Aerodynamic Optimization of High-Pressure Turbines for Lean-Burn Combustion System

Abstract

Modern lean-burn combustors make use of high flow swirl to maintain flame stability. The swirling flow can persist downstream of the turbine first vane, changing the loading on the rotor, leading to a reduction in efficiency. This paper presents the results of an automatic optimization study carried out to mitigate the effect of high swirling flow on a high pressure turbine stage. A high-fidelity computational fluid dynamics (CFD)-based design optimization using a multipoint approximation (response surface) method is carried out to produce a new vane and a new rotor configuration with a significantly improved aerodynamic performance. It is demonstrated that the novel optimization methodology can cope well with a number of near equality constraints needed for a practical design.