Numerical research of a new vortex double wall cooling configuration for gas turbine blade leading edge

In order to explore new cooling methods to further improve the cooling performance for the gas turbine blade leading edge, a vortex double wall cooling configuration is established and studied. The numerical simulation was conducted after grid independence validation and turbulence model validation. Four groups of different combined cooling methods, different disturbing objects, different rows of bridge holes and the existence of film holes were studied in detail. Results showed that the vortex double wall cooling method could improve the cooling performance by more than 3 times than the basic straight passage double wall cooling. And compared to impingement double wall cooling, the vortex double wall cooling has better cooling behavior with larger inner surface Nusselt number and globally-averaged Nusselt number. Different disturbing objects on the outer surface could improve the local heat transfer performance without affecting the overall cooling performance, and protrusions are found to be a good kind of disturbing objects. When rows of bridge holes increase to 3, its thermal performance factor is 23.6% higher than case with 1 bridge hole row. It is regarded that increasing bridge hole rows could bring considerable cooling improvements. For the condition with film holes, it is found the overall flow and heat transfer performance is 6.2% higher than case without film holes. Generally, the vortex double wall cooling method proves to be a potential cooling method for the leading edge, and the configuration with protrusions and more rows of bridge holes could further improve its cooling behavior.