DETAILED HEAT-TRANSFER DISTRIBUTIONS IN 2-PASS SQUARE CHANNELS WITH RIB TURBULATORS

Detailed Nusselt number distributions are presented for a two-pass squ are channel with one ribbed wall. This wall of the channel is sprayed with thermochromic liquid crystals, and a transient test is run to obt ain the local beat transfer coeffcients. Results are presented for Rey nolds numbers ranging from 6000 to 60 000. The rib height-to-hydraulic diameter ratio is 0.125; the rib pitch-to-height ratio is 10; and the rib configurations are 90 degrees parallel, 60 degrees parallel, 60 d egrees V, and 60 degrees broken V. Detailed measurements are presented in the first pass, before the 180 degrees turn, in the turn region, a fter the turn, and further downstream in the second pass. The detailed distributions provide a clear understanding of the secondary flows in duced by the 180 degrees turn and the rib turbulators. (C) 1997 Elsevi er Science Ltd.