THEORY FOR THE FREE MOLECULE IMPACT PROBE AT AN ARBITRARY ANGLE OF ATTACK

摘要

A theoretical analysis was made of the behaviour of the free molecule impact pressure probe at an arbitrary angle of attack. The solution is formulated in terms of three parameters which represent the tube geometry, the free stream gas velocity and the tube angle of attack to the flow. A drifting Maxwell an motion of the gas molecules entering the tube and diffuse reflection from the tube wall are assumed. Calculations were made for angles of attack up to 90°, for speed ratios from zero to infinity, and for tube geometries varying from an orifice to an infinitely long tube. Graphs and data are presented at the end of this report.