NATURAL CONVECTIONS IN CONJUGATED SINGLE AND DOUBLE ENCLOSURES

The natural convection in single and double conjugated enclosures are numerically investigated. The single and double enclosures are formed by low conductance walls with finite thickness. The outside vertical s urfaces of the conducting walls are of the third kind of boundary cond ition while the top and bottom outside surfaces are adiabatic. The pro blem studied is characterized by a dominant horizontal temperature gra dient and the thermal boundary conditions at the cavity surfaces can n ot be specified in priori. Numerical results reveal the characteristic s in such kind of enclosures and show the importance of the thermal bo undary conditions on the natural convection in enclosures. It is also found that the natural convections in the conjugated double enclosures are basically the same, with a major difference in their fluid temper ature levels.