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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.

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At least 325 records · Page 18
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NASA NTRS1978

Load and dynamic assessment of B-52B-008 carrier aircraft for finned configuration 1 space shuttle solid rocket booster decelerator subsystem drop test vehicle. Volume 2: Airplane flutter and load analysis results

The airplane flutter and maneuver-gust load analysis results obtained during B-52B drop test vehicle configuration (with fins) evaluation are presented. These data are presented as supplementary data to that given in Volume 1 of this document. A brief mathematical description of airspeed notation and gust load factor criteria are provided as a help to the user. References are defined which provide mathematical description of the airplane flutter and load analysis techniques. Air-speed-load factor diagrams are provided for the airplane weight configurations reanalyzed for finned drop test vehicle configuration.

Quade, D. A.↗
NASA NTRS1978

Feasibility of wing shielding of the airplane interior from the shock noise generated by supersonic tip speed propellers

A high tip speed turboprop is being considered as a future energy conservative airplane. The high tip speed of the propeller, combined with the speed of the airplane, results in supersonic relative flow on the propeller tips. These supersonic blade sections could generate noise that is a cabin environment problem. The feasibility of using wing shielding to lessen the impact of this supersonic propeller noise was investigated. An analytical model is chosen which considers that shock waves are associated with the propeller tip flow and indicates how they would be prevented from impinging on the airplane fuselage. An example calculation is performed where a swept wing is used to shield the fuselage from significant portions of the propeller shock waves.

Dittmar, J. H.↗
NASA NTRS1979

Low-speed wind-tunnel investigation of wing fins as trailing-vortex-alleviation devices on a transport airplane model

The trailing-vortex-alleviation effectiveness of both a one- and a two-fin configuration (semicircular with a radius of 0.043 semispan) on a jumbo-jet transport airplane model in its landing configuration was investigated in the Langley V/STOL tunnel, by the trailing-wing sensor technique. The fins were located on the upper surface of the transport model wing along the 30-percent-chord line. The fin configurations were effective in reducing the vortex-induced rolling moment, by amounts varying from 28 to 60 percent, on the trailing wing model located at a distance of 7.8 transport model wing spans downstream of the transport model. The flow over the fins and over the transport airplane model wing downstream of the fins was observed to be separated and turbulent. All fin configurations caused a reduction in maximum lift coefficient, a positive increment in drag coefficient, and an increment in nose-up pitching-moment coefficient on the transport airplane model.

Croom, D. R.↗
NASA NTRS1979

Laboratory study of annoyance to combined airplane and road-traffic noise

The annoyance of noise, which consisted of both separate and combined airplane and road-traffic noises, was studied. The subjects judged each session as to how annoyed they were in the simulated living room laboratory environment and as to how annoyed they were if they heard the noise in their home during day, evening, and night periods. The airplane noises, for equal session levels were judged significantly more annoying than the road traffic noises for the separate sessions. For the combined sessions, an interaction was found between the airplane noise and traffic noise levels, which was not adequately assessed by the total energy concept. Significant differences were found between the projected home responses for the day, evening, and night periods.

Powell, C. A.↗
NASA NTRS1975

Flight determined lift and drag characteristics of an F-8 airplane modified with a supercritical wing with comparison to wind-tunnel results

Flight measurements obtained with a TF-8A airplane modified with a supercritical wing are presented for altitudes from 7.6 kilometers (25,000 feet) to 13.7 kilometers (45,000 feet), Mach numbers from 0.6 to 1.2, and Reynolds numbers from 0.8 x 10 to the 7th power to 2.3 x 10 to the 7th power. Flight results for the airplane with and without area-rule fuselage fairings are compared. The techniques used to determine the lift and drag characteristics of the airplane are discussed. Flight data are compared with wind-tunnel model results, where applicable.

Pyle, J. S.↗
NASA NTRS1979

A Mars airplane

An airplane specifically designed for Mars flight is described, emphasizing its conceivable role as an aerial surveyor for visual imaging, gamma-ray and IR reflectance spectroscopy, studies of atmospheric composition and dynamics, and gravity-field, magnetic-field, and electromagnetic sounding. Possible imaging systems and surveying tasks are considered, along with a plausible mission scenario for a fleet of 12 airplanes, which would be taken to Mars in squadrons of four by three Shuttle/IUS Twin Stage/spacecraft carriers. A basic configuration closely resembling that of a competition glider is examined, and four types of airplane are discussed: hydrazine-powered cruisers and landers and electrically powered cruisers and landers. Attention is given to navigation, guidance, and control avionics, vehicle weight, the use of composite materials for the wing, and flight testing on earth.

Clarke, V. C.↗
NASA NTRS1979

A Mars Airplane . . . Oh really

This paper describes the mission design, scientific utilization, and prototypical design of a Mars Airplane. As a scientific platform, the airplane provides an excellent means of obtaining data in a resolution range intermediate to surface vehicles and orbiters. It has great versatility to perform a variety of missions: conduct aerial surveys, land instrument packages, collect samples, and perform atmospheric sounding. The Mars Airplane has many characteristics of a competition glider on earth. Two versions of the plane, a cruiser, and one with soft landing and takeoff capability, have been designed. Maximum range and endurance are 10,000 km and 31.1 hours with a 40-kg payload.

Clarke, V. C., Jr.↗
NASA NTRS1979

Some theoretical considerations of a stall proof airplane

For the stall proof airplane there should be a stabilizing pitching moment below the stall angle of attack of sufficient amount to prevent the attainment of the stall angle of attack which cannot be over-ridden by control deflections. This paper presents (1) a development of the moment equations to show the theoretical considerations of a stall proof airplane and (2) the nonlinear moment characteristics that must be obtained to satisfy the stall proof requirements. In addition, it is shown that an aerodynamic spoiler located on the under surface of the horizontal tail can be designed to meet these requirements of a stall proof airplane. Wind tunnel results are shown to validate assumptions and predictions.

Chevalier, H. L.↗
NASA NTRS1979

Simulator study of stall/post-stall characteristics of a fighter airplane with relaxed longitudinal static stability

A real-time piloted simulation was conducted to evaluate the high-angle-of-attack characteristics of a fighter configuration based on wind-tunnel testing of the F-16, with particular emphasis on the effects of various levels of relaxed longitudinal static stability. The aerodynamic data used in the simulation was conducted on the Langley differential maneuvering simulator, and the evaluation involved representative low-speed combat maneuvering. Results of the investigation show that the airplane with the basic control system was resistant to the classical yaw departure; however, it was susceptible to pitch departures induced by inertia coupling during rapid, large-amplitude rolls at low airspeed. The airplane also exhibited a deep-stall trim which could be flown into and from which it was difficult to recover. Control-system modifications were developed which greatly decreased the airplane susceptibility to the inertia-coupling departure and which provided a reliable means for recovering from the deep stall.

Nguyen, L. T.↗
NASA NTRS1980

A spin-recovery parachute system for light general-aviation airplanes

A tail mounted spin recovery parachute system was designed and developed by the NASA Langley Research Center for use on light general aviation airplanes. The system was designed for use on typical airplane configurations, including low wing, single engine, and twin-engine design. A mechanically triggered pyrotechnic slug gun is used to forcibly deploy a pilot parachute which extracts a bag that deploys a ring slot spin recovery parachute. The total system weighs 8.2 kg (18 lb). System design factors included airplane wake effects on parachute deployment, prevention of premature parachute deployment, positive parachute jettison, compact size, low weight, system reliability, and pilot and ground crew safety. Extensive ground tests were conducted to qualify the system. The recovery parachute was used successfully in flight 17 times.

Bradshaw, C.↗
NASA NTRS1980

A spin-recovery parachute system for light general-aviation airplanes

A tail mounted spin recovery parachute system was designed and developed for use on light general aviation airplanes. The system was designed for use on typical airplane configurations, including low wing, high wing, single engine and twin engine designs. A mechanically triggered pyrotechnic slug gun is used to forcibly deploy a pilot parachute which extracts a bag that deploys a ring slot spin recovery parachute. The total system weighs 8.2 kg. System design factors included airplane wake effects on parachute deployment, prevention of premature parachute deployment, positive parachute jettison, compact size, low weight, system reliability, and pilot and ground crew safety. Extensive ground tests were conducted to qualify the system. The recovery parachute was used successfully in flight 17 times.

Bradshaw, C.↗
NASA NTRS1980

Maximum likelihood method for estimating airplane stability and control parameters from flight data in frequency domain

A frequency domain maximum likelihood method is developed for the estimation of airplane stability and control parameters from measured data. The model of an airplane is represented by a discrete-type steady state Kalman filter with time variables replaced by their Fourier series expansions. The likelihood function of innovations is formulated, and by its maximization with respect to unknown parameters the estimation algorithm is obtained. This algorithm is then simplified to the output error estimation method with the data in the form of transformed time histories, frequency response curves, or spectral and cross-spectral densities. The development is followed by a discussion on the equivalence of the cost function in the time and frequency domains, and on advantages and disadvantages of the frequency domain approach. The algorithm developed is applied in four examples to the estimation of longitudinal parameters of a general aviation airplane using computer generated and measured data in turbulent and still air. The cost functions in the time and frequency domains are shown to be equivalent; therefore, both approaches are complementary and not contradictory. Despite some computational advantages of parameter estimation in the frequency domain, this approach is limited to linear equations of motion with constant coefficients.

Klein, V.↗
NASA NTRS1980

A spin-recovery parachute system for light general aviation airplanes

A tail-mounted spin-recovery parachute system has been designed and developed by the NASA Langley Research Center for use on light general aviation airplanes. The system was designed for use on typical airplane configurations, including low-wing, high-wing, single- and twin-engine designs. A mechanically triggered pyrotechnic slug gun is used to forcibly deploy a pilot parachute which extracts a bag that deploys a ring-slot spin-recovery parachute. The total system weighs 8.2 kg (18 lb). System design factors included airplane wake effects on parachute deployment, prevention of premature parachute deployment, positive parachute jettison, compact size, low weight, system reliability, and pilot and ground crew safety. Extensive ground tests were conducted to qualify the system. The recovery parachute has been used successfully in flight 17 times.

Bradshaw, C. F.↗
NASA NTRS1980

Flight evaluation of the effect of winglets on performance and handling qualities of a single-engine general aviation airplane

A flight evaluation was conducted to determine the effects of winglets on the performance and handling qualities of a light, single-engine general aviation airplane. The performance measurements were made with a pace airplane to provide calibrated airspeeds; uncalibrated panel instruments in the test airplane were used to provide additional quantitative performance data. These tests were conducted with winglets on and off during the same day to measure relative performance effects. Handling qualities were evaluated by means of pilot comments. Winglets increased cruise speed 8 knots (5.6 percent) at 3962 m (13,000 ft) density altitude and 51 percent maximum continuous power setting. Maximum speed at 3962 m was virtually unchanged. Rate of climb increased approximately 6 percent, or 0.25 m/sec (50 ft/min), at 1524 m (5000 ft). Stall speed was virtually unchanged. Handling qualities were favorably affected.

Holmes, B. J.↗
NASA NTRS1980

Bird flight and airplane flight

Research was based on a series of mechanical, electrical, and cinematographic instruments developed to measure various features of air current behavior as well as bird and airplane flight. Investigation of rising obstruction and thermal currents led to a theory of bird flight, especially of the gliding and soaring types. It was shown how a knowledge of bird flight can be applied to glider and ultimately motorized aircraft construction. The instruments and methods used in studying stress in airplanes and in comparing the lift to drag ratios of airplanes and birds are described.

Magnan, A.↗
NASA NTRS1981

MLS: Airplane system modeling

Analysis, modeling, and simulations were conducted as part of a multiyear investigation of the more important airplane-system-related items of the microwave landing system (MLS). Particular emphasis was placed upon the airplane RF system, including the antenna radiation distribution, the cabling options from the antenna to the receiver, and the overall impact of the airborne system gains and losses upon the direct-path signal structure. In addition, effort was expended toward determining the impact of the MLS upon the airplane flight management system and developing the initial stages of a fast-time MLS automatic control system simulation model. Results ot these studies are presented.

Thompson, A. D.↗
NASA NTRS1981

Application of a performance modeling technique to an airplane with variable sweep wings

A performance modeling concept previously applied to an F-104F G and a YF-12C airplane was applied to an F-111A airplane. This application extended the concept to an airplane with variable sweep wings. The performance model adequately matched flight test data for maneuvers flown at different wing sweep angles at maximum afterburning and intermediate power settings. For maneuvers flown at less than intermediate power, including dynamic maneuvers, the performance model was not validated because the method used to correlate model and in-flight power setting was not adequate. Individual dynamic maneuvers were matched sucessfully by using adjustments unique to each maneuver.

Redin, P. C.↗
NASA NTRS1981

Aerodynamic design data for a cruise-matched high performance single-engine airplane

Design data are presented for a class of high-performance single-engine business airplanes. The design objectives include a cruise speed of 300 knots, a cruise altitude of 10,700 m (35,000 ft), a cruise payload of six passengers (including crew and baggage), and a no-reserves cruise range of 1300 n.mi. Two unconventional aerodynamic technologies were evaluated: the individual and combined effects of cruise-matched wing loading and of a natural laminar flow airfoil were analyzed. The trade-off data presented illustrate the ranges of wing geometries, propulsion requirements, airplane weights, and aerodynamic characteristics which are necessary to meet the design objectives. Very large design and performance improvements resulted from use of the aerodynamic technologies evaluated. It is shown that the potential exists for achieving more than 200-percent greater fuel efficiency than is achieved by current airplanes capable of similar cruise speeds, payloads, and ranges.

Holmes, B. J.↗