Abstract
The effects of shock generated vorticity and mass transfer on stagnation point heat transfer rates are investigated. The complete incompressible Navier-Stokes equations are considered in the flow region between the bow shock and the surface of spheres and cylinders. Boundary conditions are applied immediately behind the shock and at the wall. The numerical solutions to the flow equations with air injected into the shock layer, show tha t the interaction between the vorticity generated by the wall and by the curved shock reduces the effectiveness of mass transfer cooling. The reduction in heat transfer rates due to mass injection is substantially less than predicted by boundary layer theory at Reynolds numbers below 10 for spheres and 10 for cylinders. The heat transfer rates with mass injection were found to be 200 to 300 per cent greater than corresponding boundary layer values for the extreme cases investigated (strong shock, Re = 10 and large air injection rates). These heat transfer rates are, however, less than the zero mass injection values. It is also shown for a sphere and for Pr =1 .0 tha t the increase in heat transfer is primarily dependent on the inverse of the difference between the vorticity at the wall and the vorticity immediately behind the shock.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call