Aerodynamics of Two Side-by-Side Plates in Hypersonic Rarefied-Gas Flows

Hypersonic rareŽ ed-gas  ows near two side-by-side plates have been studied numerically with the direct simulationMonte Carlo technique under transitional rareŽ ed-gas- ow conditions (Knudsen numbers from 0.024 to 1.8). Strong in uences of the geometrical factor (ratio of distance between plates to plate length) and the Knudsen number on the  ow structure (the shape of shock waves, the conŽ guration of subsonic  ow zones), skin friction, pressure distribution, lift, and drag have been found. For small geometrical factors, the repulsive lift force becomes signiŽ cant with a lift–drag ratio of 1.7 for near-continuum  ow, but decreases signiŽ cantly (0.4) in the near-free-molecular  ow. Results show that the lift, drag, and lift–drag ratio dependency on the Knudsen number is nonmonotonic for various geometrical factors.