Development of a new force measurement method for scramjet testing in a high enthalpy shock tunnel

Takahashi, Masahiro; Ueda, Shuichi; Komuro, Tomoyuki; Sato, K.; Tanno, Hideyuki; Itoh, Katsuhiro

doi:10.2514/6.1999-4961

Cited by 11 publications

(7 citation statements)

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“…The generation of test flows at speeds above Mach 8 is limited to impulse facilities such as reflected-shock and shock-expansion tunnels. 6,7 Within such facilities, force blance testing is particularly difficult, though both stress-wave 8 and accelerometer based techniques 9 have matured to the level where multi-component force measurements on scramjet vehicles and blunt bodies are possible. 10,11 More recently, an optical tracking method has been developed 12,13 and successfully applied to both an entirely free-flying reentry capsule 14 as well as a fuelled scramjet engine.…”

Section: Introductionmentioning

confidence: 99%

“…This work represents the first time that force data have been measured for a hydrogen fuelled REST scramjet engine at true-flight Mach 10 test conditions. Nomenclature A area, m 2 A axial direction, m a axial coordinate, m A o output specification matrix A F projected frontal area, m 2 A p projected planar or planform area, m 2 a vi element of output specification relating strain output v to stress bar i output C D drag coefficient CF normalised centre of force location C L lift coefficient C M moment coefficient ∆h c heat of formation, J/kg ρ density, kg/m 3 d k j moment arm for calibration hit in direction k at calibration location j, m F force, N G global impulse response function G impulse response function g acceleration due to gravity, 9.81 m/s 2 G ij k individual impulse response function for stress bar i due to a force at calibration location j in direction k G vl sub-matrix of global impulse response function that relates output v to a distributed load in direction l H total enthalpy, J/kg or height, m h enthalpy, J/kg L …”

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confidence: 99%

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Measurement of Three-Components of Force on an Airframe Integrated Scramjet at Mach 10

Doherty¹,

Smart²,

Mee³

2015

20th AIAA International Space Planes and Hypersonic Systems and Technologies Conference

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Force balance experiments have been conducted within The University of Queensland's T4 Stalker Tunnel with a small airframe-integrated three-dimensional scramjet engine using a three-component stress wave force balance. The tests were conducted at conditions replicating flight at Mach 10 and a dynamic pressure of 52 kPa or 28 kPa. The internal flowpath featured a rectangular-to-elliptical shape transition (REST) inlet, an elliptical combustor with a constant area and a diverging section, and a three-dimensional thrust nozzle. This flowpath was integrated with a forebody and streamlined external geometry to provide the test model. Gaseous hydrogen fuel was injected either through portholes on the inlet, from a series of portholes behind the rearward facing step at the combustor entrance, or a combination of the two. The fuel-off drag coefficient was measured to be 0.246 ± 0.025 and 0.312 ± 0.032 at the high and low dynamic pressure test conditions respectively. At a fuel equivalence ratio of 1.20, the drag coefficient reduced to 0.118 ± 0.034 for a combined injection scheme at the high dynamic pressure test condition, corresponding to a specific impulse increment of 2160 s and a specific thrust increment of 740 N s/kg. This work represents the first time that force data have been measured for a hydrogen fuelled REST scramjet engine at true-flight Mach 10 test conditions. NomenclatureA area, m 2 A axial direction, m a axial coordinate, m A o output specification matrix A F projected frontal area, m 2 A p projected planar or planform area, m 2 a vi element of output specification relating strain output v to stress bar i outputheat of formation, J/kg ρ density, kg/m 3 d k j moment arm for calibration hit in direction k at calibration location j, m F force, N

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Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Measurement of Three-Components of Force on an Airframe Integrated Scramjet at Mach 10

Doherty¹,

Smart²,

Mee³

2015

20th AIAA International Space Planes and Hypersonic Systems and Technologies Conference

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“…3 This is despite the necessary tools existing (see Figure 2.9 -Hyper-X vfs and hxfe installation in the nasa larc 8-ft htt for e.g. Takahashi et al, 1999). The engine data recorded at the Mach 10 condition consisted of surface static pressure measurements, thin-film heat flux gauges and a Pitot pressure rake that was used to survey the forebody flow (Bakos et al, 1999).…”

Section: National Aeronautics and Space Administrationmentioning

confidence: 99%

“…As a part of its infastructure, jaxa have developed a free-flight accelerometer-based force balance (Takahashi et al, 1999;Tanno et al, 2005). Shown in Figure 2.12, this balance is a single-component force balance that has been used with engine models up to 3 m in length (Itoh, 2005).…”

Section: Japan Aerospace Exploration Agencymentioning

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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“…A practical and widely used solution is acceleration compensation [1,3,8,9,11,13,14]. That is, to embed some accelerometers into the balance in the hope that the vibration signal can be removed from the balance signal produced.…”

Section: Introductionmentioning

confidence: 99%

Wave system fitting: A new method for force measurements in shock tunnels with long test duration

Luo

Wang

Chun

et al. 2015

Mechanical Systems and Signal Processing

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a b s t r a c tForce measurements in shock tunnels are difficult due to the existence of vibrations excited by a sudden aerodynamic loading. Accelerometer inertia compensation could reduce its negative effect to some extent, but has inherent problems. A new signal decomposition method, wave system fitting (WSF), is proposed to remove vibration waves of low frequency. The WSF is accelerometer-free. It decomposes the balance signal and can separate vibration waves without the influence on the DC component, and it does work no matter the cycle of the sample signal is complete or not. As a standard signal postprocessing tool in JF-12, the application results show that it works reliably with high accuracy, and it can also explain puzzling signals encountered in JF-12. WSF method is especially useful and irreplaceable whenever only a few cycles of a periodic signal could be obtained, as is usual for shock tunnels.

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Development of a new force measurement method for scramjet testing in a high enthalpy shock tunnel

Cited by 11 publications

References 1 publication

Measurement of Three-Components of Force on an Airframe Integrated Scramjet at Mach 10

Measurement of Three-Components of Force on an Airframe Integrated Scramjet at Mach 10

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

Wave system fitting: A new method for force measurements in shock tunnels with long test duration

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