Propagation of Shock Waves in Dilute Bubbly Liquids : 3rd Report, Effect of Spatial Distribution of Bubbles

Abstract

Transient shock wave phenomena in a liquid containing noncondensable gas bubbles are investigated experimentally and numerically. In the experiment, time evolution of the shock wave is measured using two vertical glass shock tubes with different diameters : 18 mm and 52 mm. In the numerical simulation, thermal processes inside each bubble are directly calculated by using full equations for mass, momentum and energy conservation, and the results are combined with the averaged conservation equations of the bubbly mixture to simulate the propagation of the shock wave. Initial spatial distribution of the bubbles is also taken into account. The numerical results reveal that the spatial distribution greatly affects the structure of the shock wave, such as the pressure peak of the shock front and the period of the relaxation oscillation. The present numerical results agree very well with the experimental results, when the bubbles are not distributed uniformly and are relatively concentrated along the axis of the shock tube. However, the experimental data are much different from the numerical results obtained using a uniform spatial distribution of the bubbles.