Drags in Scramjet Engine Testing: Experimental and Computational Fluid Dynamics Studies

Mitani, Tohru; Kanda, Takeshi; Hiraiwa, Tetsuo; Igarashi, Yasutaka; Nakahashi, Kazuhiro

doi:10.2514/2.5466

Cited by 28 publications

(8 citation statements)

References 11 publications

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“…Despite this justification for focussing on the internal performance of an engine, jaxa researchers have also reported, albeit briefly, on the external and installation drag of the engine. Consequently a number of interesting results have been obtained including, (1) agreement to within 5 % for the drag obtained from the force balance and that obtained from integration of the measured pressure distribution and estimated skin friction distribution (see Figure 2.11 and Mitani et al, 2002Mitani et al, , 1999; (2) experimental demonstration that the external drag and total fuel-off internal drag are comparable (Mitani et al, 1999), and (3) demonstration that the internal viscous drag accounts for significantly more than 50 % of the total internal drag (Mitani et al, 2002).…”

Section: Japan Aerospace Exploration Agencymentioning

confidence: 98%

“…Similarity of the inlet and combustor viscous drag components for the case of no fuel injection is not a new result. Turner (2010, Table 3.7) found that inlet viscous drag was approximately 34 % larger than combustor viscous drag for a rest scramjet engine designed for flight at Mach 8; Paull et al (1995a) and Tanimizu et al (2009) found that viscous drag on the inlet and cowl of a quasi-axisymmetric scramjet engine was comparable with combustor viscous drag for a Mach number range of 6 to 10, and Mitani et al (1999) showed that inlet viscous drag was approximately 2.3 times larger than combustor viscous drag for a two-dimensional side-wall compression scramjet engine at Mach 4. The large variation of the results from literature indicates that the inlet-to-combustor viscous drag ratio is strongly dependent on the engine design.…”

Section: Engine Surface Forcesmentioning

confidence: 99%

“…Injection of fuel within the isolator of the m12rest engine is currently under investigation (Barth et al, 2012, Section III.C), albeit with the goal of more effectively delivering fuel into the mainstream flow of the engine. Based on the data presented in Figure 5.11a, the results of Mitani et al (1999), Tanimizu et al (2009), andTurner (2010) and the preceding discussion, it is recommended here that some research effort be focussed on reducing inlet viscous drag, with particular emphasis on the suitability and performance of multiporthole injector arrays, similar to that studied by Pudsey et al (2013).…”

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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: Japan Aerospace Exploration Agencymentioning

confidence: 98%

Section: Engine Surface Forcesmentioning

confidence: 99%

mentioning

confidence: 99%

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

Doherty¹

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“…All these advantages of the intrusive strut may far overweigh the drawbacks such as total pressure losses, drag and local cooling requirements. However, most of the strut-based experimental and numerical studies 12–19 reported in the literatures concerned the above flow phenomena take hydrogen as the fuel. The studies on strut-based scramjet combustors with kerosene fuel are highly limited.…”

Section: Introductionmentioning

confidence: 99%

Combustion characteristic using O₂-pilot strut in a liquid-kerosene-fueled strut-based dual-mode scramjet

Bao

Zong

et al. 2012

Proceedings of the Institution of Mechanical Engineers, Part G:

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A set of exploratory experiments are conducted to test a newly designed strut for fuel injection and flame holding in a liquid-kerosene-fueled dual-mode scramjet combustor. The thickness of the strut is 8 mm and the front blockage is about 8%. To organize stable combustion in a Mach number equal to 2.6 air flow under this thin strut using room-temperature liquid kerosene in a flash wall combustor without any cavity and other flame holders, some oxygen is injected through a set of orifices at the back of the strut, based on which a stable center local flame is generated at the back of the strut and the main flow combustion can be organized around this local flame. Experimental results show that stable combustion can be achieved at the center of the combustor with a wide range of equivalence ratio from 0.19 to 1 based on this center flame strut strategy. Through the analysis of the pressure distribution along the combustor, different combustor modes appear with different equivalence ratio. The article also gives some discussions about different influence of the oxygen to the combustion process under different equivalence ratio.

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“…Mitani et al 8 measured thrust, lift, and pitching moment on a sidecompression engine at Mach 4 to 8 flight conditions in a vitiatedair facility at National Aerospace Laboratory (NAL). The model was suspended from a support strut with a diamond cross section on the axial-force measuring system.…”

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Scramjet Lift, Thrust and Pitching-Moment Characteristics Measured in a Shock Tunnel

Robinson

Mee

Paull

2006

Journal of Propulsion and Power

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Lift, pitching moment, and thrust/drag on a supersonic combustion ramjet were measured in the T4 free-piston shock tunnel using a three-component stress-wave force balance. The scramjet model was 0.567 m long and weighed approximately 6 kg. Combustion occurred at a nozzle-supply enthalpy of 3.3 MJ/kg and nozzle-supply pressure of 32 MPa at Mach 6.6 for equivalence ratios up to 1.4. The force coefficients varied approximately linearly with equivalence ratio. The location of the center of pressure changed by 10% of the chord of the model over the range of equivalence ratios tested. Lift and pitching-moment coefficients remained constant when the nozzle-supply enthalpy was increased to 4.9 MJ/kg at an equivalence ratio of 0.8, but the thrust coefficient decreased rapidly. When the nozzle-supply pressure was reduced at a nozzle-supply enthalpy of 3.3 MJ/kg and an equivalence ratio of 0.8, the combustion-generated increment of lift and thrust was maintained at 26 MPa, but disappeared at 16 MPa. Measured lift and thrust forces agreed well with calculations made using a simplified force prediction model, but the measured pitching moment substantially exceeded predictions. Choking occurred at nozzle-supply enthalpies of less than 3.0 MJ/kg with an equivalence ratio of 0.8. The tests failed to yield a positive thrust because of the skin-friction drag that accounted for up to 50% of the fuel-off drag. Nomenclatureresponse function or matrix H = enthalpy L = lift force l = chord length (=0.567 m) M = Mach number m = pitching moment P = pressure S = reference area (=3.192 × 10 −3 m 2 ) T = temperature t = time u, u = input function or vector v = velocity y, y = output function or vector γ = ratio of specific heats = strain vector ρ = density = equivalence ratio Subscripts A = axial direction a, b, c, d = stress bar A, B, C or D M = moment direction N = normal direction o = about leading edge of model

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Drags in Scramjet Engine Testing: Experimental and Computational Fluid Dynamics Studies

Cited by 28 publications

References 11 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

Combustion characteristic using O₂-pilot strut in a liquid-kerosene-fueled strut-based dual-mode scramjet

Scramjet Lift, Thrust and Pitching-Moment Characteristics Measured in a Shock Tunnel

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Drags in Scramjet Engine Testing: Experimental and Computational Fluid Dynamics Studies

Cited by 28 publications

References 11 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

Combustion characteristic using O2-pilot strut in a liquid-kerosene-fueled strut-based dual-mode scramjet

Scramjet Lift, Thrust and Pitching-Moment Characteristics Measured in a Shock Tunnel

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Combustion characteristic using O₂-pilot strut in a liquid-kerosene-fueled strut-based dual-mode scramjet