An approach for simulating the transport of spherical particles in a rarefied gas flow via the direct simulation Monte Carlo method

An approach is presented for computing the force on and heat transfer to a spherical particle from a rarefied flow of a monatomic gas that is computed using the direct simulation Monte Carlo (DSMC) method. The particle concen tration is taken to be dilute, and the gas flow around the particle (but no t necessarily throughout the flow domain) is taken to be free-molecular. Gr een's functions for the force and heat transfer are determined analytically , are verified by demonstrating that they yield certain well-known results, and are implemented numerically within a DSMC code. Simulations are perfor med for the case of gas confined between two parallel plates at different t emperatures for broad ranges of pressures and particle velocities. The simu lation results agree closely with analytical results, where applicable. A s imple approximate expression relating the thermophoretic force to the gas-p hase heat flux is developed, and the drag and thermophoretic forces are fou nd to be almost decoupled for a wide range of particle velocities. (C) 2001 American Institute of Physics.