Session: 15-05 Rotating Heat Transfer 2

Paper Number: 82035

82035 - Heat Transfer in a Rotating, Blade-Shaped, Two-Pass Cooling Channel With Various 45 Deg Rib Turbulators and a Tip Turning Vane 

This study features a rotating, blade-shaped, two-pass cooling channel with various 45 deg rib turbulators and a tip turning vane. The heat transfer and pressure loss were experimentally studied in a serpentine cooling channel with two 45 deg rib orientations and a tip turning vane. The first passage of the cooling channel has an aspect ratio (AR) = 4:1 with the coolant moving radially outward. After a 180 deg blade-shaped tip turn, the coolant flows radially inward into the second passage with an AR = 2:1. The first and second passages are oriented at 50 deg and 105 deg from the rotation direction, respectively. In the tip turn portion, a tip turning vane with an oval cross section connects the mid-lines of the two passes. Two orientations of 45 deg angled ribs were considered in this work: unusual, and criss-cross. The ribs have a profiled cross section and were placed in-line (P/e = 10, e/H= 0.16) on the leading and trailing surfaces of the channel. Five inlet Reynolds numbers (10,000 to 45,000) and five rotational speeds (0-400 rpm) were considered in this study, with a maximum rotation number of Ro = 0.38 achieved in the first pass. The results showed that the turning vane decreases both heat transfer and pressure loss in the serpentine channel. The reduction on heat transfer and pressure loss in the 45 deg unusual rib case was the lowest among the cases. For pressure loss, the turning vane provided approximately 8% reduction in the 45 deg criss-cross ribbed case, which was the highest in the rib cases. With a high reduction in pressure loss and only a moderate heat transfer decrease, the 45 deg criss-cross ribs presented the highest thermal performance with the turning vane.

Presenting Author: I-Lun Chen Texas A&M University

Presenting Author Biography: Research assistant in the Turbine Heat Transfer Laboratory at Texas A&amp;M University.<br/>Research interests: Fluid mechanics, Computational methods (CFD), Energy, Heat transfer, Turbomachinery

Authors:

I-Lun Chen Texas A&M University
Lesley M. Wright Texas A&M University
Je-Chin Han Texas A&M University
Robert Krewinkel MAN Energy Solutions SE