Abstract
This paper describes a shock wave propagation in a tube with a sudden area increase at a diameter ratio of 1:2. Experiments were carried out using a diaphragmless shock tube, in which instead of rupturing diaphragms a piston sealing the high pressure chamber and the low pressure channel was quickly moved to drive shock waves. Optical flow visualization using an aspheric lens succeeded to visualize shock waves in this circular cross sectional tube. A numerical scheme developed for this purpose was well validated by comparing its results with interferograms. Shock wave focusing and shock-shear layer interaction behind the transmitted shock wave were clearly simulated by this numerical scheme.
