Rotation effect on jet impingement heat transfer in smooth rectangular channels with heated target walls and radially outward cross flow

Abstract

The effect of rotation on jet impingement cooling by an inline array of circular jets in twin channels was studied. Impinging jets were in the direction of rotation in one channel and opposite to the rotation direction in the other channel. The jets impinged normally on the smooth, heated target wall in each channel. The flow exited the channels in a single direction, radially outward, creating cross flow on jets at larger radii. Jet rotation numbers and jet Reynolds numbers were varied from 0.0 to 0.0028 and 5000 to 10000, respectively. For the target walls with jet flow in the direction of rotation (or opposite to the direction of rotation), heat transfer decreased up to 15% (or 20%) as compared to corresponding results for non-rotating conditions. This is because the impinging jets were affected by the rotation-inducted secondary flows produced by Coriolis, buoyancy and centrifugal forces.