An Experimental Study on Flow Control with Longitudinal Vortices and Enhancement of Target Plate Heat Transfer

纵向涡流控制及强化靶板传热的实验研究

基本信息

批准号：
09650238
负责人：
NAKABE Kazuyoshi
金额：
$ 2.05万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

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.

提高能源转化效率的最基本原理之一是提高燃气轮机的工作温度。为了实现高温燃气轮机，必不可少的涡轮叶片和叶片的有效冷却系统是必不可少的。注意纵向涡流的利用来增强涡轮叶片内表面的局部热传递，在这项研究中，进行流速测量和热传递实验，以斜干地排入管道中的交叉流中。射流的方向以以下两个角度为特征。一个是从射流安装的板的表面凸起的俯仰角，另一个是在交叉流的方向和投射到喷射式安装板上的撞击射流之间测量的偏斜角。用两二维光纤激光多普勒多普勒速度法进行了两组分量测量，并通过使用热颗粒液体晶体进行传热实验。应用层次结构神经网络系统将液晶的颜色图像转换为温度分布。获得的速度数据表明，倾斜射流可以有效地在横流中产生一对反旋转纵向涡旋。传热增强区域与时间平均速度向量及其湍流波动的分布很好。证明纵向涡流有效增强目标板射流撞击传热。因此，它是有效冷却高温燃气轮机叶片内表面的一种方法。