Interaction between the Unsteady Boundary Layer and Inviscid Hot Flow in a Shock Tube

Abstract

A numerical calculation is presented for the flow in a low-pressure shock tube. The evolution of the hot flow quantities due to mutual interaction between the boundary layer and inviscid hot flow are taken into account. A better knowledge of the unsteady evolution of this hot flow is so obtained, including the distribution of all parameters at the limiting regime. The computational results, with Argon as a driven gas, are in agreement with the different experimental results at usual measurement stations. Nomenclature= sound velocity = shock tube diameter = enthalpy = separation distance between shock and contact surface = maximum separation distance = mass loss term = shock Mach number = pressure = Prandtl number = shock tube radius = perfect gas constant = entropy = temperature = axial flow velocity = flow velocity = shock velocity = U S -(7= flow velocity in a shock-fixed coordinate system = radial flow velocity = laboratory coordinate system = density ratio across the shock = ratio of specific heats = boundary-layer thickness = displacement thickness T TH = density displacement thickness • = density = viscosity = test time = maximum test time = test time in ideal shock tube theory Subscripts c = conditions at the contact surface e = conditions in the inviscid hot flow / = conditions from ideal shock tube theory £ = conditions at the limiting regime S = conditions immediately behind the shock wave W = conditions at the wall 1 = conditions in the undisturbed flow ahead of the shock