Mixed convection heat transfer in ventilated cavities with opposing and assisting flows

Mixed convection heat transfer in ventilated cavities submitted to a consta nt heat flux has been numerically studied using the Navier-Stokes equations with the Boussinesq approximation. Results in terms of streamlines and iso therms are produced for different values of the governing parameters, namel y, the Rayleigh number (10(3) less than or equal to Ra less than or equal t o 10(6)) and the Reynolds number (5 less than or equal to Re less than or e qual to 5,000). The geometrical parameters are the aspect ratio of the cavi ty A = L'/H' = 2 and the relative height of the openings B = h'/H' = 1/4. R esults of the simulations show that the maximum interaction between natural and forced convection occurs for couples (Ra, Re) which can be correlated as Re = a Ra-b.