BEM/FDM conjugate heat transfer analysis of a two-dimensional air-cooled turbine blade boundary layer

Abstract

A coupled boundary element method (BEM) and finite difference method (FDM) are applied to solve conjugate heat transfer problem of a two-dimensional air-cooled turbine blade boundary layer. A loosely coupled strategy is adopted, in which each set of field equations is solved to provide boundary conditions for the other. The Navier-Stokes equations are solved by HIT-NS code. In this code, the FDM is adopted and is used to resolve the convective heat transfer in the fluid region. The BEM code is used to resolve the conduction heat transfer in the solid region. An iterated convergence criterion is the continuity of temperature and heat flux at the fluid-solid interface. The numerical results from the BEM adopted in this paper are in good agreement with the results of analytical solution and the results of commercial code, such as Fluent 6.2. The BEM avoids the complicated mesh needed in other computation method and saves the computation time. The results prove that the BEM adopted in this paper can give the same precision in numerical results with less boundary points. Comparing the conjugate results with the numerical results of an adiabatic wall flow solution, it reveals a significant difference in the distribution of metal temperatures. The results from conjugate heat transfer analysis are more accurate and they are closer to realistic thermal environment of turbines.

Modelling of heat transfer and fluid flow in the hot section of gas turbines used in power generation: A comprehensive survey

“…To calculate the blade temperatures accurately, conditions of external hot gases, metal conduction, and internal coolant should be calculated simultaneously (using the conjugate heat transfer method) . Bohn et al, Luo et al, Ledezma et al, and Wang et al performed the heat transfer modelling on C3X and Mark‐II vane profiles in a single solver. The C3X vane profile has an arrangement of 10 cooling holes and a circular trailing edge.…”