Quench subcooled-jet impingement boiling: Two interacting-jet enhancement

Enhancement resulting from interaction of two adjacent jets impinging on largely superheated stainless steel plate (900 degrees C, initial induction heating) is recorded and analyzed with inverse-conduction analysis and high-definition visualization. Subcooled water jets (20 degrees C, 1 atm, Reynolds number 1.5 x 10(4)) with varying jet separation distance W (up to 30 nozzle diameters of DO show that the spreading liquid wetting fronts merge and the heat transfer coefficient increases substantially in the merged region, which follows an elapsed time of isolated-jet behavior. This enhancement is presented as the time-dependent two-jet cooling effectiveness with a peak of 1.6 (60% enhancement) for W/D-n =10 at t = 3 s, followed by decay. This enhancement decreases with increasing D-n, but overlapping jets create some enhancement for all jet separations. In the interaction region, the plate undergoes rapid temperature drop (by lateral conduction toward the jet centers), reaching large cooling rate of 600 K/s. (C) 2018 Elsevier Ltd. All rights reserved.