Enhanced Gas Turbine Performance Simulation Using CFD Modules in a 2D Representation of the Low-Pressure System for a High Bypass Turbofan

The improvement of performance simulation for gas turbines has been approached in very different ways. In particular for high bypass turbofans, efforts have been made to investigate radial flow distributions. The aim of the presented study was to combine a conventional characteristics based performance code using a 2d representation of the fan with 2d representations of the adjoining intake and bypass system. Computational Fluid Dynamics was the chosen tool to generate modules for the intake, bypass duct and bypass nozzle. This approach required geometry data. A design procedure to generate these components in an axi-symmetric meridional fashion and the numerical requirements for the CFD modules were developed. Typical component performances were predicted and the combined use of CFD and the performance code showed that in terms of performance, the inclusion of intake and bypass losses and the radial inlet distribution was worth considering. In particular however, the required numerical effort was significant.