Numerical Simulation of the Shock Wave Interaction with a Near-wall Fine Particle Layer

The dust explosion prevention in mines and dusted industries has been an important issue for years. During this time, many experimental and theoretical investigations have been carried out. Nevertheless, up to now nobody can declare that all the mechanisms are clear and the comprehensive mathematical model is constructed taking into account all the details of this complicated process. The gas-dust mixture formation behind a shock wave travelling along the dust layer was investigated experimentally by A.A. Borisov et al [1]. In this work, the dust lifting was related to an action of the compression and expansion wave system formed by multiple sequential reflections of the leading shock from rigid wall and contact surface. The simple linear mechanistic model was proposed [2] to explain the experiments that given consistent results. The similar wave picture was obtained in numerical simulations by A.L. Kuhl et al [3, 4] and H. Sakakita [5]. The present paper focuses on numerical simulation of wave processes observed in nearwall fluidized layer under action of normal shock wave. The unsteady process of interaction is described for various shock wave intensities and layer densities. It is shown that shock wave intensity increases significantly in the dense layer, and the gain factor does not depend on the shock wave Mach number and defined only by the density ratio. Two different schemes (regular and Mach) of shock reflections are observed in computations that lead to a principally distinguished scenarios of instability development in a dusty layer.