Heat transfer enhancement in an impinging jet with a fractal grid at the inlet

An impinging jet with passive control of mixing and heat transfer with the use of a grid at the inlet is numerically studied. It is shown that the local Nusselt number at the stagnation point on the heated surface with which the jet is impinged, and the Nusselt number averaged over the area with intense heat transfer, increase with increasing Reynolds number in accordance with a power law corresponding to the empirical approximation. It is found that addition of a grid, especially fractal grid, leads to noticeable enhancement of heat transfer in the central part of the jet. The results of the previous measurements are compared with effects predicted by the present computations, and the prospects of further investigations are determined.