Effect of Inlet Slot Dimension on Laminar Plane Wall Jet Flow over an Obstacle

In this paper, the effect of the inlet slot dimension of a plane laminar wall jet on the formation and growth of recirculation and on the velocity profiles are investigated numerically when the jet is allowed to flow over an obstacle. Wall jet from the nozzle exit blows tangentially through the inlet slot along the bottom wall where the solid obstacle is present. The top and right side of the domain is kept open whereas the left side of the domain is bounded by a solid wall. Two-dimensional incompressible laminar flow is assumed. Continuity equation and momentum equation for the full computational domain are solved numerically by using an inhouse CFD code based on stream function vorticity formulation. Simulations are carried out for different inlet slot heights and a range of Reynolds numbers. From the streamline pattern, it is observed that the increase in size and shape of the recirculation is more when the inlet dimension is increased. Investigations are extended to find the influence of slot dimension on stream-wise velocity profile in the upstream and the downstream locations. It is established that the maximum value of stream wise velocity component increases as the inlet slot height increases. These effects are more reflected on higher values of Reynolds numbers.