The Effect of Vorticity Flux on the Convection Heat Transfer to the Unsteady Separation Bubble on a Spinning Sphere

摘要

Initial development of the laminar thermal boundary-layer flow over an impulsively started translating and spinning isothermal sphere is investigated. Velocity components and temperature are expanded in series in powers of time. Leading and first order functions are obtained analytically and the second order functions are determined numerically. Following the onset of separation, temporal developments of the circulation along the dividing streamline enclosing the separated region and heat transfer to the separation bubble are determined. The circulation around or the vorticity flux through the separated region is found to increase the heat transfer to this region.