Innovative Turbine Stator Well Design Using a Kriging-Assisted Optimization Method

Abstract

At present, it is a common practice to expose engine components to main annulus air temperatures exceeding the thermal material limit in order to increase the overall engine performance and to minimize the engine specific fuel consumption. To prevent overheating of the materials and thus the reduction of component life, an internal flow system is required to cool and protect the critical engine parts. Previous studies have shown that the insertion of a deflector plate in turbine cavities leads to a more effective use of reduced cooling air, since the coolant is fed more effectively into the disk boundary layer. This paper describes a flexible design parameterization of an engine representative turbine stator well geometry with stationary deflector plate and its implementation within an automated design optimization process using automatic meshing and steady-state computational fluid dynamics (CFD). Special attention and effort is turned to the flexibility of the parameterization method in order to reduce the number of design variables to a minimum on the one hand, but increasing the design space flexibility and generality on the other. Finally, the optimized design is evaluated using a previously validated conjugate heat transfer method (by coupling a finite element analysis (FEA) to CFD) and compared against both the nonoptimized deflector design and a reference baseline design without a deflector plate.

Sequential Design Process for Screening and Optimization of Robustness and Reliability Based on Finite Element Analysis and Meta-Modeling

“…In practice, the complexity and the computational expense of simulations (here based on finite element analysis) typically prevent direct optimization, and meta-models are therefore required. Latin Hypercube Sampling combined with Kriging is often preferred to generate accurate meta-models for non-linear systems [14]. However, evaluating multiple design concepts and load cases becomes computationally expensive by adopting such approaches.…”

Windage Torque Reduction in Low-Pressure Turbine Cavities Part II: Experimental and Numerical Results

“…Combined experimental and computational heat transfer studies have been performed to understand the thermomechanical behaviour of stator-well cavities [9]. Computations demonstrate that the heat transfer can be enhanced with an angled plate adjacent to the entrance of the cooling flow into the cavity [10]. The geometry of the plate was optimised to direct the flow into the rotor boundary layer.…”