Free-piston driver optimisation for simulation of high Mach number scramjet flow conditions

Gildfind, David; Morgan, Richard G.; McGilvray, Matthew; Jacobs, Peter A.; Stalker, R. J.; Eichmann, Troy N.

doi:10.1007/s00193-011-0336-9

Cited by 46 publications

(22 citation statements)

References 20 publications

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“…These major wave processes are depicted in Figure 3.2 in the form of an x-t diagram. Further discussion and analysis of free-piston driven reflected shock tunnels and expansion tunnels may be found in the work of Stalker (1966Stalker ( , 1967Stalker ( , 1989Stalker ( , 2006a and Gildfind et al (2011).…”

Section: Test Facilitymentioning

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: Test Facilitymentioning

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 tube consists of a reservoir which accelerates the piston through the compression tube rupturing the primary diaphragm, and driving the test gas through the acceleration tube into the test section. (Gildfind et al, 2011) …”

Section: The X2 Expansion Tubementioning

confidence: 99%

Thermal imaging of ducted hypersonic flows

Fredatovich¹

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The development of scramjet technology has presented the need for methods to analyse the temperature of the hypersonic flow experienced internally by the scramjet. A new technique has been proposed that incorporates an infrared window in the wall of a duct, a thin black film is placed between the flow and the window. This allows an infrared sensor to measure the surface temperature by reading the radiation emitted from the underside of the film, through the window.A semi-infinite analysis was performed on the thin film, assuming the material was either a graphite coating, or a Krylon™ matte black paint coating. It was found that the graphite film would have to be below 14μm, and the Krylon™ film below 4.5μm for the temperature on the underside of the film to experience a third of the change seen by the surface. Magnesium fluoride was chosen for the IR window due to its transmissivity and material properties. Bench tests were performed by applying heat to one side of the film, and measuring the cooling of either side with IR sensors. This showed a trend for temperature decrease but with a temperature difference of 35°C with the Krylon™ film. The graphite film showed similar trends with a larger temperature difference between surfaces, which is thought to be due to the calibration process only being performed on the paint.An experiment was carried out in the X2 expansion tube using both the painted film and graphite film, and two flow conditions; a Venus atmospheric entry condition and an air condition. Analysis with Schultz and Jones' (1973) exact thin film theory showed an increase in temperature was expected for the graphite film underside, but was unlikely with the painted film. The painted film showed an oscillating response followed by a 40°C, and 20°C temperature change in the Venus and air conditions, respectively. The graphite film shows a temperature change of 325°C and 150°C for the Venus and air conditions, respectively. It was concluded that the Krylon™ film is likely due to errors because of the trend, whilst the graphite film is too transmissive at its current thickness of 5-6μm.The new method of infrared thermography to measure ducted hypersonic flows remains invalidated, which was the main aim of this study. A greater understanding has been gained, and in future development it is recommended that a thicker graphite film is used, or other carbon materials researched, and that the calibration process is undertaken in the exact conditions of which the experiment will be performed.ii AcknowledgementsThe completion of this thesis has been a large undertaking and would not have been possible without the assistance and expertise of a number of people. I would like to acknowledge the following people:Prof Richard Morgan; His wealth of knowledge and experience often provided a simple solution to a complex task, and despite a large number of responsibilities he was always able to make time to discuss this thesis.All of the post-graduate students within the X-labs. Everyone has helped me in one way o...

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“…The X2 expansion tube is a free-piston driven, impulse test facility, capable of generating uniquely high enthalpies and total pressures. X2 consists of a compression tube, driven tube and test section [4]. The driven tube in X2 is capable of being divided into up to three separate sections, using Mylar diaphragms, allowing the facility to operate as a non-reflected shock tunnel, a simple expansion tunnel, or an expansion tunnel with secondary driver [4].…”

Section: Project Relevance and Contributionmentioning

confidence: 99%

“…X2 consists of a compression tube, driven tube and test section [4]. The driven tube in X2 is capable of being divided into up to three separate sections, using Mylar diaphragms, allowing the facility to operate as a non-reflected shock tunnel, a simple expansion tunnel, or an expansion tunnel with secondary driver [4]. For the purposes of this thesis, X2 was configured as a simple expansion tunnel.…”

Section: Project Relevance and Contributionmentioning

confidence: 99%

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Expansion tunnel heat transfer measurements of the ESA-IXV re-entry vehicle

Vella¹

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In February 2015, the European Space Agency successfully launched the first flight of their blunt nosed, lifting body re-entry craft, called the Intermediate eXperimental Vehicle (IXV). During re-entry, significant aerodynamic heating was experienced. This thesis aimed to simulate the peak heating re-entry conditions on a scale model of the IXV within UQ's X2 expansion tunnel, with the overall goal of comparing measured heat transfer to existing CFD data.A simplified, 1/52 scale model of the IXV for a 45• angle of attack, and subsequent mounting hardware, was successfully designed and machined. A total flow enthalpy of H t = 25.285M J/kg, and binary scaled equilibrium post shock flow density of ρ 10,e = 0.02434kg/m 3 was achieved using a 90% Helium X2 fill condition, which represented the scaled peak heating re-entry conditions for Mach 24.67 at 75.42 km altitude.Seven experiment shots were performed for the scale model at this condition, with the temperature recorded at six independent model locations using a new design of type-E thermocouple. The thermocouple design proved to be robust, reliable and resilient. Im-

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Free-piston driver optimisation for simulation of high Mach number scramjet flow conditions

Cited by 46 publications

References 20 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

Thermal imaging of ducted hypersonic flows

Expansion tunnel heat transfer measurements of the ESA-IXV re-entry vehicle

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