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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 127 records · Page 7

Hyper-X Mach 7 Scramjet Design, Ground Test and Flight Results

The successful Mach 7 flight test of the Hyper-X (X-43) research vehicle has provided the major, essential demonstration of the capability of the airframe integrated scramjet engine. This flight was a crucial first step toward realizing the potential for airbreathing hypersonic propulsion for application to space launch vehicles. However, it is not sufficient to have just achieved a successful flight. The more useful knowledge gained from the flight is how well the prediction methods matched the actual test results in order to have confidence that these methods can be applied to the design of other scramjet engines and powered vehicles. The propulsion predictions for the Mach 7 flight test were calculated using the computer code, SRGULL, with input from computational fluid dynamics (CFD) and wind tunnel tests. This paper will discuss the evolution of the Mach 7 Hyper-X engine, ground wind tunnel experiments, propulsion prediction methodology, flight results and validation of design methods.

Ferlemann, Shelly M.↗

The Hyper-X Flight Systems Validation Program

For the Hyper-X/X-43A program, the development of a comprehensive validation test plan played an integral part in the success of the mission. The goal was to demonstrate hypersonic propulsion technologies by flight testing an airframe-integrated scramjet engine. Preparation for flight involved both verification and validation testing. By definition, verification is the process of assuring that the product meets design requirements; whereas validation is the process of assuring that the design meets mission requirements for the intended environment. This report presents an overview of the program with emphasis on the validation efforts. It includes topics such as hardware-in-the-loop, failure modes and effects, aircraft-in-the-loop, plugs-out, power characterization, antenna pattern, integration, combined systems, captive carry, and flight testing. Where applicable, test results are also discussed. The report provides a brief description of the flight systems onboard the X-43A research vehicle and an introduction to the ground support equipment required to execute the validation plan. The intent is to provide validation concepts that are applicable to current, follow-on, and next generation vehicles that share the hybrid spacecraft and aircraft characteristics of the Hyper-X vehicle.

Redifer, Matthew↗

NESC Review of the 8-Foot High Temperature Tunnel (HTT) Oxygen Storage Pressure Vessel Inspection Requirements

The 8-Foot HTT (refer to Figure 4.0-1) is used to conduct tests of air-breathing hypersonic propulsion systems at Mach numbers 4, 5, and 7. Methane, Air, and LOX are mixed and burned in a combustor to produce test gas stream containing 21 percent by volume oxygen. The NESC was requested by the NASA LaRC Executive Safety Council to review the rationale for a proposed change to the recertification requirements, specifically the internal inspection requirements, of the 8-Foot HTT LOX Run Tank and LOX Storage Tank. The Run Tank is an 8,000 gallon cryogenic tank used to provide LOX to the tunnel during operations, and is pressured during the tunnel run to 2,250 pounds per square inch gage (psig). The Storage Tank is a 25,000 gallon cryogenic tank used to store LOX at slightly above atmospheric pressure as a external shell, with space between the shells maintained under vacuum conditions.

Gilbert, Michael↗

The Mothball, Sustainment, and Proposed Reactivation of the Hypersonic Tunnel Facility (HTF) at NASA Glenn Research Center Plum Brook Station

The Hypersonic Tunnel Facility (HTF) located at the NASA Glenn Research Center s Plum Brook Station in Sandusky, Ohio, is the nation s only large-scale, non-vitiated, hypersonic propulsion test facility. The HTF, with its 4-story graphite induction heater, is capable of duplicating Mach 5, 6, and 7 flight conditions. This unique propulsion system test facility has experienced several standby and reactivation cycles. The intent of the paper is to overview the HTF capabilities to the propulsion community, present the current status of HTF, and share the lessons learned from putting a large-scale facility into mothball status for a later restart

Thomas, Scott R.↗

Increased Mach Number Capability for the NASA Glenn 10x10 Supersonic Wind Tunnel

Computational simulations and wind tunnel testing were conducted to explore the operation of the Abe Silverstein Supersonic Wind Tunnel at the NASA Glenn Research Center at test section Mach numbers above the current limit of Mach 3.5. An increased Mach number would enhance the capability for testing of supersonic and hypersonic propulsion systems. The focus of the explorations was on understanding the flow within the second throat of the tunnel, which is downstream of the test section and is where the supersonic flow decelerates to subsonic flow. Methods of computational fluid dynamics (CFD) were applied to provide details of the shock boundary layer structure and to estimate losses in total pressure. The CFD simulations indicated that the tunnel could be operated up to Mach 4.0 if the minimum width of the second throat was made smaller than that used for previous operation of the tunnel. Wind tunnel testing was able to confirm such operation of the tunnel at Mach 3.6 and 3.7 before a hydraulic failure caused a stop to the testing. CFD simulations performed after the wind tunnel testing showed good agreement with test data consisting of static pressures along the ceiling of the second throat. The CFD analyses showed increased shockwave boundary layer interactions, which was also observed as increased unsteadiness of dynamic pressures collected in the wind tunnel testing.

Wind tunnel↗

Increased Mach Number Capability for the NASA Glenn 10x10 Supersonic Wind Tunnel

Computational simulations and wind tunnel testing were conducted to explore the operation of the Abe Silverstein Supersonic Wind Tunnel at the NASA Glenn Research Center at test section Mach numbers above the current limit of Mach 3.5. An increased Mach number would enhance the capability for testing of supersonic and hypersonic propulsion systems. The focus of the explorations was on understanding the flow within the second throat of the tunnel, which is downstream of the test section and is where the supersonic flow decelerates to subsonic flow. Methods of computational fluid dynamics (CFD) were applied to provide details of the shock boundary layer structure and to estimate losses in total pressure. The CFD simulations indicated that the tunnel could be operated up to Mach 4.0 if the minimum width of the second throat was made smaller than that used for previous operation of the tunnel. Wind tunnel testing was able to confirm such operation of the tunnel at Mach 3.6 and 3.7 before a hydraulic failure caused a stop to the testing. CFD simulations performed after the wind tunnel testing showed good agreement with test data consisting of static pressures along the ceiling of the second throat. The CFD analyses showed increased shockwave boundary layer interactions, which was also observed as increased unsteadiness of dynamic pressures collected in the wind tunnel testing.

Diffuser↗

Enabling Small-Batch Custom Alloy Feedstock Development for Additive Manufacturing

Propulsion, hypersonic, and space nuclear power applications require high strength/high temperature components produced by AM but rely on expensive, supply-chain limited, non-AM optimized metals that lead to high buy-to-fly ratios. In addition, custom alloy development for AM is extremely expensive given the high-cost associated with feedstock development.​ Here, we highlight current efforts to develop a cost-effective process to enable application driven high-throughput AM-optimized metal alloy development using small powder batch processing. A cost-effective process for custom AM-feedstock development will enable fast industry infusion to aid future NASA missions and will enable commercial space partners and supply chain.

Fernando L Reyes Tirado↗

Seeing deep inside engines with X-rays

Argonne National Laboratory outside Chicago is creating a research program that will empower investigators to apply the sensing qualities of X-rays to the challenge of seeing what goes on inside scramjets, rotating detonation engines and other hypersonic propulsion concepts. The program’s architects describe the technology’s heritage and its time- and cost-saving benefits.

42 ENGINEERING↗

Dynamic interactions between hypersonic vehicle aerodynamics and propulsion system performance

Described here is the development of a flexible simulation model for scramjet hypersonic propulsion systems. The primary goal is determination of sensitivity of the thrust vector and other system parameters to angle of attack changes of the vehicle. Such information is crucial in design and analysis of control system performance for hypersonic vehicles. The code is also intended to be a key element in carrying out dynamic interaction studies involving the influence of vehicle vibrations on propulsion system/control system coupling and flight stability. Simple models are employed to represent the various processes comprising the propulsion system. A method of characteristics (MOC) approach is used to solve the forebody and external nozzle flow fields. This results in a very fast computational algorithm capable of carrying out the vast number of simulation computations needed in guidance, stability, and control studies. The three-dimensional fore- and aft body (nozzle) geometry is characterized by the centerline profiles as represented by a series of coordinate points and body cross-section curvature. The engine module geometry is represented by an adjustable vertical grid to accommodate variations of the field parameters throughout the inlet and combustor. The scramjet inlet is modeled as a two-dimensional supersonic flow containing adjustable sidewall wedges and multiple fuel injection struts. The inlet geometry including the sidewall wedge angles, the number of injection struts, their sweepback relative to the vehicle reference line, and strut cross-section are user selectable. Combustion is currently represented by a Rayleigh line calculation including corrections for variable gas properties; improved models are being developed for this important element of the propulsion flow field. The program generates (1) variation of thrust magnitude and direction with angle of attack, (2) pitching moment and line of action of the thrust vector, (3) pressure and temperature distributions throughout the system, and (4) performance parameters such as thrust coefficient, specific impulse, mass flow rates, and equivalence ratio. Preliminary results are in good agreement with available performance data for systems resembling the NASP vehicle configuration.

Flandro, G. A.↗

Engineering method for aero-propulsive characteristics at hypersonic Mach numbers

An engineering method has been developed for the rapid analysis of external aerodynamics and propulsive performance characteristics of airbreathing vehicles at hypersonic Mach numbers. This method, based on the theory of characteristics, has been developed to analyze fuselage-wing body combinations and body flaps with blunt or sharp leading/trailing edges. Arbitrary ratio of specific heat for the flowing medium can be specified in the program. Furthermore, the capability exists in the code to compute the inviscid inlet mass capture and momentum flux. The method is under development for computations of pressure distribution, and flow characteristics in the inlet, along with the effect of viscosity. Correlative studies have been performed for representative hypersonic configurations using the current method. The results of these correlations for various aerodynamics parameters are encouraging.

Goradia, Suresh↗

Laser-driven hypersonic air-breathing propulsion simulator

A feasibility study is presented of simulating airbreathing propulsion on small scale hypersonic models using laser energy. The laser heat addition scheme allows simultaneous inlet and exhaust flows during wind tunnel testing of models with scramjet models. The proposed propulsion simulation concept has extended the Kantrowitz (1974) idea to propulsive wind tunnel models of hypersonic aircraft. Critical issues in aeropropulsive testing of models based on a ramjet power plant are addressed which include transfer of the correct amount of energy to the flowing gas, efficient absorption of laser energy into the gas, and test performance under tunnel reservoir conditions and at reasonable Reynolds numbers.

Joshi, Prakash B.↗

Robust control of hypersonic vehicles considering propulsive and aeroelastic effects

The influence of propulsion system variations and elastic fuselage behavior on the flight control system of an airbreathing hypersonic vehicle is investigated. Thrust vector magnitude and direction changes due to angle of attack variations affect the pitching moment. Low structural vibration frequencies may occur close to the rigid body modes influencing the angle of attack and lead to possible cross coupling. These effects are modeled as uncertainties in the context of a robust control study of a hypersonic vehicle model accelerating through Mach 8 using H-infinity and mu synthesis techniques. Various levels of uncertainty are introduced into the system. Both individual and simultaneous appearance of uncertainty are considered. The results indicate that the chosen design technique is suitable for this kind of problem provided that a fairly good knowledge of the effects mentioned above is available. The order of the designed controller is reduced but robust performance is lost which shows the need for fixed order design techniques.

Buschek, Harald↗

Hypersonic cruise aircraft propulsion integration study, volume 2

Conceptual vehicle configuration and propulsion approach for a Mach 6 transport aircraft capable of carring 200 passengers 9260 km was investigated. Wind tunnel test data for various hypersonic transport configurations were examined. Canidates for baseline reference vehicles were selected. An explanation of technical methods which were used and configuration details which were significant in the final vehicle concept are given.

Morris, R. E.↗

Airframe-integrated propulsion system for hypersonic cruise vehicles

Research on a new, hydrogen burning, airbreathing engine concept which offers good potential for efficient hypersonic cruise vehicles is considered. Features of the engine which lead to good performance include; extensive engine-airframe integration, fixed geometry, low cooling, and the control of heat release in the supersonic combustor by mixed-modes of fuel injection from the combustor entrance. The engine concept is described along with results from inlet tests, direct-connect combustor tests, and tests of two subscale boiler-plate research engines presently underway at conditions which simulate flight at Mach 4 and 7.

Jones, R. A.↗

Airframe-integrated propulsion system for hypersonic cruise vehicles

The paper describes a new hydrogen-burning airframe-integrated scramjet concept which offers good potential for efficient hypersonic cruise vehicles. The characteristics of the engine which assure good performance are extensive engine-airframe integration, fixed geometry, low cooling, and control of heat release in the supersonic combustor by mixed modes of fuel injection from the combustor entrance. The present paper describes the concept and presents results from inlet tests, direct-connect combustor tests, and tests of two subscale boiler-plate research engines currently underway under conditions which simulate flight at Mach 4 and 7. It is concluded that this engine concept has the potential for high thrust and efficiency, low drag and weight, low cooling requirement, and application to a wide range of vehicle sizes.

Jones, R. A.↗

Survey of Aerothermodynamics Facilities Useful for the Design of Hypersonic Vehicles Using Air-Breathing Propulsion

This paper surveys the use of aerothermodynamic facilities which have been useful in the study of external flows and propulsion aspects of hypersonic, air-breathing vehicles. While the paper is not a survey of all facilities, it covers the utility of shock tunnels and conventional hypersonic blow-down facilities which have been used for hypersonic air-breather studies. The problems confronting researchers in the field of aerothermodynamics are outlined. Results from the T5 GALCIT tunnel for the shock-on lip problem are outlined. Experiments on combustors and short expansion nozzles using the semi-free jet method have been conducted in large shock tunnels. An example which employed the NASA Ames 16-Inch shock tunnel is outlined, and the philosophy of the test technique is described. Conventional blow-down hypersonic wind tunnels are quite useful in hypersonic air-breathing studies. Results from an expansion ramp experiment, simulating the nozzle on a hypersonic air-breather from the NASA Ames 3.5 Foot Hypersonic wind tunnel are summarized. Similar work on expansion nozzles conducted in the NASA Langley hypersonic wind tunnel complex is cited. Free-jet air-frame propulsion integration and configuration stability experiments conducted at Langley in the hypersonic wind tunnel complex on a small generic model are also summarized.

Arnold, James O.↗