Numerical solution of stationary conjugate heat-and-mass transfer in laminar flow of dissociating nitrogen tetroxide in a fuel element cluster

Stationary conjugate problem of convective heat-and-mass transfer in laminar flow of nitrogen tetroxide, which streams triangular fuel element cluster longitudinally, has been solved numerically by simultaneous application of the methods of finite elements and finite differences. Calculations show that the chemical reaction rate, which depends on pressure in the channel, affects heat exchange. Heat transfer increases in the presence of dissociation reaction flow in comparison with ''frozen'' case. As a result of diffusional withdrawal of the reaction products into the flow nucleus, gas cooling takes place in the wall region at the expense of heat absorption by reaction which leads to the increase of temperature gradient on a wall and, consequently, to the increase of heat flux. Mass average gas temperature and wall average temperature decrease. The effect of the reaction manifests itself in equalization of temperature drop over the wall perimeter