Jet loads on a plate with different Knudsen numbers

This short note presents investigations on two sets of coefficients for gaseous jet loads at an inclined flat plate. These load coefficients are derived at the collisionless flow limit. The plate surface can be diffusive or specularly reflective. The coefficients include total pressure, friction, heat flux, moment, and the distances from the force to the plate centers. Direct simulation Monte Carlo simulations are performed to obtain the numerical coefficient results. When the Knudsen (Kn) number is large, e.g., Kn > 1, those coefficients are close to the exact solutions; when the Kn number is small, e.g., Kn < 1, there are minor deviations. These coefficient formulas can provide quick references for the loads within a wide range of Kn numbers, and they can significantly reduce simulations and measurements.