Abstract

not-yet-known not-yet-known not-yet-known unknown In order to alleviate computational duties of MDO (Multidisciplinary Design Optimization) or RA (Reliability Analysis) involving multi-blade interaction in aeroengine design, an interface ROM (reduced order model) method is proposed to replace upstream and/or downstream domains in CFD (Computational Fluid Dynamics) simulations, in which flow passage is divided into upstream, midstream, and downstream and midstream blade is under design. In the method, the interface velocity and pressure relations between upstream and midstream and those between downstream and midstream are identified by Volterra series firstly, which are called ROM here. Then, the ROMs are coded into user defined function (UDF) and imposed on the inlet and outlet of the midstream CFD model to characterize the influence of upstream and downstream. In this way, the multi-blade CFD simulation is transformed into a simple simulation of the midstream blade, while the effect of multi-blade interaction is kept. This will greatly reduce CFD costs involving multiple blades. The paper addresses two primary issues of the method: 1) how to build interface ROM by Volterra series; 2) how to consider the working condition change in the ROM. A flow passage example of three blades is used to verify the proposed method. The results indicate that the proposed method is feasible. The results also show that there is error in the ROM method. The error is minimal when only one of the upstream and downstream domains is replaced by ROM. It increases when both upstream and downstream domains are replaced by ROM.