The Glancing Collision of Two Shock Waves in a Branched Duct

Abstract

The collision of two shock waves of different strengths and initially at right angles to each other at the junction of a branched duct has been followed by schlieren photography and by numerical analysis using a finite difference scheme and also a hybrid method comprising finite elements and finite differences. Because of cost, analyses of the wave patterns have been confined to times that are less than that required for wave action to completely cease in the junction of two ducts. However, it is during the early stages that wave action is important and, therefore, provides a critical test of the numerical methods. The results obtained by both methods have been satisfactory. On the other hand, the sequences of schlieren photographs extend to the time when flow in the junction is steady. Because shock waves of different initial strengths in the two branches have been used there are interesting differences in flow behaviour.