Cranz-Schardin visualisation of a hypersonic cone with gas injection

Buttsworth, David R. and Sercombe, David B. (2009) Cranz-Schardin visualisation of a hypersonic cone with gas injection. In: 28th International Congress on High-Speed Imaging and Photonics, 9-14 Nov 2008, Canberra, Australia.

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We have developed a five-picture Cranz-Schardin system for Schlieren flow visualization on a gun tunnel facility at the University of Southern Queensland to aid the study of unsteady shock systems in nominally steady hypersonic flows. The system produces useful images at framing rates up to about 1 MHz even though the system development was constrained by a very modest budget. The system uses multiple LED light sources driven by an in-house designed device that delivers a high current pulse to each LED with a programmable time delay between each pulse. The images are captured using four separate, black and white video devices and one digital still camera. The utility of the system is demonstrated by imaging gas injection from an annulus on a 10 degree half angle cone positioned at the exit of the contoured Mach 7 nozzle. Visualisation of the cone without gas injection demonstrates that the half angle of the conical shock is approximately 13.9 degrees (the Taylor-Maccoll conical shock angle at Mach 7 for an inviscid cone half angle of 10 degrees is 12.9 degrees). The gas injection condition used in these experiments disturbed the flow field upstream of the injection point to such an extent that the thickness of the shocked flow at the point of injection was larger than the no-injection case by a factor of approximately two. The conical shock angle in the case of injection increased to approximately 19 degrees, and a variation in this shock angle of approximately 1 degree was observed during the nominally steady, facility run time.

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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)
Refereed: Yes
Item Status: Live Archive
Additional Information: Deposited in accordance with the publisher's copyright policy (SPIE)
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - Department of Mechanical and Mechatronic Engineering
Date Deposited: 15 Sep 2011 08:08
Last Modified: 15 Nov 2011 23:37
Uncontrolled Keywords: Cranz-Schardin; digital still cameras; flow field upstream; gas injection; gun tunnel; high-current pulse; hypersonic cone; LED light source; LED pulsed light source; Queensland; runtime; Schlieren flow visualization; shock angle; system development; system use; unsteady shocks; video devices; visualisation
Fields of Research : 09 Engineering > 0901 Aerospace Engineering > 090106 Flight Dynamics
09 Engineering > 0915 Interdisciplinary Engineering > 091508 Turbulent Flows
09 Engineering > 0901 Aerospace Engineering > 090107 Hypersonic Propulsion and Hypersonic Aerodynamics
Identification Number or DOI: 10.1117/12.822032

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