Performance evaluation of orifice plate assemblies under non-standard conditions using CFD

The performance characteristics of small diameter orificemeters (diameter = 40 mm NB) for four diameter ratios with higher plate thicknesses are evaluated using computational fluid dynamics (CFD) under the non-standard conditions using water as the working fluid. The plate thicknesses considered are larger than the maximum allowed thickness specified in standard, ISO- 5167. The study has shown the effect of plate thickness on the value of Cd to be only marginal up to twice the allowable plate thickness for all the diameter ratios studied. The value of the Cd marginally decreases with increase in the plate thickness for lower β values, whereas the value of Cd increases with increase in plate thicknesses for higher β values.