Monte Carlo Simulation of the Flow of a Rarefied Gas Around a Cylinder

A Monte Carlo technique is described for simulating the high-speed flow of a rarefied gas around a cylindrical body. The method uses a hard-sphere model, or, alternatively, the "Maxwellian" model to compute collisions between particles. A representative "test particle" is scattered in such a way that its statistical behavior approximates that of a random particle chosen from the actual gas. This requires knowledge of the distribution function of "target" particles, which is estimated from observations of the behavior of the test particle. The method is applicable to any collision model and to any model for the interaction between the gas and the surface of the body. Accepted for the Air Force Franklin C. Hudson Chief, Lincoln Laboratory Office