A numerical investigation of shock propagation in three-dimensional microducts

摘要

In the present work, shock propagation and attenuation in three-dimensional microducts with rectangular cross-sections of differing aspect ratios are numerically investigated. The simulations are performed using the Navier-Stokes equations with no-slip wall boundary conditions. The post-shock flow in such microducts resembles a pipe flow, with the extent of the boundary layers comparable with the lateral dimension of the duct. The shock attenuation data are explained on the basis of the viscous dissipation characteristics in the post-shock flow-field, in addition to the behaviour of the boundary layers. It is shown that the three-dimensional effects are adequately modelled using a two-dimensional axisymmetric model or a two-dimensional model, depending on the aspect ratio of the microduct. The data for the shock attenuation are presented in the form of correlations involving the initial Mach number of the shock and a dimensionless parameter that includes the characteristic Reynolds number and the dimensionless shock travel.