Numerical Study of Buoyancy-Opposed Wall Jet Flow

Abstract

This paper describes a numerical study of the flow and thermal fields for opposed wall jet. The hot water injected from plane jet down one wall of a vertical passage of rectangular cross section into cooled water which moves leisurely to the upper. The flow is assumed to be two dimensional, steady, incompressible and turbulent. The finite volume scheme is used to solve the continuity equation, momentum equations, energy equation and κ-e model equations. The flow characteristics were studied by varying of Richardson number (0.0 ≤ Ri ≥ 0.052) and the ratio of back ground velocity to jet velocity (0.05 ≤ R ≤ 0.15). The results showed that, the buoyancy limited the downward penetration of the jet and its lateral spread when Richardson number increased. The shear layer formed at the interface between the two flow streams, and it becomes more concentrated at higher values of Richardson number. In this region, the intensity of the turbulence became stronger and the turbulent shear stress was a minimum value. When the velocity ratio increased, the penetration of jet decreases, its lateral spreading becomes less. Also the temperature difference decreases with the velocity ratio increases. The numerical results give good agreement with the experiment data of Ref. [1].