Session: 13-05 External and Internal Flow Heat Transfer II

Paper Number: 83477

83477 - The Influence of Turbulence and Reynolds Number on Endwall Heat Transfer in a Vane Cascade 

Endwall heat transfer measurements have been acquired in a vane cascade over a range of turbulence conditions and Reynolds numbers using an array of small commercial IR cameras.  The linear cascade was tested over five inlet turbulence conditions ranging from low turbulence (0.7%) to high turbulence (17.4%) and three exit chord Reynolds numbers ranging from 500,000 to 2,000,000.  The small commercial IR cameras made by Therm-App had a resolution of 384 by 288 pixels and were connected to individual smart phones to record the images.  The cascade was modified with small zinc selenide windows  to provide IR access for the cameras.  Prior to using the cameras to acquire endwall heat transfer measurements they were calibrated against a constant temperature test plate adjusting the images for thermal droop and the fisheye effect.  The large-scale low-speed cascade was configured in a four vane three full passage arrangement.  The vane design includes a large leading and aft loading.  This same cascade has been used in the acquisition of vane surface heat transfer distributions, vane suction surface heat transfer visualizations, and vane surface film cooling distributions.  This paper includes comparisons with two LES calculations, which were conducted prior to the acquisition of the heat transfer data.  The influence of the secondary flows including the leading edge horseshoe vortex system are particularly visible at lower turbulence levels and lower Reynolds numbers.  However, at higher turbulence levels the influence of secondary flows are less visible but the influence of Reynolds number and turbulence on transition can be discerned.

Presenting Author: Forrest Ames Univ Of North Dakota

Presenting Author Biography: Forrest Ames is a Professor at the University of North Dakota (UND) in the Mechanical Engineering Department. He has been a member of UND's faculty since 1997. Prior to his position at UND he worked at Allison Gas Turbine Division of General Motors/Rolls Royce.

Authors:

Forrest Ames Univ Of North Dakota
Emmanuel Chukwuemeka University of North Dakota
Maliha Yel Mahi University of North Dakota
Yousef Kanani Illinois Institute of Technology
Sumanta Acharya Illinois Institute of Technology
Shaun Donovan University of North Dakota