EFFECTS OF OUTFLOW BOUNDARY-CONDITION ON CONVECTIVE HEAT-TRANSFER WITH STRONG RECIRCULATING FLOW

Three practices of treating outflow boundary condition were adopted in computations for convective heat transfer of a two-dimensional jet im pinging in a rectangular cavity. The three practices were local mass c onservation method, local one-way method and fully developed assumptio n. The numerical solutions of the three methods were compared with tes t data obtained via. naphthalene sublimation technique. It was found t hat the fully developed assumption was inappropriate, and the local on e-way method could provide reasonably good results for the cavity bott om, while for the lateral wall the results with this method qualitativ ely differed from the test data. The solution with the local mass cons ervation method was the best. It thus suggested that for a problem exp ected with a strong recirculating flow at the exit of the computation domain, the local mass conservation method be adopted to treat the out flow boundary condition.