In-tube shock wave compression by piston effect of unsteady jet

Abstract

A high-pressure field is generated in a circular tube by introducing an unsteady jet from its open end. The head of this jet acts as a piston, driving compression waves ahead of it. The peak value of the induced overpressure is evaluated as a solution of a Riemann problem, wherein the jet head is equivalent to a piston head. The jet head of the driver gas, with a filling pressure of 400 kPa, is equivalent to a piston head moving at 160 m/s. This highpressure generation scheme through the "piston effect" is useful for industrial applications, including filter cleaning in dust collectors, and as an interesting example of unsteady, compressible fluid dynamics.