Numerical investigation of distribution of reaction rate during convective heat transfer with endothermic chemical reaction

Abstract

The reaction rate for thermal chemical reaction is an intensive quantity characteristic of process, and reflects the general influence of such factors as heat transfer and mass transfer on the chemical reaction. The distribution of reaction rate during convective heat transfer with endothermic chemical reaction in channel was numerically investigated using a 2D model. Simulation results indicated that there was a layer distribution of reaction rate in the flow field, which was similar to a thermal boundary layer. The reaction rate near wall was much higher than that in the core flow region, and there was a dramatic increase in reaction rate in the very thin layer near the wall. Moreover, the distribution of reaction rate was affected by the negative feedback effect of transformations of mass and energy. The distribution of reaction rate, which was contrary to the thermal boundary layer, could be eventually obtained because the distribution of reaction rate could change over a short distance once the heat absorbed by reactant was less than the internal energy transformed into chemical energy.