Local and total heat transfer on a sphere in a free molecular ionised gas flow

The calculation has been done for orbit-motion-limited conditions, for charged-particle speed ratios S=u/(2kT/m) 1/2 from 0 to 7, and for chi p =e phi p /kT i from 0 to -50, where phi p is sphere surface potential. Result show that: (i) for the front axial point, the local heat flux may be a non-monotonic function of speed ratio and increases with increasing attracting potential - chi p ; (ii) the non-monotonic dependence of the local heat flux to the speed ratio can also be found up to position theta =90 degrees referred to the front axial point ( theta =0 degrees ); (iii) for the rear axial point, the local heat flux is a continuously decreasing function of speed ratio; (iv) for ion retarding potentials, chi p >0, the total heat flux decreases with increasing chi p .