Experimental study of external lateral flow effects on turbulent isothermal upward/downward slot jets impinging inside an open cavity

In this work, the flow within an open cubical cavity with an inlet vertical planar jet exposed to an external lateral flow is studied experimentally using stereoscopic time-resolved particle image velocimetry (TR-PIV). The turbulent structure in the near field of the planar jet issuing perpendicularly from a rectangular slot nozzle is evaluated for both vertically upward and downward directions of the discharged jet. For both flow configurations, the jet discharge rectangular nozzle spans 30% of the cavity span leaving a clearance between the jet edge and sidewalls. The working fluid is water, and the complex dynamics of the three-dimensional (3D) flow field is investigated for fixed lateral flow Reynolds number of Re=3000 and three nozzle exit Reynolds numbers based on the mean streamwise exit jet velocity and nozzle hydraulic diameter of Re_j=1500, 3000 and 5000. The spatial development and structure dynamics of the shear interface instability are analyzed in planes normal to the cavity roof. Flow visualization images of the mean and fluctuating velocity, vorticity and shear strain rate distributions are obtained for upward and downward directions of the slot jet, and spectral analysis of the oscillating instability is performed to describe and quantify the strong shear layer interactions that take place between the discharged eddies of the splitting jet and the external lateral flow.