Modelling the dynamics of ring plate valves in reciprocating compressors using coupled CFD-FEM simulations

Improving the efficiency and reliability of valves in the reciprocating compressor is important for future refrigeration systems. A model for valve dynamics that links the fluid- and solid-dynamic effects can give fundamental insight and enable improvement of design. We developed such a model that combines computational fluid dynamics with finite element modeling. By computing gas flows and pressures during the valve actuation cycle using CFD, and computing the corresponding plate motion and impact at opening/closing using FEM, we are able to predict salient features of this system. We find that the damping at impact strongly affects the valve motion and the stress and strain on the ring plate. We observe that inhomogeneities in the pressure acting on the valve plate lead to small changes in plate orientation, that can be amplified through the impact into tumbling motion. Our findings are compared against experimental measurements obtained from instrumenting a real compressor.