Strong aerodynamic coupling can make the high fidelity simulation of a number of critical aero-engine components prohibitively expensive — particularly within the timeframes of industrial design cycles. This paper develops a body force based hierarchy of approaches to modelling the effects of blade rows. These are envisaged as allowing the computationally expensive parts of coupled systems to be resolved much more cheaply, rendering the cost of the overall simulation as more manageable. Simulation of the coupling that exists between the flow around an aero-engine intake and its fan is particularly emphasised, as this is becoming stronger and more performance critical with the modern trends towards the reduction of the relative diffuser length.
The use of the viscous smeared geometry level of fidelity is initially shown to be an effective model over a number of cases — a simple compressor blade row, a modern high bypass fan, and the Darmstadt rotor. After this, it is shown working as part of a coupled system in an intake experiencing cross-flow. Higher fidelity geometry representations are then considered, which mimic the effect of struts. Finally, a mix of various fidelity geometry representations and turbulence modelling approaches is shown to bring otherwise hugely expensive calculations within the realm of practical computation, in the form of a full fan-to-flap calculation.