NUMERICAL STUDY OF MIXED CONVECTION HEAT TRANSFER THROUGH DOUBLE SQUARE CAVITY CONNECTED WITH EACH OTHER

Abstract

A numerical analysis is carried out to study the performance of mixed convection in a two square cavity connected one with other using finite element method with software package (FlexPDE). An external fluid flow enters the first cavity through an opening, fixed in the left vertical wall of the first cavity then passes through a second cavity and exits from other opening in the right vertical wall of the second cavity. The boundary conditions of the connected walls between the two cavities are maintained at a constant temperature (isothermal) while the other walls are adiabatic. In the present study streamlines, isotherms, average temperature and average Nusselt number of the heated walls are reported for a range of Richardson number 0 ≤ Ri ≤ 10, Reynolds number 50 ≤ Re ≤ 200, aspect ratio of heated walls, 0.1 ≤ Ho ≤ 0.9 and different exit port positions Ho1= 0.1, 0.5 and 0.9 for a constant position of inlet port Hi=0.2 while Prandtl number is taken as Pr=0.71. The results of streamlines, isotherms, average Nusselt number and average temperature are compared with available result and excellent agreement has been achieved. The numerical results indicate that the rate of heat transfer is significantly depends on the rate of height of the heated walls (Ho), (Re) and (Ri) also the results show that the location of the exit port do not has important effects on the rate of heat transfer and with increasing Reynolds and Richardson numbers the convection heat transfer becomes predominant over the conduction heat transfer.