Application of Numerical and Experimental Modeling to Improve the Efficiency of Parshall Flumes: A Review of the State-of-the-Art

Abstract

One of the primary steps in managing the flow in an open channel is determining its properties. Empirical equations are developed to provide further information regarding the flow in open channels. Obtaining such experimental equations is expensive and time consuming; therefore, alternative solutions have been sought. Over the last century, the Parshall flume, a static measuring device with no moving parts, has played a significant role in measuring the flow in open channels. Many researchers have focused their interest on studying the application of Parshall flumes in various fields like irrigation and wastewater management. Although various scholars used experimental results to enhance the rating equation of the Parshall flume, others used an alternative source of data to recalibrate the height–discharge relation equation using numerical simulation. Computational Fluid Dynamic (CFD) software is becoming popular nowadays as computing hardware has advanced significantly within the last few decades, making it possible to go beyond the limited resolution that was experienced in the past. Multiple CFD models, depending on their availability, either open-source or commercially licensed, have been used to perform numerical simulations on different configurations of flumes, especially Parshall flumes, to produce water level results. Regarding various CFD tools that have been used, i.e., FLOW-3D, Ansys Fluent, or OpenFOAM, after precise calibration with experimental data, it has been determined that the output is reliable and can be implemented to the actual scenarios. The benefit of using this technique to produce results is the ability of the CFD approach to adjust the initial conditions, like flow velocity or structural geometry, where necessary. With respect to channel size and the condition of the site where the flume is located, the choices are narrowed to the specific Parshall flume suitable to the situation. It is not always possible to select the standard Parshall flume; therefore, engineers provide some modification to the closest flume size and provide a new rating curve to produce accurate flowrates. This review has been performed on the works of a number of scholars who targeted the application of numerical simulation and physical experimental data in Parshall flumes to either enhance the existing rating equation or propose further modification to the structure’s geometry.

Review of hydraulic performance of open‐channel flow‐measuring flumes

“…Flumes are commonly used to measure flow for various monitoring settings, such as field runoff, stormwater, municipal storm sewers, dam seepage discharge, industrial effluent discharge, watershed monitoring, irrigation canal discharge, ditch and furrow discharge, spring discharge, mine discharge, and stream gauging (Tekade et al, 2016, Heyrani et al, 2022Luxmi et al, 2022;Heiner and Barfuss, 2011;Marr et al, 2010;USBR, 2001;Todeschini et al, 2020;Ribeiro et al, 2021).…”

“…The Parshall flume was originally developed in 1926. After further improvements, in 1930, the flume was named after Ralph L. Parshall, the engineer who designed it (Heyrani et al, 2022). The flume consists of a converging section, a throat section, and diverging section.…”

“…The flume is also accurate in measuring discharge in a variety of applications. It has a flat bottom which makes installation easier than Parshall flumes (Willeitner et al, 2012;Heyrani et al, 2022).…”

Evaluation of Submergence Limit and Head Loss in Flow Measuring Flumes Using Flow-3d Predictive Modeling

“…Flow measuring umes (hereinafter referred to as umes) with central contraction have been introduced as a cost-effective and simple approach for measuring water in rectangular open ditches and channels as it does not require complex in ow and out ow transition (Samani 2017; Kolavani et al 2018; Ghare et al 2020). The process produces critical ow in the contracted section resulting in a short-throated ume with no need for extended in ow and out ow transition (Samani 2017; Heyrani et al 2022). The contraction in rectangular umes is achieved by placing half cylinders in a perpendicular position inside the channel (Samani 2017).…”

“…It has been reported that a possible error of up to 60% in the accuracy of umes could occur if the submergence ratio exceeds its limit and ow transitions from free ow to submerged condition. (Willeitner et al 2012;Goel et al 2015;Heyrani et al 2022).…”