Abstract
The effect of a small protuberance in a boundary layer on the structure of a λ-type pseudo-shock wave was experimentally investigated. The Mach number upstream of the pseudo-shock is 1.80. When the head of the pseudo-shock is located at the protuberance, the pseudo-shock is affected most and it consists of a series of oblique shock waves. In such a flow state, the wavy variation of the pressure distribution along the duct axis is much smaller in comparison with a pseudo-shock wave in the case of no protuberance.
