On the equation of motion of a particle in a fluid under the influence of a large velocity gradient.

Abstract

The development of the Basset integral appearing in the equation of motion of a particle in a fluid is investigated numerically for the flow across an aerodynamic shock. It is found that for this flow the force acting upon the particle described by the Basset integral can be many times larger than the viscous drag, in the immediate shock region. It is demonstrated how this force affectsthe particle motion across the shock for different particles. The results obtained show that it is permissible to neglect the Basset integral for the theoretical description of the motion of the types of particles commonly used in flow measurement tracer techniques for the kind of flow situation considered.