Modeling and simulation of particle dispersal by shock and detonation waves

Particle dispersal by shock and detonation waves is an interesting and important phenomenon that can be observed in nature, such as in volcanic eruptions, and industrial applications, such as in detonation of multiphase explosives. This problem is difficult to investigate experimentally, because experiments are hazardous and expensive and the maximum velocities, pressures, and temperatures are very high. Therefore, the modeling and simulation approach employed in this dissertation is an attractive alternative. However, there are numerous challenges in modeling and simulating this problem. The problem involves multiple phases. Because shock and detonation waves and contact discontinuities exist in the flow, the phase interaction becomes much more complicated than in conventional multiphase flows because the unsteady mechanisms can become important. The problem also involves multiple scales. For the small scales that cannot be resolved, modeling techniques are required to capture the physics in these scales and their interactions with resolved scales. The modeling and simulation approach pursued in this dissertation is important because it can improve our understanding of how to predict particle dispersal by shock and detonation waves, and because it can lead to practical guidelines.;In this dissertation, we develop a rigorous simulation approach for unsteady compressible multiphase flow involving shock and detonation waves, and apply this approach to investigate a sequence of problems of particle dispersal by shock and detonation waves. First, the particle dispersal in a one-dimensional shock-tube is considered. The primary focus is on how the existence of particles causes the flow to transition from the frozen to the equilibrium limit. The second problem entails the investigation and resolution of numerically induced particle-number-density fluctuations in Eulerian-Lagrangian simulations of multiphase flow. Guidelines to reduce the amplitude of the fluctuations are proposed that can be easily applied in practice. The third problem considered in the dissertation is the modeling and analysis of particle interaction with shock and blast waves. The study clearly demonstrates the importance of the unsteady force and heat transfer in the interaction of particles with shock and blast waves. Finally, we consider the problem of particle dispersal by blast waves. The focus is on investigating the interactions between particles with the complex wave system. The unsteady contributions to force and heat-transfer are again found to be substantial.