EFFECT OF MODEL ORIENTATION AND WALL HEATING CONDITION ON LOCAL HEAT-TRANSFER IN A ROTATING 2-PASS SQUARE CHANNEL WITH RIB TURBULATORS

The influences of channel orientation and wall heating condition on th e local surface heat transfer coefficient in a rotating, two-pass, squ are channel with 60 degrees and 90 degrees ribs on the leading and tra iling walls were investigated for Reynolds numbers from 2500 to 25000 and rotation numbers from 0 to 0.352. The two channel orientations wer e (1) square channel perpendicular to the axis of rotation and (2) squ are channel twisted at 45 degrees to the axis of rotation. Two thermal boundary condition cases were studied: (A) all four walls at the same temperature and (B) all four walls at the same heat flux. Results sho w the Coriolis force effect is reduced for the 45 degrees channel orie ntation. Thus, heat transfer coefficients decrease for the first pass trailing and second pass leading walls and increase for the first pass leading and second pass trailing walls, compared with their correspon ding perpendicular channel orientation values. The increase of heat tr ansfer coefficients for uneven wall heating condition Case (B) when co mpared to their corresponding heat transfer coefficients for Case A is greater for the 45 degrees channel orientation than for the perpendic ular channel orientation.