Heat Transfer Characteristics and Optimization of a Porous Radiant Air Heater, Using DOM, under the Influence of 2-D Rectangular Radiative Field

This work presents the heat transfer characteristics of a new type of porous radiant air heater that operates on the basis of effective energy conversion method between flowing gas enthalpy and thermal radiation. At each layer, the gas and solid phases are considered in non-local thermal equilibrium, and combustion in the porous radiant burner is modeled by considering a non-uniform heat generation zone. The homogeneous porous media, in addition to its convective heat exchange with the gas, may absorb, emit, and scatter thermal radiation. In order to determine the thermal characteristics of the proposed porous radiant air heater, a two-dimensional model is used to solve the governing equations for porous medium and gas flow, moreover discrete ordinates method is employed to obtain the distribution of radiative heat flux in the porous media. In order to validate the applied numerical method at the present analysis, the results are compared with some reported theoretical and experimental results of other investigators, where good agreement is observed.