Valves are elements where computational fluid dynamics has been usually applied: their desing, characterization (calculation of flow coefficients) or the study of cavitation (prevention and calculation of coefficients, such as the cavitation index) have been typical applications of CFD.

Our experience with CFD simulation of valves

nablaDot has developed several studies related to valves, both for the calculation of flow coefficients as to prevent cavitation, in different sorts of valves. This has allowed nablaDot to gain a significant knowhow in this type of simulations.

Presión válvulas Líneas corriente válvulas

CFD model precision in valves

When dealing with a valve simulation, the geometric depiction (computational mesh) and the turbulence model chosen are important to achieve a good precision in the results. Thus, with coarse computational meshes and a standard turbulence model (RANS), typical deviations from the experimental data are around 20-30%. If we use standard turbulence models on fine meshes, the errors found are usually around 10%; finally, if we combine a fine mesh with and advanced turbulence models (LES), we can achieve very precise results, with deviations under a 5% from experimental measurements. The influence of the mesh and the turbulence model is especially important for the simulation of cases with the valve nearly closed; in such cases, the small section available for the flow should be modeled with higher detail; otherwise, deviations may be significant.

nablaDot can advise you to get a good compromise between high precision and low cost.