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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 523 records · Page 29
All sourcesNASA NTRSDOE OSTI
NASA NTRS1956

Performance of variable two-dimensional inlet designed for engine-inlet matching I : performance at design Mach number of 3.07

The inlet was investigated with both a two-oblique-shock and an isentropic compression ramp. Provisions for a variety of bypass systems were incorporated and none decreased pressure recovery by more than about 1 percent. By utilizing throat boundary-layer control, critical pressure recoveries of 64 and 70 percent were obtained with the two-shock and isentropic ramps, respectively. Diffuser-exit air distortion was about 5 percent at critical operation Theoretical cowl pressure drag was equal to about 10 percent of the net thrust of an assumed engine.

Beheim, M A↗
NASA NTRS2005

Turbofan Noise Reduction Associated With Increased Bypass Nozzle Flow

An advanced 22-in. scale model turbofan, typical of a current-generation aircraft engine design by GE Aircraft Engines, was tested in NASA Glenn Research Center s 9- by 15- Foot Low-Speed Wind Tunnel to explore the far-field acoustic effects of an increased bypass nozzle area at simulated aircraft speeds of takeoff, approach, and landing. The wind-tunnel-scale model consisted of the bypass stage fan, stators, and nacelle (including the fan exit nozzle) of a typical turbofan. This fan-stage test was part of the NASA Glenn Fan Broadband Source Diagnostic Test, second entry, which acquired aeroacoustic results over a range of test conditions. A baseline nozzle was selected, and the nozzle area was chosen for maximum performance at sea-level conditions. Two additional nozzles were also tested--one with a 5.4-percent increase in nozzle area over the baseline nozzle (sized for design point conditions), corresponding to a 5-percent increase in fan weight flow, and another nozzle with a 10.9-percent increase in nozzle area over the baseline nozzle (sized for maximum weight flow at sea-level conditions), corresponding to a 7.5 percent increase in fan weight flow. Measured acoustic benefits with increased nozzle area were very encouraging, showing overall sound power level reductions of 2 dB or more (left graph) while the stage adiabatic efficiency (right graph) and thrust (final graph) actually increased by several percentage points. These noise-reduction benefits were seen to include both rotor-interaction tones and broadband noise, and were evident throughout the range of measured sideline angles.

Woodward, Richard P.↗
NASA NTRS1977

The Role of Aerospace Technology in Agriculture. The 1977 Summer Faculty Fellowship Program in Engineering Systems Design

Possibilities were examined for improving agricultural productivity through the application of aerospace technology. An overview of agriculture and of the problems of feeding a growing world population are presented. The present state of agriculture, of plant and animal culture, and agri-business are reviewed. Also analyzed are the various systems for remote sensing, particularly applications to agriculture. The report recommends additional research and technology in the areas of aerial application of chemicals, of remote sensing systems, of weather and climate investigations, and of air vehicle design. Also considered in detail are the social, legal, economic, and political results of intensification of technical applications to agriculture.

Source record↗
NASA NTRS1978

Energy efficient engine: Preliminary design and integration studies

A mixed exhaust, direct drive fan turbofan configuration was selected from four candidates. This choice was based on its ability to exceed study goals of 12% lower thrust specific fuel consumption and 5% lower direct operating cost by the 1990's with commercially acceptable technical risk and relative mechanical simplicity. The evaluation leading to configuration selection is discussed. Necessary technology advancements are identified and related to the goals.

Gray, D. E.↗
NASA NTRS1978

Air cargo: An Integrated Systems View. 1978 Summer Faculty Fellowship Program in Engineering Systems Design

The national air cargo system is analyzed and how it should be in 1990 is prescribed in order to operate successfully through 2015; that is through one equipment cycle. Elements of the system which are largely under control of the airlines and the aircraft manufacturers are discussed. The discussion deals with aircraft, networks, facilities, and procedures. The regulations which govern the movement of air freight are considered. The larger public policy interests which must be served by the kind of system proposed, the air cargo integrated system (ACIS), are addressed. The possible social, economical, political, and environment impacts of the system are considered. Recommendations are also given.

Keaton, A.↗
NASA NTRS1984

Engineering and design properties of thallium-doped sodium iodide and selected properties of sodium-doped cesium iodide

Mechanical and thermal properties, not available in the literature but necessary to structural design, using thallium doped sodium iodide and sodium doped cesium iodide were determined to be coefficient of linear thermal expansion, thermal conductivity, thermal shock resistance, heat capacity, elastic constants, ultimate strengths, creep, hardness, susceptibility to subcritical crack growth, and ingot variation of strength. These properties were measured for single and polycrystalline materials at room temperature.

Forrest, K.↗
NASA NTRS1989

Engineering sciences design. Design and implementation of components for a bioregenerative system for growing higher order plants in space

The primary goal was to address specific needs in the design of an integrated system to grow higher plants in space. With the needs defined, the emphasis was placed on the design and fabrication of devices to meet these needs. Specific attention was placed on a hand-held harvester, a nutrient concentration sensor, an air-water separator, and a closed-loop biological system simulation.

Nevill, Gale E., Jr.↗
NASA NTRS1990

Progress in hypersonic combustion technology with computation and experiment

Design of successful airbreathing engines for operation at near-orbital speeds presents significant challenges in all the disciplines involved, including propulsion. This paper presents a discussion of the important physics of hypersonic combustion and an assessment of the state of the art of ground simulations with pulse facilities and with computational techniques. Recent examples of experimental and computational simulations are presented and discussed. The need for continued application of these tools to establish the credibility and fidelity of engineering design methods for practical hypersonic combustors is emphasized along with the critical need for improved diagnostic methods for hypervelocity reacting flows.

Anderson, Griffin Y.↗
NASA NTRS1991

NTR vehicle commonality assessment for piloted lunar and Mars missions

A study is presented that assesses the feasibility of (1) using common nuclear thermal rocket (NTR) vehicle components to perform a wide range of lunar and Mars missions, and (2) potential performance gains achieved via 'dual-mode' NTR operation, where the nuclear reactor is utilized not only for propulsion but also for electrical power generation. Four vehicle configurations are considered, modular designs with multiple single engine modules and single engine designs with multiple propellant tanks. The standard tank sizes arrived at in the Mars mission mass performance calculations are then applied to cargo and piloted lunar craft to evaluate lunar NTR mass performance against that for chemical propulsion.

Collins, John T.↗
NASA NTRS1992

Practical considerations in designing the engine cycle

When it is required to define the cycle parameters and calculate the performance of a real engine, there are numerous practical constraints that need to be taken into account. These fall into two main categories: the limitations of available component technologies, and the operational considerations that are dependent on aircraft application. The lecture discusses the main technology limiters and indicates how they are incorporated into the cycle definition process. Operational factors include the extent of the intended flight envelope and range of critical flight conditions for which performance must be assured, and the balance to be struck between minimising fuel consumption, maximising installed power and constraining costs of ownership. Taking these technology and operational influences into account, the basic cycle characteristics and approach to cycle choice are examined for three main classes of aircraft: subsonic transports, military combat aircraft and helicopters.

M G Philpot↗