Cross-sectional concentration of particles during shock process propagating through a gas-particle mixture in a shock tube

For shock wave Mach number smaller than 1.5, a phase mass flow ratio of 0.1-0.5, and particle diameters of 30-50 microns, shock wave forms are studied in a gas-particle mixture of air and glass spheres. Since the relaxation length of the flow is large, the shock tube wave system should be treated as nonsteady in order to account for shock wave decay. The method of characteristics is applied, yielding results that are in good agreement with measurements in the leading zone of the wave. Particle drag, measured by streak recordings, gives a satisfactory continuation of Rudinger's (1970) law, and appears to increase with particle diameter. The number density of particles near the tube wall is found to be almost 50% lower than the density at the center.