Propulsion-Airframe Integration Test Techniques for Hypersonic Airbreathing Configurations at Langley Research Center (invited)

Witte, David W.; Huebner, Lawrence D.; Trexler, Carl A.; Cabell, Karen F.; Andrews, E. H.

doi:10.2514/6.2003-4406

Cited by 9 publications

(3 citation statements)

References 5 publications

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“…Several future reusable combined-cycle flight demonstrator concepts were studied to demonstrate combined turbomachinery and dual-mode scramjet propulsion in an integrated vehicle system. Work also proceeded on issues related to transonic drag, as hypersonic airbreathers can have particular difficulties accelerating through Mach 1 7 .…”

Section: B Flight Test Experiencementioning

confidence: 99%

Aerodynamics for Optimal Engine-Integrated Airbreathing Launcher Configurations

Lewis

Boyd

Cockrell

2004

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit

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An overview of some of the activities in hypersonic airbreathing aerodynamics and propulsion airframe integration is presented for the Space Vehicle Technology Institute. The Institute is a multi-university joint NASA-DoD program that was created as a center for research and education in future launch vehicle technologies. Perhaps more than any other type of flight vehicle, next generation space launchers will have to be analyzed as completely integrated aerodynamic-propulsion systems. Optimal aerodynamics will be vital to the development of efficient, engine-integrated launch vehicle forms, especially using airbreathing propulsion. To this end, inverse design approaches, design tradeoffs, and an understanding of relevant basic flow physics are all part of the Space Vehicle Technology Institute program. The relevance of these efforts to NASA activities is also described. I. IntroductionMONG the challenges in launch vehicle design is balancing the integrated requirements for practical propulsion with good volumeterics, structural efficiency, controllability, and heating survivability. For airbreathing vehicles, or those with extended reentry footprints, coupled aerodynamic performance is also vital. The degree of coupling and close integration raises many questions about practical aerodynamic designs for hypersonic flight.Of all future launch concepts, hypersonic airbreathers will have their own special propulsion-airframe integration challenges. For cruisers, it is well-known that the optimal propulsion system is one that maximizes the range by providing the highest product of specific impulse and lift-over-drag, L/D for a given fuel weight fraction. Airbreathers that consume large fractions of their weight are not strictly governed by the Breguet range equation, but the general trends of that simple formulation are still valid. 1 This will generally favor designs in which the engine contributes to lift, and where inlet efficiency is absolutely critical. 2 Lift-over-drag is as important as specific impulse for the performance of such vehicles. 3 Though accelerators are different than atmospheric cruisers, there are some analogies to be drawn.Accelerators, including airbreathing access-to-space vehicles, achieve maximum overall performance with greatest effective specific impulse, realized with the maximum difference between thrust and drag. This translates into the need to design efficient engine systems on low-drag airframes. Note that horizontal launchers, including airbreathing accelerators, will match lift to weight, and so must also have high L/D in horizontal flight.This need for high lift on horizontal vehicles stands in stark contrast to the requirements for vertical launch, especially with traditional rockets. In that case, drag represents a very small fraction of overall energy loss in flight to orbital speed, 7790 m/sec; the space shuttle velocity loss to gravity (1220 m/s) is over ten times greater than loses due to drag (118 m/s). In contrast, a horizontal launcher would have negligible gravity losse...

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Section: B Flight Test Experiencementioning

confidence: 99%

Aerodynamics for Optimal Engine-Integrated Airbreathing Launcher Configurations

Lewis

Boyd

Cockrell

2004

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit

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“…Various ground test techniques are used to evaluate the effects of powered operation on tip-to-tail flowpath and vehicle performance, including forebody-inlet test models, partial and full flowpath models with combustion, and the use of air or gas mixtures to simulate powered exhaust plume effects in aerodynamic facilities. 30 During the National Aero-Space Plane (NASP) program, significant work was done to investigate the use of cold-gas mixtures to simulate powered scramjet exhaust products in ground test facilities. [31][32][33] This technique was investigated in the supersonic and hypersonic speed regimes (Mach 4-10) with powered metric aftbody models to develop the technique and measure external nozzle pressures, exhaust plume impingement on wing surfaces and aftbody forces and moments.…”

Section: Aero-propulsive Interactionsmentioning

confidence: 99%

Aerosciences, Aero-Propulsion and Flight Mechanics Technology Development for NASA's Next Generation Launch Technology Program

Cockrell

2003

12th AIAA International Space Planes and Hypersonic Systems and Technologies

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The Next Generation Launch Technology (NGLT) program, Vehicle Systems Research and Technology (VSR&T) project is pursuing technology advancements in aerothermodynamics, aeropropulsion and flight mechanics to enable development of future reusable launch vehicle (RLV) systems. The current design trade space includes rocket-propelled, hypersonic airbreathing and hybrid systems in two-stage and single-stage configurations. Aerothermodynamics technologies include experimental and computational databases to evaluate stage separation of two-stage vehicles as well as computational and trajectory simulation tools for this problem. Additionally, advancements in high-fidelity computational tools and measurement techniques are being pursued along with the study of flow physics phenomena, such as boundary-layer transition. Aero-propulsion technology development includes scramjet flowpath development and integration, with a current emphasis on hypervelocity (Mach 10 and above) operation, as well as the study of aero-propulsive interactions and the impact on overall vehicle performance. Flight mechanics technology development is focused on advanced guidance, navigation and control (GN&C) algorithms and adaptive flight control systems for both rocketpropelled and airbreathing vehicles.

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“…Whilst a highly integrated vehicle was developed for nasa's x-43 flight experiment, little experimental data is available for this vehicle. As an example, Witte et al (2003) discusses airframe integration issues and test methodologies but does not present details of the experimental results and conclusions.…”

Section: Thesis Motivationmentioning

confidence: 99%

An experimental investigation of an airframe integrated three-dimensional scramjet engine at a Mach 10 flight condition

Doherty¹

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The University of Queensland in 2014 school of mechanical and mining engineering centre for hypersonics abstract Realisation of the dream of airbreathing access-to-space requires the development of a scramjet engine that produces sufficient net thrust to enable acceleration over a wide Mach number range. With engines that are highly integrated with the airframe, the net performance of a scramjet powered vehicle is closely coupled with the vehicle attitude and is difficult to determine only from component level studies. This work investigates the influence of airframe integration on the performance of an airframe integrated scramjet through the measurement of internal pressure distribution and the direct measurement of the net lift, thrust and pitching moment using a three-component stress wave force balance. The engine chosen as the basis for this study was the Mach 12 rectangularto-elliptical shape-transition (m12rest) scramjet that was developed by Suraweera and Smart (2009) as a research engine for access-to-space applications. The inlet and combustor flowpath were integrated with a slender 6°wedge forebody, streamlined external geometry and three dimensional thrust nozzle. The scale of the engine was chosen so that the entire engine would fit within the core-flow diamond (bi-conic) produced by a Mach 10 facility nozzle. The Mach 10b facility nozzle was chosen because it is the largest nozzle current in use with the t4 Stalker Tube and because the offdesign performance of a scramjet engine is of interest for access-to-space vehicles that must accelerate over a range of Mach numbers.Freejet experiments were conducted within the t4 Stalker Tube. Two trueflight Mach 10 test conditions were used: a high pressure test condition that replicated flight at a dynamic pressure of 48 kPa and a low pressure test condition that replicated flight at a dynamic pressure of 28 kPa. Scaling of the test conditions according to the established binary scaling law was not completed due to facility operational limits.The engine featured two fuel injection stations from which gaseous hydrogen was injected. The first injection station was partway along the length of the inlet while the second injection station was at the start of the combustor behind a rearward facing circumferential step. In addition to investigating inlet-only and step-only injection, a combined scheme where 68 % of the fuel was injected from the step station and 32 % from the inlet station was also investigated.To support the analysis of the experimental results, numerical simulations of the engine with no fuel injection were conducted using the nasa code vulcan. Analysis of the simulations show that the mass capture ratio with respect to the projected inlet area is approximately 60 % at each test condition. The simulations also show that spillage of flow from the slender forebody accounts for just 12 % of the flow through the projected iii inlet area, a small but non-negligible fraction. By integrating the engine surface forces, the drag coefficient with respect ...

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Propulsion-Airframe Integration Test Techniques for Hypersonic Airbreathing Configurations at Langley Research Center (invited)

Cited by 9 publications

References 5 publications

Aerodynamics for Optimal Engine-Integrated Airbreathing Launcher Configurations

Aerodynamics for Optimal Engine-Integrated Airbreathing Launcher Configurations

Aerosciences, Aero-Propulsion and Flight Mechanics Technology Development for NASA's Next Generation Launch Technology Program

An experimental investigation of an airframe integrated three-dimensional scramjet engine at a Mach 10 flight condition

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