HEAT AND MASS TRANSFER IN AN ARRAY OF RODS IN THE APPROXIMATION OF POROUS MEDIUM
A review of heat and mass transfer in porous structure such as fuel bundle is presented. Problems of averaging equations of heat, mass transfer and turbulence model are considered. An analysis of the research results is described further. In order to establish communication type of average heat and momentum fluxes with average temperature and velocity of the fluid, one could use the theory of matrix polynomials. A vector characterizing the direction of flow and a degree of orientation of a porous media are used as the communication argument. The resistances tensor which linking the resisting force with the velocity vector can depend on the attack angle. A form of the tensor of effective thermal conductivity of the coolant flow through a fuel assembly was obtained. The tensor contains four parameters, which represent the effective thermal conductivity coefficients under certain combinations of the flow velocity vector and temperature gradient with respect to the axis of a fuel assembly. A correlation between the tensor of effective stresses and the field of average velocities was established. The correlation contains three effective viscosity coefficients. To close the averaged equations the authors suggest using an integral turbulence model because by means of this model one could obtain the effective coefficients of momentum and heat transfer. Particular attention is given to the discussion of further research activity.