Mixing and combustion of fuel jet in pseudo-shock waves

A plasma jet of nitrogen or hydrogen/nitrogen mixture was injected into an unheated supersonic airstream. Pseudo-shock waves were produced due to heat added by the plasma jet itself and combustion of hydrogen in it. The gas composition, pitot pressure, and stagnation temperature distributions at the duct exit section as well as the wall pressure distributions were measured. They were different from those obtained with pseudo-shock waves produced by mechanically increasing the back-pressure. The schlieren photographs and other measurements clarified that the pseudo-shock wave in the present experiment was produced by the separation of the boundary layer on the opposite wall due to impingement of the bow shock wave of the plasma jet. The establishment of the pseudo-shock wave was achieved when its first wave went upstream of the plasma torch.