Five times faster than the speed of sound
In aerodynamics, hypersonic speed greatly exceeds the speed of sound. On the ground, sound waves travel at around 340 metres per second. Any faster than this is supersonic, and five or more times faster is hypersonic. Unlike supersonic flow, with a hypersonic flow there is no sound barrier that is broken. As a vehicle moves faster and faster, the heat transfer of the flow starts to become important as the kinetic energy of the object converts to heat in the surrounding gases.Ìý
In the natural world, objects such as meteors and asteroids move through the Earth’s atmosphere hypersonically. Space shuttles and other space vehicles that we send to other planets, like the Mars Pathfinder-type probes, are man-made hypersonic vehicles. There have also been attempts to build aircraft that fly at hypersonic speeds here on Earth.
Associated schools, institutes & centres
Impact
Hypersonic and high-speed flow research at ¶¶Òõ¶ÌÊÓƵ investigates the gas dynamics of chemically reacting and real-gas flows. These inform the design of the hypersonic propulsion systems and planetary entry systems required to achieve practical hypersonic flight for high-speed aircraft. This is achieved by solving fundamental problems in aerothermodynamics, including the effects of chemical reactions and real-gas effects on laminar and turbulent flows of gas mixtures.Ìý
These processes include separated flows, leading-edge bluntness effects, surface temperature effects, wake flows, and fluid-thermal-structural interactions. We investigate these processes using a combination of experimental, mathematical analysis, and numerical simulation. ÌýÌý
We have several significant research achievements, including:Ìý
- The first demonstration of laser ignition as a means of enhancing the supersonic combustion of hydrogen.Ìý
- The world’s fastest scanning absorption-based temperature measurements, capable of 1.6 million spectra (and hence temperature measurements) per second.Ìý
- Developing instrumented free-flight models for developing hypersonic control parameter databases for generic flight configurations.Ìý
- Developing resonantly enhanced shearing interferometry (RESI), a flow visualisation technique for low-density flows that increases sensitivity to density gradients by more than 100 times.Ìý
- First measurements of 2D two-component velocity distributions in hypersonic separated flows using a non-intrusive technique, resulting in advances in analytical modelling of these flows.Ìý
- Developing new non-intrusive technologies for measuring fundamental quantities such as diffusion coefficient and viscosity at rarefied conditions, where such measurements have previously proved too difficult to perform.Ìý
- We host a database of our own high-speed FSI unit cases and those of the international community.Ìý.
Competitive advantage
We invested several decades to understanding the application of advanced laser-based diagnostic techniques to hypersonic flow measurements.
- We have one of very few facilities in the world with a suite of several non-intrusive measurement and visualisation techniques with the ability to generate conditions simulating high-speed flight. This makes our facility among the best understood and best characterised hypersonic facilities in the world. ÌýÌý
- We also have other facilities including a supersonic wind tunnel for steady supersonic flows with Mach numbers 2 to 3, or a rectangular shock tube with a 150 mm x 75 mm cross-section, together with a suite of high-speed cameras (frame rates up to 10 million framers per second) combined with several different visualisation systems (schlieren, shadowgraph, shearing interferometry), which can be used individually or as combinations.Ìý
- We are capable of testing models with hot walls, to more realistically simulate real gas conditions of hypersonic entry and flight scenarios. ÌýÌý
- Our combination of hypersonic and diagnostic expertise makes us a leading research group in the area of supersonic ignition and combustion processes.Ìý
- We have long-standing expertise in the design, simulation, and measurement of the thermal-structural behaviour of high-speed vehicles and propulsion systems.Ìý
- We have developed unique capabilities for the dynamic testing of critical aspects of hypersonic flight including:
- fluid-thermal-structural interactionsÌý
- the use of tunnel-based free flight testing for the characterisation of the aerodynamic envelope of vehicle geometries and dynamic separations system in the loop testing of control approaches including fluidics.
Successful applications
¶¶Òõ¶ÌÊÓƵ Space’s applications of our SSA researchÌýinclude:Ìý
- using our optical and numerical SSA techniques to studyÌýthe reflected-sunlight light curves that are generated due to various motions of the Buccaneer Risk Mitigation Mission spacecraftÌý
- aero-assisted formation control strategies for the Royal Australian Air ForceÌýM2 dual satellite programÌýÌý
- applying our understanding of the physics of ionospheric aerodynamics to propose propulsion-free satellite de-orbit approaches from higher altitudes than normally thought possibleÌý
- multiple US Air Force Office of Scientific Research (AFOSR) grants for ionospheric aerodynamic research to enable improved orbital control of LEO spacecraftÌý
- imaging the deployment of the Plant Flock 3p (the largest number of satellites launched on a single rocket in history) just two hours after launchÌý
- obtaining light curve information onÌýPlant Flock 3pÌýcubesats,Ìýto assistÌýinternational universities withÌýunderstandingÌýand troubleshootingÌýthe behaviour of their satellitesÌý
- assisting CSIRO and JPL in the analysis of dataÌýbyÌýapplying the Tidbinbilla and Parkes very large radio telescopes as bi-static radar instruments for tracking near-Earth asteroids.
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Over the lifetime of the group, we have collaborated with many university and industry partners. Our research has received continued support from theÌý, theÌý and theÌýÌýover many years.Ìý
Our current collaboration partners on funded projects include:Ìý
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- Currao GMD, Neely AJ, Kennell CM, Gai SL, Buttsworth DR (2019)Ìý, AIAA Journal. 57(11), 4819-4834. DOI: 10.2514/1.J058375Ìý
Ìý - Hruschka R, O’Byrne S, Kleine H (2010)Ìý, Exp. Fluids, 48(6):1109-1120, DOI: 10.1007/s00348-009-0794-3Ìý
Ìý - Hruschka R, O’Byrne S, Kleine H (2008)Ìý. Appl. Optics, 47(24):4352-4360, DOI: 10.1364/AO.47.004352 Ìý
Ìý - Kaebe, BD, Robins NP, Boyson TK, Kleine H, O'Byrne S (2018)Ìý, Applied Optics 57, 5680; DOI: 10.1364/AO.57.005680 Ìý
Ìý - Kennell C, Neely A, Tahtali M, Buttsworth DR, Choudhury R (2016)Ìý, AIAA 2016-1088, DOI:10.2514/6.2016-1152Ìý
Ìý - Khraibut A, Gai SL, Neely AJ (2019)Ìý, J. Fluid Mech., 878:386-419, DOI: 10.1017/jfm.2019.614Ìý
Ìý - Kleine H (2017)Ìý, Springer, Heidelberg, pp. 127-155; DOI: 10.1007/978-3-319-61491-5_6Ìý
Ìý - Le Page LM, Barrett M, O’Byrne S, Gai SL (2020). Physics of Fluids 32, 036103, DOI: 10.1063/5.0004266Ìý
Ìý - McQuellin L, Kennell C, Sytsma J, Choudhury R, Neely AJ, Buttsworth D (2020)Ìý, AIAA-2020-2451, DOI: 10.2514/6.2020-2451Ìý
Ìý - McQuellin LP, Neely AJ, Currao GMD (2020)Ìý, AIAA-2020-2419, DOI: 10.2514/6.2020-2419Ìý
Ìý - Prakash, R, Le Page, LM, McQuellin, LP, Gai, SL, O’Byrne S (2019)ÌýJournal of Fluid Mechanics, 879, 633-681, DOI: 10.1017/jfm.2019.692Ìý
Ìý - Vennik J, Neely AJ, Tuttle T, Choudhury R, Buttsworth DR (2017)Ìý, AIAA-2017-2194. DOI: 10.2514/6.2017-2194Ìý
- Currao GMD, Neely AJ, Kennell CM, Gai SL, Buttsworth DR (2019)Ìý, AIAA Journal. 57(11), 4819-4834. DOI: 10.2514/1.J058375Ìý
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Hypersonic TurbulenceÌý- We are working in collaboration with the US Air Force Academy on making new high-speed measurement and theory of the transition from laminar to turbulent flow over simple shapes in hypersonic flow. This is one of the most challenging problems in classical aerospace engineering.
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We are actively involved in science and technology outreach including:Ìý
- the ¶¶Òõ¶ÌÊÓƵ Young Women in Engineering (YoWIE) programÌý
- the Royal Aeronautical Society Ìý
- the Cool Aeronautics program Ìý
- a variety of individual outreach activities in local schools.
Study with us
We offer courses in both hypersonic and gas-turbine engine theory at the undergraduate level, as well as a course in instrumentation.Ìý
For further informationÌýplease contactÌýÌýorÌý.
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