استاندارد و انتقال تنش برشي K-4 شبيه سازي عددي خنك كاري لايه يي جريان آشفته با استفاده از مدل هاي آشفتگي

NUMERICAL SIMULATION OF A TURBULENT FILM COOLING FLOW USING STANDARD "k-e" AND "SHEAR STRESS TRANSPORT" MODELS

Film cooling has many applications such as in gas turbine blades. To increase the efficiency of gas turbines, the temperature of the gas entering the turbine needs to be high. However, the blades have structural limitations and need to be somehow cooled. Film cooling holes are usually installed on the bladeʹs surface, such that, the cooler air makes a film of cooling resistant for the blades. In this work, three-dimensional numerical film cooling of turbulent flow over a portion of a blade (flat plate assumption) is investigated. The flow inside the channel of the hole, along with the flow over the plate, is considered. For turbulent modeling, a k-E standard model plus a shear stress transport (SST) model are used. For a 90° jet, the results of this research are compared with existing experimental benchmark data and are in relatively good agreements. Also, by comparing the film cooling effectiveness (7) for different speed ratios and different jet angles, their optimum values are obtained.