Analysis of Combustor/Vane Interaction with Decoupled and Loosely Coupled Approaches

Numerical techniques are commonly used during both design and analysis processes, mainly considering separated components. Technological progress asks for advanced approaches that allow to analysing the interaction between the components, especially when considering combustor/turbine interaction. Hot spots and inlet swirl profiles generated by the combustor have been demonstrated to affect high-pressure turbine performances and reliability. This work deals with the investigation of the effects of realistic boundary conditions for the high-pressure turbine vane, also proposing an approach for coupled simulation of the combustor/vane interaction. The method consists in a loosely coupled approach for the data exchange on the combustor/vane interface section. Data from the combustor exit section (stagnation conditions, velocity profile and turbulent quantities) are provided to the vane inlet and vice versa (for the static pressure). The proposed method is applied to a test case consisting of a redesigned combustor and the vane of the MT1 test case from QinetiQ. A preliminary analysis was dedicated to define the combustor geometry and the operating conditions. Then, the MT1 working conditions have been rescaled and coupled with the combustor, maintaining the stage geometry and the experimental non-dimensional parameters. Second order accurate steady simulations were performed for both combustor and high-pressure turbine vane. Calculations with a uniform profile and a theoretical nonuniform inlet profile (deriving from the EU funded TATEF2 project) have been considered as representative of commonly used approaches. The results obtained for the stator in terms of isentropic Mach number and Nusselt number along blades surfaces and inner end-wall are compared with each other and with the available experimental data. Due to the large dimension of computational grids a parallel approach was applied. The activity was carried out using the IBM PLX supercomputer in the frame of the FrUIT project supported by CINECA.