Water Online

May 2017

Water Innovations gives Water and Wastewater Engineers and end-users a venue to find project solutions and source valuable product information. We aim to educate the engineering and operations community on important issues and trends.

Issue link: https://wateronline.epubxp.com/i/816402

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Page 35 of 38

While CFD is considered a valuable and important tool for enhancing the value of physical model studies, it is still far from being able to replace physical models for pump intake modeling. impeller. A standardized system was also established to classify free and subsurface vortex activity. Acceptable preswirl, velocity distribution, and vortex activity were defined based on experience gained over many years comparing physical models and prototype operation. A physical model study conducted in accordance with the HI criteria by laboratories experienced with pump intake modeling should provide the same results, regardless of the organization. About 15 years ago, Alden and others started experimenting with the use of CFD for pump intake modeling. CFD is unreliable at predicting the time-dependent unstable vortices that can be characteristic of pump intakes; however, the allure of a faster and more cost-effective modeling approach was significant. In the ensuing time, computers have become much more powerful, and CFD model codes and methods have improved, albeit at a slower pace. Among civil engineering firms, Alden is one of the largest users of CFD in North America based on number of licenses in use. Alden also conducts 10 to 15 physical models of pump intakes each year, uniquely positioning Alden to conduct ongoing comparisons between CFD and physical model results. The research to date has failed to produce reliable CFD results for predicting pump intake performance. The Present In 2016, the HI invited leading CFD engineers from around the world to participate in a forum regarding the state of the art in CFD modeling of pump intakes. The modelers present all used a variety of CFD codes and turbulence models, including large eddy simulations (LES) run on wateronline.com n Water Innovations 33 PUMPSYSTEMS Innovative Chemical Feed Solutions * * NEW PRODUCT * * Model 4180 Chlorine Dioxide Generator Safely and Accurately I ntroduce Chlorine Gas and Sodium Chlorite Simultaneously into Feed Water Stream - Feed Range of 0-500ppd - Accuracy of +/- 2% of Actual Feed - 4 Control Modes - 2.5hr of Battery Backup -Air Binding and Etching NOT Possible -Metering to Validate Actual Flow Rate -Automatically Regulates in Fixed and Variable Control Modes - Can be Remotely Monitored and Controlled by SCADA JCS Industries, Inc. I PO Box 90028 I Houston, TX 77290 Ph: 281-353-2100 I www.jcsindustries.us.com

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