Session: 15-07 Numerical Studies of Internal Cooling

Paper Number: 124526

124526 - Flow and Heat Transfer in a Ribbed Converging-Diverging U-Duct Under Rotating and Non-Rotating Conditions 

A numerical study based on steady RANS with the SST turbulence model was performed to investigate the flow and heat transfer in a ribbed U-duct with a rectangular cross section that converges linearly in the radially outward direction and diverges linearly in the radially inward direction under rotating and non-rotating conditions. Parameters studied include rotation number (Ro = 0, 0.022, 0.034, 0.073), Reynolds number (Re = 46,000, 100,000, and 154,000), and rate of change of the cross-sectional area (inclination angle = 0° and 1.41°), where the ratio of the temperature of the cooling air to the wall temperature at the U-duct’s inlet was kept at 0.57.  Results are presented that show the nature of the flow and how the flow affects the friction coefficient, heat flux, and Nusselt number as a function of the parameters studied.  Results obtained show increasing the inclination angle from 0° to 1.41° to significantly increase the friction coefficient and the Nusselt number whether there is rotation or not. The maximum increase in the average friction coefficient and Nusselt number was found to be 52.8% and 14.8%[JK1]  respectively when Re = 46,000 and Ro = 0 and 96.3% and 36.6% respectively when Re = 100,000 and Ro = 0.034.

Presenting Author: Wanjae Kim Purdue University

Presenting Author Biography: Wanjae Kim: MS, KAIST. Currently, PhD student, School of Aeronautics and Astronautics, Purdue University.
Previously, Senior Researcher, KEPCO.

Authors:

Wanjae Kim Purdue University
Tom Shih Purdue University
Kenneth Bryden Iowa State University
Richard Dalton National Energy Technology Laboratory
Sung Yong Chang Korea Electric Power Research Institute
Gyu Sang Park Korea Electric Power Research Institute