ROTATION EFFECT ON JET IMPINGEMENT HEAT-TRANSFER IN SMOOTH RECTANGULAR CHANNELS WITH HEATED TARGET WALLS AND RADIALLY OUTWARD CROSS-FLOW

The effect of rotation on jet impingement cooling by an inline array o f circular jets in twin channels was studied. impinging jets were in t he direction of rotation in one channel and opposite to the rotation d irection in the other channel. The jets impinged normally on the smoot h, 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 varie d from 0.0 to 0.0028 and 5000 to 10 000, respectively. For the target walls with jet flow in the direction of rotation (or opposite to the d irection of rotation), heat transfer decreased up to 15% (or 20%) as c ompared to corresponding results for non-rotating conditions. This is because the impinging jets were affected by the rotation-inducted seco ndary flows produced by Coriolis, buoyancy and centrifugal forces. (C) 1998 Elsevier Science Ltd. All rights reserved.