Comparison of Mach 10 Scramjet Measurements from Different Impulse Facilities

McGilvray, Matthew; Kirchhartz, Rainer; Jazra, Thomas

doi:10.2514/1.j050025

Cited by 16 publications

(6 citation statements)

References 8 publications

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“…Sub-designscale testing is standard practice in the field of hypersonics due to size constraints imposed by the available wind tunnel facilities. Typically, to achieve similitude of the flow field between a sub-scale wind tunnel experiment and full-scale flight article, some form of scaling of the flow condition is required (Bushnell, 2006;McGilvray et al, 2010). The predominant scaling method used for supersonic combustion experiments is the binary scaling method (Hornung, 1988;Stalker and Pulsonetti, 2004) for which the flow velocity, temperature and gas composition of the test condition are matched to flight while the density is adjusted such that the product of density and length remains constant.…”

Section: Influence Of Flight Dynamic Pressurementioning

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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Section: Influence Of Flight Dynamic Pressurementioning

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 former was used by McGilvray [74] for the first test of a nose-to-tail scramjet engine in an expansion tube. For this study a Mach 10.1, 165 kPa dynamic pressure condition was developed for a test time of 550 µs and a total enthalpy of 5.3 MJ kg −1 [142]. The authors tested a 2 5 scaled 2D hydrogen-fuelled scramjet derived from an existing scramjet tested in T4 [142], the large-scale RST facility operated by the University.…”

Section: Scramjet Testing In Expansion Tubesmentioning

confidence: 99%

“…For this study a Mach 10.1, 165 kPa dynamic pressure condition was developed for a test time of 550 µs and a total enthalpy of 5.3 MJ kg −1 [142]. The authors tested a 2 5 scaled 2D hydrogen-fuelled scramjet derived from an existing scramjet tested in T4 [142], the large-scale RST facility operated by the University. The study compared the results obtained from the two facilities, and showed good agreement in comparison to the experimental uncertainties [142].…”

Section: Scramjet Testing In Expansion Tubesmentioning

confidence: 99%

“…The authors tested a 2 5 scaled 2D hydrogen-fuelled scramjet derived from an existing scramjet tested in T4 [142], the large-scale RST facility operated by the University. The study compared the results obtained from the two facilities, and showed good agreement in comparison to the experimental uncertainties [142]. This was considered a validation of X2, and expansion tubes in general, for scramjet testing.…”

Section: Scramjet Testing In Expansion Tubesmentioning

confidence: 99%

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Free-jet testing of a Mach 12 scramjet in an expansion tube

Toniato¹

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Scramjet technology has the theoretical potential to provide air-breathing propulsion as a more efficient alternative to conventional rocket propulsion. Since the vehicle captures its oxidiser from the atmosphere -as opposed to carrying it like a rocket -the specific impulse can theoretically be increased by an order of magnitude, thereby increasing payload mass fractions. In this context, threestage hybrid rocket-scramjet-rocket launch systems have shown to potentially provide a cost-effective and flexible solution for satisfying the requirements of the small-satellites market. However, to be economically feasible, the proposed scramjet-powered second stage would be reusable.Rectangular-to-Elliptical-Shape-Transitioning (REST) engines have shown to be a viable concept that can be integrated into access-to-space vehicles operating between Mach 5 and 12. The half-scale Mach 12 REST engine is a research scramjet specifically designed to operate in the last part of the ascent trajectory. Previous studies have demonstrated the ability of this design to successfully operate at equivalent flight conditions of Mach 11.6, 30 kPa dynamic pressure. However, tests have never been performed in freejet mode at the design conditions, as the facility which was used -the T4 reflected shock tunnel -was limited, like all RSTs by the extreme total pressure requirements of a Mach 12 flight. These limitations are aggravated by the even higher pressure necessary for pressure-length scaling, used to conserve the flow similarity between the half-scale experimental model and the flight engine.To overcome these limitations and allow freejet testing with pressure-length scaling, the use of expansion tubes has been proposed. These are currently the only kind of facility capable of producing these high-pressure requirements. Currently, the University of Queensland operates the X3 expansion tube, which is one of the few facilities worldwide with the potential to produce both the required total pressures and sufficiently long test times (up to 1.5 ms) to test an engine such as the Mach 12 REST engine.

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“…McGilvary et al (2010) [65] applied the PL scaling criteria in the testing of two scaled Mach 10 scramjet engines in the University of Queensland's T4 reflected shock tunnel and X2 expansion tube. Test section size restrictions and test time limitations of the X2 expansion tube required the test model to be a 40% length scale model of the engine tested in the T4 reflected shock tunnel.…”

Section: Scaling Studies Of Scramjetsmentioning

confidence: 99%

Geometric scaling studies of an inlet-fuelled axisymmetric radical farming scramjet engine

Oberg¹

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Scramjet engine technology has the potential to transform commercial flight and mankinds' ability to access space. Major technology hurdles remain which must be investigated and resolved before the potential of the scramjet engine can be realised. The ability to scale a small geometric scale scientific test model to a large practical vehicle size with similar performance characteristics is one such challenge. In this study, the small scale geometric scaling characteristics of a scramjet engine, one such tool to aid in future experimental based investigations and overall scramjet development, is presented. The study specifically concentrates on investigating the similarity effects for a new type of scramjet engine, the axisymmetric inlet-fuelled radical farming scramjet engine, and is concerned with the Pressure-Length scaling laws in both plain air mediums and hypersonic shock tunnel facility test mediums.

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Comparison of Mach 10 Scramjet Measurements from Different Impulse Facilities

Cited by 16 publications

References 8 publications

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

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

Free-jet testing of a Mach 12 scramjet in an expansion tube

Geometric scaling studies of an inlet-fuelled axisymmetric radical farming scramjet engine

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