Session: 15-09 Impingement and Internal Cooling

Paper Number: 127420

127420 - Effects of the Shape Modification of the Leading Edge Impingement Cooling for Turbine Blade 

 Turbine inlet gas temperature (TIT) has been becoming higher and higher to improve an efficiency of the gas turbines with less cooling air consumption. Therefore, a new promising cooling structure is required. 
 In impingement cooling, it is important to consider eliminating the influence of crossflow in order to improve heat transfer coefficient. Therefore, in this work, the effects of shape modification on the leading edge impingement cooling for the turbine blade with crossflow conditions have been investigated numerically and experimentally.
The heat transfer coefficient on the cooling side of the leading edge was calculated using CFD(RANS) in a static system. The CFD model was created using a shape that resembles a partial cut of the midspan position of the turbine blade leading edge, incorporating impingement cooling and film cooling, and impingement hole pitches, hole shapes, and variations in the impingement target surface shape were changed. Based on the effective heat transfer coefficient considering the area of impingement target surface, two specific configurations were selected for the rig test specimen.
 In the experiment, the shape of test-piece was same to the CFD model, and the cooling structures selected through CFD was applied to them. The mainstream temperature and pressure were adjusted to achieve a Reynolds number equivalent to the actual operating conditions. And the cooling air for impingement and crossflow can be supplied separately. The impingement Reynolds number was varied from 5.0×10³ to 3.5×10⁴. Furthermore, to investigate of the effect of crossflow, the flow rate was also varied at half, double, and zero flow rates compared to the base value.
 The surface temperature of the specimen was obtained using Infrared thermal cameras calibrated thermos couple on the surface, and the measured temperatures were then converted into cooling effectiveness. 
 In this paper, we show the result and discuss about it.

Presenting Author: Kozo Nita IHI Corporation

Presenting Author Biography: Nita, graduated from Tokyo University (Faculty of Engineering). He then joined the Research and Engineering Division of IHI Corporation as a researcher. Now, an assistant manager of Combustion and Cooling Technology Group, Aero Engine,Space and Defence Business Area, IHI. Main interest and expertise in cooling design, advanced heat transfer augmentation technologies, and innovative film cooling methods for aero-engine turbine blades / vanes.

Authors:

Kozo Nita IHI Corporation
Shu Fujimoto IHI Corporation
Masaya Suzuki Japan Aerospace Exploration Agency
Junichi Kazawa Japan Aerospace Exploration Agency
Yoji Okita Japan Aerospace Exploration Agency