Formation of a heavy particle curtain*

In studies of shock-driven flows of multiphase media, an initial condition that is commonly produced involves a particle-seeded curtain of finite thickness, which is gravity-driven and can have planar or initially perturbed interfaces. We investigate the process of formation of such a curtain, to provide detailed data for numerical modeling, to develop and validate diagnostics, and to study the relevant physics. As our observations show, even for a relatively modest volume fraction of the particles (above 1%), the flow is heavily dominated by the particle dynamics, and the average velocity magnitude is nearly quadratic as the function of the downstream distance. At the same time, the front of the forming curtain manifests evolving perturbations which could be considered in the context of the new class of acceleration-driven multiphase flow instabilities.