Rotary machine – turbines, fans, pumps, propellers etc – are inherently complex machines that lend themselves to design optimisation through CFD.  Design insight can be gained through careful CFD modelling. In particularly sensitive systems like jet engine design, incorporating Fluid-Structure Interaction (FSI), whereby the coupled behaviour of fluid flow’s influence on the structural behaviour of the machine (its shape deformation under load), and the reciprocal influence of the structure on the fluid behaviour, can significantly improve the simulation accuracy.  CFD can thus be used to optimise the machine’s performance.