1998 Fiscal Year Final Research Report Summary
An Experimental Study on Flow Control with Longitudinal Vortices and Enhancement of Target Plate Heat Transfer
| Project/Area Number |
09650238
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
NAKABE Kazuyoshi Dept.of Mechanical Engineering, KYOTO UNIVERSITY Associate Professor, 工学研究科, 助教授 (80164268)
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| Co-Investigator(Kenkyū-buntansha) |
INAOKA Kyoji Dept.of Mechanical Engineering, KYOTO UNIVERSITY Lecturer, 工学研究科, 講師 (60243052)
SUZUKI Kenjiro Dept.of Mechanical Engineering, KYOTO UNIVERSITY Professor, 工学研究科, 教授 (00026064)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Longitudinal Vortices / Inclined Impinging Jet / Heat Transfer / Thermochromic Liquid Crystal / Laser Optical Measurement |
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| Research Abstract |
One of the most fundamental principles to improve the energy conversion efficiency is to raise the working temperature of a gas turbine. in order to realize high temperature gas turbine, development of effective cooling system of turbine blades and vanes is indispensable. The attention was paid to the utilization of longitudinal vortices to enhance the local heat transfer from the inner surfaces of turbine vanes, In this study, flow velocity measurements and heat transfer experiments were carried out for a jet obliquely discharged into a crossflow in a duct. The direction of the jet is characterized by the following two angles ; one is a pitch angle raised from the surface of the jet-installed plate, and the other a skew angle measured between the directions of the crossflow and the impinging jet projected onto the jet-installed plate. Two-component flow measurements were made with two-dimensinal optical fiber laser Doppler velocimetry, and the heat transfer experiments were made by making use of a thermochromic liquid crystal. A hierarchy neural network system was applied to convert color images of the liquid crystal into temperature distributions. The obtained velocity data reveal that the inclined jet is effective in generating a pair of counter-rotating longitudinal vortices in the crossflow. The heat transfer enhancement areas correspond well to the distributions of the time-averaged velocity vectors and their turbulent fluctuations. It is demonstrated that the longitudinal vortices are effective in enhancing target plate jet impingement heat transfer. It is, therefore, promising as a means to effectively cool inner surfaces of high temperature gas turbine vanes.
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