Estimation of the Particle Drag Coefficients for Compressible and Rarefied Flows Using PIV and MTV Data
In the present study, the particle drag coefficients in compressible and rarefied flows are estimated experimentally. In the experiments, the particle and gas velocities in an underexpanded jet are measured using PIV and MTV techniques. The drag coefficients are calculated from the equation of the particle motion using the PIV and MTV data. The resulting coefficient is situated in the region where compressibility and rarefaction effects are believed to be remarkable. The results reveal that the estimated drag coefficients do not agree with those calculated from a well-known empirical relation including the both effects, but the data fit to a relation similar to the form of the Stokes drag law. That is to say, the experimental drag coefficient is inversely proportional to the particle Reynolds number although the coefficient has been believed to obey the empirical relation.
- 8.J.R. Stadler, V.J. Zurick, NACA TN, 2423 (1951)Google Scholar