Dust Collection Efficiency for Power Law Bodies in Hypersonic Flight

Abstract

A numerical and analytical study predicts 1) the collection efficiency of conical and blunted axisymmetric bodies of the power law family in hypersonic flight through dust clouds and 2) the impact angle and velocity. Collection efficiencies of cones using the exact conical flovvfield solutions are shown for particles obeying a drag law of the form C'D = fn(Re, M, T p/T). Most of the data can be correlated by three dimensionless groups. Results show large variations from collection efficiency based on the less realistic standard drag law CD=fn(Re). Collection efficiency of power law bodies has been determined in the hypersonic slender body approximation for the realistic drag law. The data correlate well with the three aforementioned dimensionless parameter groups. Blunting is found to decrease collection efficiency appreciably. An approximate model provides a qualitative description of the collection efficiency and impact angle dependence on the main parameters. The distribution of impact angle for cones and blunt bodies also correlates well with the three dimensionless groups. In all cases, the impact velocity is nearly equal to the flight velocity.