Setchell, Robert E. and Storm, Erik and Sturtevant, Bradford (1972) An investigation of shock strengthening in a conical convergent channel. Journal of Fluid Mechanics, 56 (3). pp. 505-522. ISSN 0022-1120 http://resolver.caltech.edu/CaltechAUTHORS:20120809-091949718
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The behaviour of an initially plane, strong shock wave propagating into a conical convergence is investigated experimentally and theoretically. In the experiment a 10° half-angle cone is mounted on the end of a pressure-driven shock tube. Shock waves with initial Mach numbers varying from 6.0 to 10·2 are generated in argon a t a pressure of 1·5 Torr. During each run local shock velocities a t several positions along the cone axis are measured using a thin multi-crystal piezoelectric probe inserted from the vertex. This technique produces accurate velocity data for both the incident and reflected shock waves. In the corresponding analysis, a simplified characteristics method is used to obtain an approximate solution of the axisymmetric diffraction equations derived by Whitham (1959). Both the shock velocity measurements and the axisymmetric diffraction solution confirm that the incident shock behaviour is dominated by cyclic diffraction processes which originate at the entrance of the cone. Each diffraction cycle is characterized by Mach reflexion on the cone wall followed by Mach reflexion on the axis, These cycles evidently persist until the shock reaches the cone vertex, where the measured velocity has increased by as much as a factor of three. Real-gas effects, enhanced in the experiment by increasing the initial Mach number and decreasing the pressure, apparently alter the shock wave behaviour only in the region near the vertex. Velocity measurements for the reflected shock within the cone show that the shock velocity is nearly constant throughout most of the convergence length.
|Additional Information:||© 1972 Cambridge University Press. Received July 18 1972. Published Online March 29 2006. The authors are indebted to Professor Whitham for suggesting this simplification.|
|Official Citation:||Robert E. Setchell, Erik Storm and Bradford Sturtevant (1972). An investigation of shock strengthening in a conical convergent channel. Journal of Fluid Mechanics, 56 , pp 505-522 doi:10.1017/S0022112072002484|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Ruth Sustaita|
|Deposited On:||09 Aug 2012 16:31|
|Last Modified:||26 Dec 2012 15:54|
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