Unsteady Boundary Layers on Vibrating Spheres in a Uniform Stream

Abstract

The influence of radial vibrations on forced convection from a sphere placed in a uniform stream of an incompressible fluid is studied mathematically. Consideration is given to first‐order perturbations of the harmonic vibrations of the spherical surface for both high and low frequencies. Theoretical results are obtained by means of a Kármán‐Pohlhausen method for velocity and temperature distributions, skin friction, heat‐transfer rate and the shift in the separation point of the boundary layer. Numerical calculations are carried out for boundary‐layer thickness and velocity profiles in the fluctuating boundary layer.