Flash X-Ray Radiography for the Density Measurement in a Hypersonic Air Flow

Abstract

Soft X-ray radiograph method using a flash X-ray tube was developed as a means of measuring air density in a hypersonic flow in a shock tube. The method was applied to the measurement of the density distribution between a circular cylinder and the detached shock wave at a free-stream Mach number of 5.5 and a free-stream density of about one-tenth of the normal atmosphere. Results suggest that the method is promising for the investigation of hypersonic flow fields, especially for the measurement of narrow regions with steep density gradients, because the effect of refraction can be neglected without error in the wavelength range of X-rays.