Influence of Gap Leakage on the Film Effectiveness and Heat Transfer Around Discrete Injection Holes
Author : Yue Cheng Hsing
Publisher :
ISBN 13 :
Total Pages : 166 pages
Book Rating : 4.:/5 (59 download)
Book Synopsis Influence of Gap Leakage on the Film Effectiveness and Heat Transfer Around Discrete Injection Holes by : Yue Cheng Hsing
Download or read book Influence of Gap Leakage on the Film Effectiveness and Heat Transfer Around Discrete Injection Holes written by Yue Cheng Hsing and published by . This book was released on 1997 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research has been performed to investigate the heat transfer characteristics of cooling film over a misaligned leaking gap, using a thermographic phosphor fluorescence imaging technique. Such a flow pattern is usually seen on the component-to-component interface of inlet guide vanes in a gas turbine system. This problem can be classified as a four-temperature problem. The present study defines a true driving potential of the convective heat transfer of a four-temperature system. Experiments are performed systematically to investigate problems of traditional film cooling, the gap leakage together with a misaligned interface effect, and finally, a combined four-temperature system. The result of current film cooling studies reveals a comparable agreement with that found in open literature using conventional measurement techniques. The same conclusion is obtained for a gap leakage study at an aligned interface circumstance. Another finding of the gap leakage study is that the cooling performance in a backward-facing step is the best among all misaligned interface situations. For a four-temperature situation, the flowfield changes significantly in the presence of a leaking gap downstream of film-cooling jets or vise versa. The cooling performance of each coolant injection is either enhanced or degraded, depending on the ratio of the blow strength the first coolant film to that of the second. The misaligned interface effect lessens when the ratio is smaller than one. In contrast to the gap leakage results, the forward-facing step situation presents the best film effectiveness distribution. Generally, the cooling performance is decreased when film-cooling jets re revealed upstream of a gap leakage. The effect is opposite when a leaking gap is located upstream.
