Visualization of shock wave by using electric discharge

A method of measuring shock waves by using electric discharges was described. The principle of this method is based on the fact that radiation intensities of the electric discharges depend on gas densities. Therefore, the shock shape can be measured by taking a photograph of the discharge column, because the radiation intensity in the shock layer is different from that in the freestream region. Some examples of the shock shape measurement were carried out by applying this experimental principle. The measurements of the lateral shape and cross-sectional shape of an oblique shock wave over a wedge model were presented. These results agreed well with the shock shape determined by the schlieren method.