Advanced Numerical Modeling and Simulation of Secondary Air Systems

摘要

This paper presents four examples of advanced CFD and CHT analyses applied to gas turbine secondary air system. The first example is an anti-vortex device designed to feed cooling air to the turbines of a turboprop. It also serves as a demonstration how alternative approaches to mesh generation can provide accurate solutions when friction losses are not the main driver for the pressure drop. The second example deals with the impeller rear cavity of a turboprop engine. Here, the two-equation turbulence model is calibrated to provide accurate pressure and velocity fields. The third case details the flow and thermal analysis of a pre-cooler located in the bypass of a small turbofan engine. It is demonstrated that the solution fields may be affected by the time derivative implemented in the solver, requiring that the analyst adapt his post-processing strategy to avoid adding unacceptable noise in the results. The last of these examples details the automated optimization of a bleed-off valve, relying entirely on commercial CAD and CFD tools for greater flexibility.