Implementing weakly compressible flow

I have read that there is some literature to suggest that incompressible solvers fail to propagate mass flux accurately in pulsatile (transient) flows and this effect is worsened in FSI problems.

I suspect my simulation of pulsatile blood flow through a bi-leaflet prosthetic heart valve is prone to this- there is very low mass inflow at the inlet despite changing the time-step, domain size and inherent geometry. Are there any methods in Ansys CFX for treating the flow as weakly compressible? There are local sharp pressure drops near the leaflet at one point in the cycle but the flow overall is very much incompressible.

One paper "imposed a speed of sound of 15.7 m/s on the fluid (with the effective value being in the order of 1570 m/s)" but I'm not sure how to do this in CFX. I'm using the immersed boundary method (like the paper) and assuming rigid leaflets. Also, blood is nearly always assumed to be incompressible so there aren't any equations of state that I could program in for density (that I could find).


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