dimensional model of the DFW microburst, based on data from DL-191, is presented. The model uses wind vector and flight path data reconstructed by NASA-Ames Research Center from the L-1011's digital flight data records and ground-based radar measurements. The model was developed using a combination of interactive graphics and a least-square-error best fit between the modeled and measured wind vectors along the DL-191 flight path. The model confirms a microburst structure based on a von Karman vortex street rather than on a Kelvin-Helmholtz instability and indicates that the L-1011 flew near or directly through several strong vortices. In addition, the results also confirm that the reconstructed wind vector data contain a time lag in the horizontal winds. For the DL-191 this lag is approximately three seconds.

Grantham, Walter J.↗
NASA NTRS1990

Processing and analysis of radiometer measurements for airborne reconnaissance

This paper describes selected results of airborne, radiometric imaging measurements at 90 GHz and 140 GHz relevant for the application in reconnaissance. Using a temperature resolution below 0.5 K and an angular resolution of about 1-degree high-quality images show the capability of discriminating between many brightness temperature classes within our natural environment and man-made objects. Measurement examples are given for cloud and fog penetration at 90 GHz, for the detection of vehicles on roads, and for the detection and classification of airports and airplanes. The application of different contour enhancement methods (Marr-Hildreth and Canny) shows the possibility of extracting lines and shapes precisely in order to improve automatic target recognition. The registration of the passive images with corresponding X-band synthetic aperture images from the same area is carried out and the high degree of correlation is discussed.

Suess, Helmut↗
NASA NTRS1992

Experimental evaluation of candidate graphical microburst alert displays

A piloted flight simulator experiment has been conducted to evaluate issues related to the display of microburst alerts on electronic cockpit instrumentation. Issues addressed include display clarity, usefulness of multilevel microburst intensity information, and whether information from multiple sensors should be presented separately or 'fused' into combined alerts. Nine active airline pilots of 'glass-cockpit' aircraft participated in the study. Microburst alerts presented on a moving map display were found to be visually clear and useful to pilots. Also, multilevel intensity information coded by colors or patterns was found to be important for decision-making purposes. Inconclusive results were obtained on whether to 'fuse' data from multiple sensors. The positional information included in the graphical alert presentation was found useful by the pilots for planning lateral missed-approach maneuvers, but may result in deviations which could interfere with normal airport operations.

Wanke, Craig↗
NASA NTRS1991

A re-analysis of the causes of Boeing 727 'black hole landing' crashes

A review is presented of Kraft and Elworth's (1969) investigation and analysis of night visual approaches; their data is reanalyzed, and the reliability of the visual angle hypothesis is discussed. To increase pilot awareness of the hazardous illusions inherent in black hole landings, it was suggested that pilots should monitor their altimeters more often during night approaches. It was also recommended that greater attention should be given to airport design, so that the effects of black hole conditions could be minimized.

Schwirzke, Martin F. J.↗
NASA NTRS1991

Individual differences in strategic flight management and scheduling

A group of 30 instrument-rated pilots was made to fly simulator approaches to three airports under conditions of low, medium, and high workload conditions. An analysis is presently conducted of the difference in discrete task scheduling between the group of 10 highest and 10 lowest performing pilots in the sample; this categorization was based on the mean of various flight-profile measures. The two groups were found to differ from each other only in terms of the time when specific events were conducted, and of the optimality of scheduling for certain high-priority tasks. These results are assessed in view of the relative independence of task-management skills from aircraft-control skills.

Wickens, Christopher D.↗
NASA NTRS1992

Applied aerodynamics experience for secondary science teachers and students

The Department of Aerospace Engineering, Mechanics & Engineering Science at the University of Florida in conjunction with the Alachua County, Florida School Board has embarked on a four-year project of university-secondary school collaboration designed to enhance mathematics and science instruction in secondary school classrooms. The goals are to provide teachers with a fundamental knowledge of flight sciences, and to stimulate interest among students, particularly women and minorities, toward careers in engineering, mathematics, and science. In the first year of the project, all thirteen of the eighth grade physical science teachers and all 1200 of the eighth grade physical science students in the county participated. The activities consisted of a three-day seminar taught at the college level for the teachers, several weeks of classroom instruction for all the students, and an airport field trip for a subgroup of about 430 students that included an orientation flight in a Cessna 172 aircraft. The project brought together large numbers of middle school students, teachers, undergraduate and graduate engineering students, school board administrators, and university engineering faculty.

Abbitt, John D., III↗
NASA NTRS1993

MMIC Receiver For Water-Vapor Radiometer

MMIC receiver puts out signal, frequency of which proportioned to brightness temperature of sky at input frequency of 31 GHz. Miniaturization enhances thermal stability and stability of calibration of water-vapor radiometer. Potential for mass production at relatively low cost. Facilitating widespread use of MMIC water vapor radiometers in meteorology and aviation, deployed at several global sites to improve capability of general circulation models and at airports to monitor icing conditions by measuring supercooled liquid water in clouds.

Sukamto, Lin M.↗
NASA NTRS1992

A millimeter-wave radiometer for detecting microbursts

This paper describes a millimeter-wave radiometer for the detection of wind shear from airborne platforms or at airport terminals. This proposed instrument will operate near the group of atmospheric oxygen absorptions centered near 60 GHz, which it will use to sense temperature from a distance. The instrument will use two channels to provide two different temperature measurements, providing the basis for solution of two equations in two unknowns, which are range to the wind shear plume and its temperature. A third channel will measure ambient atmospheric temperature. Depending on the temperature difference between the wind-shear plume and ambient, the standard deviation of range measurement accuracy is expected to be about 1 km at 5 km range, while the temperature measurement standard deviation will be about one-fourth the temperature difference between plume and ambient at this range. The instrument is expected to perform usefully at ranges up to 10 km, giving adequate warning of the presence of wind shear even for high performance jet aircraft. Other atmospheric hazards which might be detected by this radiometer include aircraft wakes and vortices, clear-air turbulence, and wind rotors, although the latter two phenomena would be detected by an airborne version of the instrument. A separate radiometer channel will be provided in the proposed instrument to detect aircraft wakes and vortices based on perturbation of the spectrum of microscopic atmospheric temperature fluctuations caused by the passage of large aircraft.

Mcmillan, Robert↗
NASA NTRS1992

The Orlando TDWR testbed and airborne wind shear date comparison results

The focus of this talk is on comparing terminal Doppler Weather Radar (TDWR) and airborne wind shear data in computing a microburst hazard index called the F factor. The TDWR is a ground-based system for detecting wind shear hazards to aviation in the terminal area. The Federal Aviation Administration will begin deploying TDWR units near 45 airports in late 1992. As part of this development effort, M.I.T. Lincoln Laboratory operates under F.A.A. support a TDWR testbed radar in Orlando, FL. During the past two years, a series of flight tests has been conducted with instrumented aircraft penetrating microburst events while under testbed radar surveillance. These tests were carried out with a Cessna Citation 2 aircraft operated by the University of North Dakota (UND) Center for Aerospace Sciences in 1990, and a Boeing 737 operated by NASA Langley Research Center in 1991. A large data base of approximately 60 instrumented microburst penetrations has been obtained from these flights.

Campbell, Steven↗
NASA NTRS1992

Phoenix: Preliminary design of a high speed civil transport

The goal of the Phoenix Design Project was to develop a second generation high speed civil transport (HSCT) that will meet the needs of the traveler and airline industry beginning in the 21st century. The primary emphasis of the HSCT is to take advantage of the growing needs of the Pacific Basin and the passengers who are involved in that growth. A passenger load of 150 persons, a mission range of 5150 nautical miles, and a cruise speed of Mach 2.5 constitutes the primary design points of this HSCT. The design concept is made possible with the use of a well designed double delta wing and four mixed flow engines. Passenger comfort, compatibility with existing airport infrastructure, and cost competitive with current subsonic aircraft make the Phoenix a viable aircraft for the future.

Aguilar, Joseph↗
NASA NTRS1992

Eagle RTS: A design for a regional transport aircraft

This university design project concerns the Eagle RTS (Regional Transport System), a 66 passenger, twin turboprop aircraft with a range of 836 nautical miles. It will operate with a crew of two pilots and two flight attendents. This aircraft will employ the use of aluminum alloys and composite materials to reduce the aircraft weight and increase aerodynamic efficiency. The Eagle RTS will use narrow body aerodynamics with a canard configuration to improve performance. Leading edge technology will be used in the cockpit to improve flight handling and safety. The Eagle RTS propulsion system will consist of two turboprop engines with a total thrust of approximately 6300 pounds, 3150 pounds thrust per engine, for the cruise configuration. The engines will be mounted on the aft section of the aircraft to increase passenger safety in the event of a propeller failure. Aft mounted engines will also increase the overall efficiency of the aircraft by reducing the aircraft's drag. The Eagle RTS is projected to have a takeoff distance of approximately 4700 feet and a landing distance of 6100 feet. These distances will allow the Eagle RTS to land at the relatively short runways of regional airports.

Bryer, Paul↗
NASA NTRS1992

TBD(exp 3)

When asked by the Aeronautical Engineering staff to design a viable supersonic commercial transport, most of the students were well aware that Boeing, McDonnell Douglas, and other aircraft companies had been studying a cadre of transports for more than 30 years and had yet to present a viable aircraft. In the spirit of aviation progress and with much creative license, the TBD design team spearheaded the problem with the full intention of presenting a marketable high speed civil transport in spring of 1992. The project commenced with various studies of future market demands. With the market expansion of American business overseas, the airline industry projects a boom of over 200 million passengers by the year 2000. This will create a much higher demand for time efficient and cost effective inter-continental travel; this is the challenge of the high speed civil transport. The TBD(exp 3), a 269 passenger, long-range civil transport was designed to cruise at Mach 3.0 utilizing technology predicted to be available in 2005. Unlike other contemporary commercial airplane designs, the TBD(exp 3) incorporates a variable geometry wing for optimum performance. This design characteristic enabled the TBD(exp 3) to be efficient in both subsonic and supersonic flight. The TBD(exp 3) was designed to be economically viable for commercial airline purchase, be comfortable for passengers, meet FAR Part 25, and the current FAR 36 Stage 3 noise requirements. The TBD(exp 3) was designed to exhibit a long service life, maximize safety, ease of maintenance, as well as be fully compatible with all current high-traffic density airport facilities.

Baughan, Jim↗
NASA NTRS1992

A second-generation high speed civil transport: Stingray

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.

Engdahl, Sean↗