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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 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Propulsion evaluation for orbit-on-demand vehicles

Future earth-to-orbit vehicles may be required to reach orbit within hours or even minutes of a decision. A study has been conducted to consider vehicles with such a capability. In Phase I of the study, 11 vehicles were designed to deploy 5000 lb to a polar orbit. Changes in the designs were examined parametrically for increased on-orbit maneuvers, increased payload, and other mission variations. Based on the results, two concepts were selected for Phase II design work: a vertical-takeoff, two-stage system and a horizontal-takeoff, two-stage system with an airbreathing subsonic first stage. The results of several propulsion evaluations are presented, including liftoff thrust-to-weight effects, dual-fuel propulsion for a horizontal-takeoff concept, and the effect of using fluorine.

Martin, J. A.↗
NASA NTRS1986

Static internal performance of a thrust vectoring and reversing two-dimensional convergent-divergent nozzle with an aft flap

The static internal performance of a multifunction nozzle having some of the geometric characteristics of both two-dimensional convergent-divergent and single expansion ramp nozzles has been investigated in the static-test facility of the Langley 16-Foot Transonic Tunnel. The internal expansion portion of the nozzle consisted of two symmetrical flat surfaces of equal length, and the external expansion portion of the nozzle consisted of a single aft flap. The aft flap could be varied in angle independently of the upper internal expansion surface to which it was attached. The effects of internal expansion ratio, nozzle thrust-vector angle (-30 deg. to 30 deg., aft flap shape, aft flap angle, and sidewall containment were determined for dry and afterburning power settings. In addition, a partial afterburning power setting nozzle, a fully deployed thrust reverser, and four vertical takeoff or landing nozzle, configurations were investigated. Nozzle pressure ratio was varied up to 10 for the dry power nozzles and 7 for the afterburning power nozzles.

Re, R. J.↗
NASA NTRS1986

Two-stage earth-to-orbit vehicles with series and parallel burn

Recent studies have indicated that a fully reusable earth-to-orbit vehicle system will be needed near the beginning of the next century. One likely concept is a two-stage, vertical takeoff system with liquid rocket propulsion. Such vehicles have been examined with series burn and parallel burn of the engines of each stage. The results indicate that the preferred concept will have parallel burn with crossfeed, the booster will have hydrocarbon engines, the Orbiter will have both hydrocarbon and hydrogen engines, and the staging velocity will be low enough to allow the booster to glide back to the launch site.

Martin, J. A.↗
NASA NTRS1987

Laser Doppler Velocimeter measurements in a 3-D impinging twin-jet fountain flow

Mean velocity and turbulence measurements were conducted on the three dimensional fountain flow field generated by the impingement of two axisymmetric jets on a ground plane with application to vertical takeoff and landing (VTOL) aircraft. The basic instantaneous velocity data were obtained using a two component laser Doppler velocimeter in a plane connecting the nozzle centerlines at different heights above the ground emphasizing the jet impingement region and the fountain upwash region formed by the collision of the wall jets. The distribution of mean velocity components and turbulence quantities, including the turbulence intensity and the Reynolds shear stress, were derived from the basic velocity data. Detailed studies of the characteristics of the fountain revealed self-similarity in the mean velocity and turbulence profiles across the fountain. The spread and mean velocity decay characteristics of the fountain were established. Turbulence intensities of the order of 50% were observed in the fountain.

Saripalli, K. R.↗
NASA NTRS1987

Hot gas ingestion: From model results to full scale engine testing

An overview is presented of a joint NASA Lewis McDonnell Aircraft Co. Hot Gas Ingestion (HGI) test program in NASA Lewis' 9 x 15 foot Low Speed Wind Tunnel (LSWT). Advanced short takeoff vertical landing (ASTOVL) aircraft capable of operating from remote sites, damaged runways, aircraft carriers and small air-capable ships are being pursued for deployment around the turn of the century. To achieve this goal, it is important that technologies critical to this unique class of aircraft be developed. One of the ASTOVL concepts, the vectored thrust, has as its critical technology item, the potential of hot gas ingestion (which occurs during vertical flight operation while in ground effect) as a key development issue. Recognizing this need, NASA Lewis Powered Lift Section and McAir have defined a cooperative program for testing in the Lewis 9 x 15 foot LSWT. This program is described in detail.

Johns, Albert L.↗
NASA NTRS1986

Advanced manned earth-to-orbit vehicle

Advanced manned launch vehicle concepts which are designed to meet the space transportation architecture and mission needs for the early 21st century are described. Concepts are described which are based both on modest (evolutionary) and revolutionary advancements in performance technologies but with emphasis on defining operations cost. Design options feature fully reusable, vertical-takeoff, horizontal-landing, rocket-powered concepts and include a variety of possible staging arrangements depending on the desired mission emphasis and the available technologies.

Eldred, Charles H.↗
NASA NTRS1987

The effects of aeroelastic deformation on the unaugmented stopped-rotor dynamics of an X-Wing aircraft

A new design concept in the development of vertical takeoff and landing aircraft with high forward flight speed capability is that of the X-Wing. The X-Wing is a stiff, bearingless helicopter rotor system which can be stopped in flight and the blades used as two forward-swept wings and two aft-swept wings. Because of the unusual configuration in the fixed-wing mode, there is a high potential for aeroelastic divergence or flutter and coupling of blade vibration modes with rigid-body modes. An aeroelastic stability analysis of an X-Wing configuration aircraft was undertaken to determine if these problems could exist. This paper reports on the results of dynamic stability analyses in the lateral and longitudinal directions including the vehicle rigid-body and flexible modes. A static aeroelastic analysis using the normal vibration mode equations of motion was performed to determine the cause of a loss of longitudinal static margin with increasing airspeed. This loss of static margin was found to be due to aeroelastic 'washin' of the forward-swept blades and 'washout' of the aft-swept blades moving the aircraft aerodynamic center forward of the center of gravity. This phenomenon is likely to be generic to X-Wing aircraft.

Gilbert, Michael G.↗
NASA NTRS1988

Research On The CH-47B Helicopter

Report describes equipment added to, and research capabilities of CH-47B helicopter. Programmable symbol generator provides display formats for variety of missions - those of vertical-takeoff-and-landing aircraft and helicopters. Powerful general-purpose flight computer in operation. Computer programmable in high-level languages and supports research more efficiently. Flight-control software developed to improve capability of helicopter to perform simulations in flight.

Hilbert, Kathryn B.↗
NASA NTRS1987

Flight propulsion control integration for V/STOL aircraft

The goal of the propulsion community is to have the enabling propulsion technologies in place to permit a low risk decision regarding the initiation of a research STOVL supersonic attack fighter aircraft in the mid-1990's. This technology will effectively integrate, enhance, and extend the supersonic cruise, STOVL, and fighter/attack programs to enable U.S. industry to develop a revolutionary supersonic short takeoff vertical landing fighter/attack aircraft in the post-ATF period. The rationale, methods, and criteria used in developing a joint NASA Lewis and NASA Ames research program to develop the technology element for integrated flight propulsion control through integrated methodologies is presented. This program, the Supersonic STOVL Integrated Flight Propulsion Controls Program, is part of the overall NASA Lewis Supersonic STOVL integrated approach to an integrated program to achieve integrated flight propulsion control technology.

Mihaloew, James R.↗
NASA NTRS1988

A numerical study of the hot gas environment around a STOVL aircraft in ground proximity

The development of Short Takeoff Vertical Landing (STOVL) aircraft has historically been an empirical- and experience-based technology. In this study, a 3-D turbulent flow CFD code was used to calculate the hot gas environment around an STOVL aircraft operating in ground proximity. Preliminary calculations are reported for a typical STOVL aircraft configuration to identify key features of the flow field, and to demonstrate and assess the capability of current 3-D CFD codes to calculate the temperature of the gases ingested at the engine inlet as a function of flow and geometric conditions.

Vanoverbeke, Thomas J.↗
NASA NTRS1988

Flight testing a V/STOL aircraft to identify a full-envelope aerodynamic model

Flight-test techniques are being used to generate a data base for identification of a full-envelope aerodynamic model of a V/STOL fighter aircraft, the YAV-8B Harrier. The flight envelope to be modeled includes hover, transition to conventional flight and back to hover, STOL operation, and normal cruise. Standard V/STOL procedures such as vertical takeoff and landings, and short takeoff and landings are used to gather data in the powered-lift flight regime. Long (3 to 5 min) maneuvers which include a variety of input types are used to obtain large-amplitude control and response excitations. The aircraft is under continuous radar tracking; a laser tracker is used for V/STOL operations near the ground. Tracking data are used with state-estimation techniques to check data consistency and to derive unmeasured variables, for example, angular accelerations. A propulsion model of the YAV-8B's engine and reaction control system is used to isolate aerodynamic forces and moments for model identification. Representative V/STOL flight data are presented. The processing of a typical short takeoff and slow landing maneuver is illustrated.

Mcnally, B. David↗
NASA NTRS1987

Shuttle II

This paper presents a status report on the study of a next-generation manned launch system, called Shuttle II, being conducted at the NASA Langley Research Center. Underlying reasons for considering such a system include the need for low-cost, safe, and reliable manned access to space. System and operational characteristics for a Shuttle II vehicle are presented. The need for fully reusable launch systems with radically simpler ground and flight operations is stated to be critical in reducing launch costs. Advancing technologies have a major impact on the choice of vehicle concepts. For a near-term level of technology, a two-stage vertical-takeoff rocket vehicle has been selected for further in-depth Shuttle II studies. The role of the Shuttle II vehicle in a proposed space transportation system, which includes heavy lift and Space Shuttle complementary manned systems, is discussed.

Talay, T. A.↗
NASA NTRS1988

Flight propulsion control integration for V/STOL aircraft

The goal of the propulsion community is to have the enabling propulsion technologies in place to permit a low risk decision regarding the initiation of a research STOVL supersonic attack fighter aircraft in the mid-1990's. This technology will effectively integrate, enhance, and extend the supersonic cruise, STOVL, and fighter/attack programs to enable U.S. industry to develop a revolutionary supersonic short takeoff vertical landing fighter/attack aircraft in the post-ATF period. The rationale, methods, and criteria used in developing a joint NASA Lewis and NASA Ames research program to develop the technology element for integrated flight propulsion control through integrated methodologies is presented. This program, the Supersonic STOVL integrated Flight Propulsion Controls Program, is part of the overall NASA Lewis Supersonic STOVL integrated approach to an integrated program to achieve integrated flight propulsion control technology.

Mihaloew, James R.↗
NASA NTRS1988

Flight testing a V/STOL aircraft to identify a full-envelope aerodynamic model

Flight-test techniques are being used to generate a data base for identification of a full-envelope aerodynamic model of a V/STOL fighter aircraft, the YAV-8B Harrier. The flight envelope to be modeled includes hover, transition to conventionally flight and back to hover, STOL operation, and normal cruise. Standard V/STOL operation, and normal cruise. Standard V/STOL procedures such as vertical takeoff and landings, and short takeoff and landings are used to gather data in the powered-lift flight regime. Long (3-5-min) maneuvers which include a variety of input types are used to obtain large-amplitude control and response excitations. The aircraft is under continuous radar tracking; a laser tracker is used for V/STOL operations near the ground. Tracking data are used with state-estimation techniques to check data consistency and to derive unmeasured variables, for example, angular accelerations. A propulsion model of the YAV-8B's engine and reaction control system is used to isolate aerodynamic forces and moments for model identification. Representative V/STOL flight data are presented. The processing of a typical short-takeoff and slow-landing maneuver is illustrated.

Mcnally, B. David↗
NASA NTRS1988

Evaluation of innovative rocket engines for single-stage earth-to-orbit vehicles

Computer models of rocket engines and single-stage-to-orbit vehicles that were developed by the authors at DFVLR and NASA have been combined. The resulting code consists of engine mass, performance, trajectory and vehicle sizing models. The engine mass model includes equations for each subsystem and describes their dependences on various propulsion parameters. The engine performance model consists of multidimensional sets of theoretical propulsion properties and a complete thermodynamic analysis of the engine cycle. The vehicle analyses include an optimized trajectory analysis, mass estimation, and vehicle sizing. A vertical-takeoff, horizontal-landing, single-stage, winged, manned, fully reusable vehicle with a payload capability of 13.6 Mg (30,000 lb) to low earth orbit was selected. Hydrogen, methane, propane, and dual-fuel engines were studied with staged-combustion, gas-generator, dual bell, and the dual-expander cycles. Mixture ratio, chamber pressure, nozzle exit pressure liftoff acceleration, and dual fuel propulsive parameters were optimized.

Manski, Detlef↗
NASA NTRS1988

A numerical study of the hot gas environment around a STOVL aircraft in ground proximity

The development of Short Takeoff Vertical Landing (STOVL) aircraft has historically been an empirical- and experience-based technolgoy. In this study, a 3-D turbulent flow CFD code was used to calculate the hot gas environment around an STOVL aircraft operating in ground proximity. Preliminary calculations are reported for a typical STOVL aircraft configuration to identify key features of the flow field, and to demonstrate and assess the capability of current 3-D CFD codes to calculate the temperature of the gases ingested at the engine inlet as a function of flow and geometric conditions.

Vanoverbeke, Thomas J.↗
NASA NTRS1984

Experimental results for a two-dimensional supersonic inlet used as a thrust deflecting nozzle

Nearly all supersonic V/STOL aircraft concepts are dependent on the thrust deflecting capability of a nozzle. In one unique concept, referred to as the reverse flow dual fan, not only is there a thrust deflecting nozzle for the fan and core engine exit flow, but because of the way the propulsion system operates during vertical takeoff and landing, the supersonic inlet is also used as a thrust deflecting nozzle. This paper presents results of an experimental study to evaluate the performance of a supersonic inlet used as a thrust deflecting nozzle for this reverse flow dual fan concept. Results are presented in terms of nozzle thrust coefficient and thrust vector angle for a number of inlet/nozzle configurations. Flow visualization and nozzle exit flow survey results are also shown.

Johns, Albert L.↗
NASA NTRS1989

Advanced Manned Launch Systems

Advanced Manned Launch Systems (AMLS) studies underway at the NASA Langley Research Center are part of a broader effort examining options for the next U.S. manned space transportation system. AMLS study phases have focused on investigating mission needs and identifying technologies and technology levels, concepts, systems, operational requirements, and life-cycle costs. For near-term technologies and an operations-oriented approach, two-stage vertical-takeoff rocket vehicles with significant levels of reusability are shown to be cost-effective for moderate to high flight rates. All-hydrogen fuel vehicles are also preferred over methane boosted systems from both operational and cost considerations.

Talay, Theodore A.↗