Particle sampling in supersonic streams with a thin-walled cylindrical probe

Abstract

The theoretical collection efficiency of a thin-walled cylindrical probe has been determined for nondiffusing particles of low concentration suspended in a supersonic stream. It is demonstrated that the probe capture efficiency is influenced by particle inertia, departures from Stokes drag, gas compressibility, and the probe ingestion rate. By defining an effective Stokes number in terms of the particle stopping distance downstream of the shock, which includes the effects of non-Stokesian drag and slip flow, and rescaling the Stokes number with the shock detachment distance, the reduced probe collection efficiency is shown to be correlated with a single universal curve. This similarity parameter should be useful in attempts to correlate the particle deposition for any geometry in a supersonic stream.