Effects of Gas Thermophysical Properties on the Full-Range Endwall Film Cooling of a Turbine Vane

• Published in: Aerospace Vol. 10; no. 7; p. 592
• Main Authors: Liu, Jian, Xu, Mengyao, Xi, Wenxiong
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.07.2023
• Subjects: Analysis; Compressed air; coolant coverage; Coolants; Cooling; Density ratio; Design; Efficiency; endwall film cooling; Exhaust gases; Film cooling; Fluid flow; Gas flow; Gas turbines; Heat; Heat transfer; Heat transfer coefficients; Horseshoe vortices; Ideal gas; Injection; Modelling; Numerical analysis; Real gases; Reynolds number; Streamlines; Thermophysical models; Thermophysical properties; thermophysical property; turbine vane; Turbines; Turbulence models; Variance analysis; Vortices; Working conditions
• ISSN: 2226-4310; 2226-4310
• DOI: 10.3390/aerospace10070592

To protect turbine endwall from heat damage of hot exhaust gas, film cooling is the most significant method. The complex vortex structures on the endwall, such as the development of horseshoe vortices and transverse flow, affects cooling coverage on the endwall. In this study, the effects of gas thermophysical properties on full-range endwall film cooling of a turbine vane are investigated. Three kinds of gas thermophysical properties models are considered, i.e., the constant property gas model, ideal gas model, and real gas model, with six full-range endwall film cooling holes patterns based on different distribution principles. From the results, when gas thermophysical properties are considered, the coolant coverage in the pressure side (PS)-vane junction region is improved in Pattern B, Pattern D, Pattern E, and Pattern F, which are respectively designed based on the passage middle gap, limiting streamlines, heat transfer coefficients (HTCs), and four-holes pattern. Endwall η distribution is mainly determined by relative ratio of ejecting velocity and density of the hot gas and the coolant. For the cooling holes on the endwall with an injection angle of 30°, the density ratio is more dominant in determining the coolant coverage. At the injection angle of 45°, i.e., the slot region, the ejecting velocity is more dominant in determining the coolant coverage. When the ejecting velocity Is large enough from the slot, the coolant coverage on the downstream endwall region is also improved.