In the present study, the influence of thermal and diffusion boundary conditions on the structure of laminar diffusion flame in air flows with porous hydrogen blowing was examined. A comparison between the following boundary conditions was attempted: either the porous-surface temperature was assumed to remain lengthwise constant, const TW=const, or the temperature of the fuel supplied through the porous wall was assumed lengthwise uniform, T'=const . The first situation is the case with a liquid fuel injected into flow, for which the evaporating-surface temperature is known to remain constant. With a gaseous fuel injected, the regime with T''=const is ormally encountered. It is shown that the combustion results in a substantial reduction of the wall friction and in a growth of wall heat fluxes. A change in boundary conditions results in a dramatic reconstruction of the boundary-layer flow; it, however, weakly affects the relative laws of friction and heat and mass transfer at laminar flow regime.
展开▼
