A New Correlation for Single-Phase Pressure Loss through SMV Static Mixers at High Reynolds Numbers

Abstract Robust, scalable correlations for pressure loss across corrugated (SMV-style) static mixers at high Reynolds (Re) numbers are currently lacking. To address this, results from an experimental and computational fluid dynamics (CFD) based study involving a single SMV mixing element for Re in the range of 8,000 – 250,000 is reported. The investigated scenarios encompassed three different pipe diameters and variations in the wall roughness. The equivalent sand grain roughness was first estimated from measurements in an empty pipe and provided as an input to the CFD model. The agreement between the CFD predictions and measurements ascertained the validity of the roughness estimate. When the mixing element was absent, roughness contributed about 70-90% of the pressure losses in the rough stainless steel pipes and up to 7% of the losses in the smooth PVC pipe. A capillary model based semi-analytical correlation was developed to generalize the pressure loss characteristics when the mixing element was present. The proposed correlation captured both current and historical pressure loss measurements with an improved accuracy over currently available correlations. Even when with the mixing element present, about 60% of the pressure losses were attributed to the inclusion of wall roughness.