Onset of convection in a fluid saturated porous layer overlying a solid layer which is heated by constant flux

Onset of convection in a fluid-saturated porous layer above a solid layer heated by constant flux is discussed. Thermoconvective stability of a porous layer over a solid layer is important in ocean floor hydrothermal systems and thermal insulation problems. The critical Rayleigh number for the porous layer increases with solid-layer thickness. That is the reverse of the case for constant-temperature heating. Topics include the impermeable top and constant-pressure top cases. Results are compared to those of R. McKibbin et al., 1983.