Abstract:  

A non-continuum gaseous flow out of an annular exit impinging on a vertical diffused flat plate was investigated. This study focused on the properties of stagnation point of the plate surface. A constraint relation about the velocity components of gas particles leaving a nozzle exit point and arriving at a given spatial point outside the nozzle was employed. This relation leads to several analytical expressions for collisionless flow property distributions on the plate surface. Effects of Knudsen number, speed ratio, and vertical distance between nozzle exit and plate center in the stagnation properties were studied. Numerical simulation results obtained with the direct simulation Monte Carlo method validate the analytical collisionless flow.