Towards a Fully Coupled Component Zooming Approach in Engine Performance Simulation

This paper presents a fully-coupled zooming approach for the performance simulation of modern very high bypass ratio turbofan engines developed by Snecma. This simulation is achieved by merging detailed 3D simulations and map component models into a unified representation of the whole engine. Today’s state-of-the-art engine cycle analysis are commonly based on component mapping models which enable component interactions to be considered, while CFD simulations are carried out separately and therefore overlook those interactions. With the methodology discussed in this paper, the detailed analysis of an engine component is no longer considered apart, but directly within the whole engine performance model. Moreover, all links between the 3D simulation and overall engine models have been automated making this zooming simulation fully-integrated. The simulation uses the PROOSIS propulsion object-oriented simulation software developed by Empresarios Agrupados for whole engine cycle analysis and the computational fluid dynamics (CFD) code CEDRE developed by ONERA for the high fidelity 3-D component simulations. The whole engine model is created by linking component models through their communication ports in a graphical user-friendly interface. CFD simulated component models have been implemented in PROOSIS libraries already providing mapped components. Simple averaging techniques have been developed to handle 3D-to-0D data exchange. Boundary conditions of the whole engine model remain the same as for the typical 0-D engine cycle analysis while those of the 3-D simulations are automatically given by PROOSIS to CEDRE. This methodology has been applied on an advanced very high bypass ratio engine developed by Price Induction. The proposed zooming approach has been performed on the fan stage when simulating Main Design Point as well as severe case of off-design conditions such as wind-milling. The results have been achieved within the same time frame of a typical CFD fully-converged calculation. A detailed comparison with upcoming test results will provide a first validation of the methodology and will be presented in a future paper.