Abstract

In aircraft engines, one of the main goals is to decrease fuel consumption while minimizing design time and cost. The attachment between the blade and disc is a critical region of the turbine as it is subjected to high stress due to centrifugal and thermal loads that are transferred between these two components. Failure of this region can lead to critical engine failure. In this paper, a design optimization framework of the turbine blade and disc attachment, called fixing, is presented. The objective function of the optimization is to minimize the weight of the fixing while ensuring that stresses are in safe limits to avoid mechanical failure. For the optimization, in-house tools of Pratt & Whitney Canada will be used. Firstly, a Design and Analysis (D&A) tool will be used that combines Computer Aided Design (CAD) and Finite Element Analysis (FEA) commercial software running in batch mode. Furthermore, a Surrogate Assisted Optimization (SAO) tool will be used to explore the design space and find the optimum design. An in-house code has also been created that links the D&A and SAO tools. After the optimization framework was set up, a Design of Experiment (DOE) was used to create a sample of fixing configurations and a sensitivity analysis was implemented based on this sample. The results of the sensitivity analysis showed which geometric parameters have the greatest impact on the stresses applied on a fixing. Only the sensitive parameters were chosen to be optimized. The goal of this paper is to create an automated optimization tool that will increase the accuracy and decrease the time of the pre- detailed design process.

Keywords

gas turbine, fuel consumption, optimization framework, aerodynamics, aircraft engines, blade, computational cost