Effect of duct geometry on shock wave discharge

Abstract

This paper describes computational work to understand the unsteady flow-field of a shock wave discharging from an exit of a duct and impinging upon a flat plate. A flat plate is located downstream, and normal to the axis of the duct. The distance between the exit of the duct and flat plate is changed. In the present study, two different duct geometries (i.e., square and cross section) are simulated to investigate the effect of duct geometry on the un-steady flows of a shock wave. In computation, the total variation diminishing (TVD) scheme is employed to solve three-dimensional, unsteady, compressible, Euler equations. Computations are performed over the range of shock Mach number from 1.05 to 1.75. Computational results can predict the three-dimensional dynamic behaviour of the shock wave impinging upon the flat plate. The results obtained show that the pressure increase generated on the plate by the shock impingement depends on the duct geometry and the distance between the duct exit and plate, as well as the shock Mach number. It is also found that for the duct with cross-section, the unsteady loads acting on the flat plate are less, compared with the square duct.

On the Unsteady Shock Wave Interaction with a Backward-Facing Step: Inviscid Analysis

“…Axisymmetric geometries are prevalent in the literature [8][9][10][11] , and are usually open ends of shock tubes (open) [12][13][14][15][16] or a larger tube joined to a smaller one (confined). Examples of discontinuous rectangular area enlargements [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] include expansion chambers [17][18][19] , adjoining square cavities 20,21 , open squareshaped or diamond-shaped ends of shock tubes [22][23][24][25][26][27] , and confined rectangular tubes [28][29][30][31][32][33][34] . These works qualitatively and quantitatively comment on the diffracting shock shape, corner vortex location, shock-vortex interactions, and secondary shock structures.…”