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This book consists of three major components: gas kinetic studies of vacuum chamber facility effects on the background flows; theoretical studies on collision-less free plume flow out of different exits. These analytical solutions are validated with numerical methods; and simulations of plasma and neutral plume flows from a cluster of Electric Propulsion (EP) Hall thrusters into low pressure background with the direct simulation Monte Carlo (DSMC) and Particle-In-Cell (PIC) methods. The last part adopts two electron models are used, the Boltzmann relation and a detailed electron model. A a general finite element solver working on unstructured mesh is developed to solve the generalized Possion´s equation for the electron properties. This is a practical engineering book which contains several pieces of seminal work which inspires researchers from both academia and industry, including communities of rarefied gas dynamics; vacuum sciences and industry; aerospace and space engineering, such as propulsion and electric propulsion, spacecrafts and rockets.

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Dr. Cai has two M.S. degrees (Fluid Dynamics, CAS, 1997; M.E., Cornell Univ., 1999); one Ph.D. degree (A.E., UMich, 2005). He worked as a software engineer (Altair Engineering Inc., 1999-2005) and a research scientist (ZONA Technology, Inc., 2005-2008). Currently he works as an Assistant Professor in the MAE Dept., New Mexico State University.

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