Based on the principle of dependence of the intensity and the spectrum
of the spontaneous light emitted in an electrical discharge on the de
nsity and the temperature of the gas along the discharge path, a techn
ique for flow visualization around the bodies flying at hypersonic Mac
h number is developed, The shock shapes over a flat plate with sharp l
eading edge at different angles of attack are visualized using this te
chnique in IISc hypersonic shock tunnel HST1 at flow Mach number of 5.
75. The visualized shock wave angles match very well with the theoreti
cal values, The details of this new technique along with a few sample
results are presented here.