The flow generated inside a duct after it expels a shock wave

The flow field that evolves inside a duct upon the departure of a shock wave from its open exit is studied experimentally. The present investigation covers a relatively long time period, almost until the shock-induced flow inside the duct ceases. During the investigated time period, the appearance of a second shock wave is observed inside the duct. The effect of introducing a door inclined to the duct's exit plane, on the pressure field developed behind the second shock is reported. Three different inclination angles are studied, 30°, 45°, and 90° relative to the duct's exit plane. It is shown that keeping the exit door at different angles and, thereby changing the size of the exit area, has a direct effect on the pressures prevailing inside the tube and on the exit door. The highest pressure on the door and the lowest pressure behind the second shock wave are observed when the exit door is kept at an angle of 30°.