The present paper describes experimental and numerical investigations of a new boundary condition at an open end of a tube, in which a weak shock wave is discharged towards the surroundings. Experimental and computational investigations were performed on a simple shock tube with and without baffle plates. A numerical calculation was carried out for an unsteady, axisymmetric, inviscid, compressible flow. The size of baffle plate was varied in order to understand its effect on the reflection of the weak shock wave from the open end of the tube. With and without a baffle plate, the results of the experiment were in good agreement with those of numerical calculations. The results showed that an open end correction is subject to the presence of a baffle plate at the open end. An improved empirical equation for the reflection of the weak shock wave from the open end of a duct with and without a baffle plate was developed.

Pseudo-shock is often encountered in a variety of internal flows, almost always entailing an increase in total pressure loss, hence leading to deterioration of the flow system performance. This pseudoshock is a very complex process still requiring a good deal of elucidation. In spite of the recent rapid progress that has been made in numerical computation methods, there is as yet no quantitative prediction of pseudo-shock flow. The present paper describes a simple pseudo-shock flow model using a mass-weighted averaging technique. The flow quantities across pseudo-shock were analysed for different Mach numbers, flow confinements and turbulent boundary layer Reynolds numbers. The analytical results agree well with the previous experimental data. The flow model presented can be used to estimate the important features of pseudo-shocks in engineering practice.