An experimental analysis on the coupling effect of centerwall location and side walls orientation on impinging flow jets

ABSTRACT The work aims at understanding the effect of coupling of central wall location and side walls orientation on flow characteristics of an impinging flow jet. The study experimentally intends physical insight into heterogeneous phenomena of efflux from a small opening impinging on a surface confined from three sides under deviant conditions. Systematic experiments were performed on a cascade tunnel with flow ejected at a velocity of 36 m/s. Results show that outside the core region, the flow experiences a monotonic reduction with increase in distance along streamline and radial direction. The flow features vary distinctly with three wall configurations than conventional wall jet. The centerwall location is more efficient in bringing substantial change when placed closer to the exit (low velocity losses) and primarily governs the chances of strong flow deflection or back flow losses. However, wall placed far away from exit results in diminishing returns with a critical value beyond which the flow characteristics become insensitive. The presence of walls on sides results in reduction in the core region. The geometry was noted to influence the entrainment of ambient fluid, the spread of the shear layer and the length of the potential core.