Molecular dynamics simulation of a rarefied gas flow past a sphere
Abstract
The purpose of the present study is to clarify the points to be overcome for applying the molecular dynamics method to flow phenomena, especially a flow past an obstacle. For this purpose, we here focus the investigation on a subsonic flow of a rarefied gas around a sphere. The results of the simulations show that the influences of the boundary condition can be neglected, and that the drag coefficient agrees well with the analytical value of the free molecule flow if the simulation region is sufficiently large. However, since the CPU times roughly increase in proportion to the square of the number of molecules with enlargement of the simulation region, we need some new techniques for the successful application of the molecular dynamics method to a flow around an obstacle: a new boundary condition which does not distort the flow field even if a small simulation region is used, and a new algorithm where the speedingup techniques used in simulations of liquids are applicable.
 Publication:

JSME Transactions
 Pub Date:
 January 1992
 Bibcode:
 1992JSMET..58...79S
 Keywords:

 Gas Flow;
 Molecular Flow;
 Rarefied Gas Dynamics;
 Spheres;
 Subsonic Flow;
 Boundary Conditions;
 Computerized Simulation;
 Drag Coefficients;
 Flow Distribution;
 Fluid Mechanics and Heat Transfer