Rotation Effect on Jet Impingement Heat Transfer in Smooth Rectangular Channels with Film Coolant Extraction

James A Parsons,Je-Chin Han

doi:10.1155/s1023621x01000082

Abstract

The effect of channel rotation on jet impingement cooling by arrays of circular jets in twin channels was studied. Impinging jet flows were in the direction of rotation in one channel and opposite to the direction of rotation in the other channel. The jets impinged normally on the smooth, heated target wall in each channel. The spent air exited the channels through extraction holes in each target wall, which eliminates cross flow on other jets. Jet rotation numbers and jet Reynolds numbers varied from 0.0 to 0.0028 and 5000 to 10,000, respectively. For the target walls with jet flow in the direction of rotation (or opposite to the direction of rotation), as rotation number increases heat transfer decreases up to 25% (or 15%) as compared to corresponding results for non-rotating conditions. This is due to the changes in flow distribution and rotation induced Coriolis and centrifugal forces.

Highlights

Several methods such as film cooling, augmented cooling in internal serpentine channels and impingement cooling on internal surfaces are in use to cool turbine blades
The goal of this investigation is to extend the understanding of internal jet impingement cooling in channels for film-cooled turbine blades under
Parsons et al (1998) heated all four channel walls with cross flow and rotation, and found that the target wall and jet wall heat transfer coefficients decrease up to 20% with respect to those without rotation

Summary

Introduction

Several methods such as film cooling, augmented cooling in internal serpentine channels and impingement cooling on internal surfaces are in use to cool turbine blades. Durability goals require these cooling methods for rotor blades of advanced gas turbine engines. Since any amount of coolant (air extracted from the compressor) penalizes engine performance, it is necessary to understand and to optimize turbine coiling method employed, and the turbine blade geometry. Turbine blade heat transfer characteristics under rotating conditions are different from those for non-rotation. The goal of this investigation is to extend the understanding of internal jet impingement cooling in channels for film-cooled turbine blades under

Methods

Results

Conclusion