Optimization of tip seal with honeycomb land in LP counter rotating gas turbine engine

The goal of the presented work is an optimization of the geometrical configuration of the tip seal with a honeycomb land, to reduce the leakage flow in the counter-rotating LP turbine of a contra-rotating open rotor aero-engine. This goal was achieved with the use of the Ansys-CFX commercial code and an in-house optimization procedure. The detailed studies including the mesh influence, the stages of the computational domain simplification, and geometry variants are discussed. The optimization process is based on a single objective genetic algorithm (SOGA). The automatic grid generation process and the CFD calculations are based on scripts prepared under the Ansys-ICEM and Ansys-CFX software. The whole procedure is written in the Visual Basic for Applications language (VBA), which allows a direct access to the CAD software with the use of macros and allows a proper connection between the CAD environment and the CFD software. The described algorithm allows parallel computing. In addition to the optimization studies, a sensitivity analysis was also performed. For this purpose, the Elementary Effects Method (EEM) was used. This paper was written within the DREAM European project (Validation of Radical Engine Architecture Systems) of the 7th Framework Program of the European Union.