Experimental heat transfer measurement technique validation and measurements in a linear cascade of an OGV and endwall

Abstract

The scope of this Master thesis is to study the heat transfer on the endwall of an OGV located in a low speed linear cascade facility. Prior to performing these experiments, the instrumented endwall for heat transfer measurements was validated. Two experiments are carried out for this purpose. At first, a steady impinging jet over the instrumented endwall is studied while in the second experiment a flat plate case is studied. After the validation of the endwall the tests are performed in the linear cascade to evaluate the heat transfer coefficient of the OGV. The heat transfer study performed on the endwall can help to understand better the complex heat transfer mechanisms involved in this case, and hence, the information can be used for CFD validation purposes. The OGVs are located downstream of the last stage of a low pressure turbine (LPT) where the exhaust gases are at high temperatures. Therefore, understanding of flow characteristics and heat transfer distribution in this hot structure has been of great interest of several research groups. Hence, the main goal of this thesis is to obtain the heat transfer coefficient on the endwall of a low-speed OGV linear cascade for CFD validation and produce data to compare it with previous experiments. The results of the heat transfer for the different configuration of the endwall and vanes are discussed in this thesis.