[sazrul]

Hello,

I am currently doing the CFD analysis for cylinder head air flow measurement. My job is to correlate the mass flow rate from steady-state flow bench result with CFD simulation result. One of the item that i need to correlate is the flow coefficient value. My question is, how should I calculate the flow coefficient in Star-CCM+? Does the formula similar with the experimental application? From literature that I have read, flow coefficient is given by this equation:

Flow coefficient = mdot actual / mdot theory.

where;

mdot theory = valve seat area x flow velocity.

Thank you,
sazrul

[fluid23]

I think you answered your own question. If you know theoretical mass flow and you know the 'actual' mass flow from CFD then you have your flow coefficient. Are you trying to get the software to calculate it?

If that's the case then you need to setup a mass flow report at an appropriate location (i.e. not at a boundary condition) and then an expression report that takes the ratio of your mass flow report / mass flow theory.