Adiabatic and conjugate simulations on the flow field in a gas turbine vane with pressure side film cooling and trailing edge cutback

Abstract

The present study concentrates on the numerical investigation of pressure side film cooling in a linear nozzle vane cascade typical of a high-pressure turbine in gas turbine engines. The cooling scheme features a pressure side cutback and two rows of cooling holes located upstream of the cutback. The main goal is to evaluate the applicability of a simple numerical method, i.e. the steady incompressible Reynolds-averaged Navier Stokes, in such a complex industrial application. The simulations are performed according to an adiabatic and conjugate approach. Two values of the coolant-to-mainstream mass flow ratio ( MFR = 1% and 2.8%) are simulated at exit Mach number of M2 is = 0.2. The computed flow/temperature fields in the cooled regions of the vane pressure side are presented and compared to available measurements of: holes and cutback exit velocity and discharge behavior; boundary layer along traverses at strategic axial locations, adiabatic film cooling effectiveness. In addition, distributions of overall film cooling effectiveness and heat transfer coefficients are reported for the conjugate cases. Both adiabatic and conjugate techniques provide reasonable predictions of three-dimensional aerodynamic and thermal features of the investigated cooled vane. The conjugate heat transfer is much more complicated than one-dimensional conduction within the vane material.