Experimental study of the hydrodynamics of a supersonic steam jet impinged on a wall in vertical and oblique orientations

In this work, a supersonic steam jet was impinged on a wall in vertical and oblique orientations by varying the angle from 90 degrees to 60 degrees and at varying total inlet pressure ranging from 1.5 to 3.0 bars. In the vertical impingement, the stagnation point was found to move towards the wall. The steam's jet profiles show self-similarity to some extent (2 to 3 r/D), where the contours across some spatial limits were found to be devoid of any high-value velocity variation contours. The overall mainstream and the fluctuating velocities showed a slight spreading trend (9-14 r/D-N) with a rise in the total inlet pressure. In oblique impingement, the misalignment between the nozzle axial axis and the steam jet axial axis is reduced. Initially, this misalignment may be attributed to the mounting configuration of the nozzle with the wall horizontal axis as well as to the action of gravity. The growth rate and decay rate trends in the upper, middle, and lower layers of the flow show slight dependence on the variations in the total inlet pressure. The rise in the total inlet pressure causes variations in the growth rate ranging from 1.6 to 3.0. Similarly, the decay rate varies from -0.19 to -0.275. The turbulence kinetic energy (TKE) and the turbulence production values were found to be higher in the top layer where Kelvin Helmholtz instabilities were generated across the steam-water interface. The turbulence dissipates in the lower wall region, which may be attributed to the dissipation due to the quenching by the wall, which reduces the scale of the vortices that exist within the layer.