Alden (Alden Research Laboratory, Inc.) is an internationally acclaimed leader in solving flow-related engineering and environmental problems. For 125 years, Alden has provided engineering, field, and laboratory technical assessments to address regulatory agency compliance and operational requirements. With laboratories in Massachusetts and Washington and office across the country, Alden provides engineering services, environmental services, physical and computational flow modeling, flow meter calibration, and field services. Founded in 1894, Alden is the oldest continuously operating hydraulic modeling and testing laboratory in North America.    Unusually large facilities (more than 125,000 square feet of enclosed space) and sophisticated data acquisition systems are available for each study. Approximately twenty buildings, located on thirty acres at our headquarters in Holden, Massachusetts are equipped with flow supplies and control systems for conducting hydraulic modeling, fish testing, air/gas flow modeling, and numerous other types of flow testing. In addition, Alden has a 10,000 square foot hydraulic modeling laboratory in Everett, Washington. Along with Alden’s laborator...y facilities on the east and west coasts, Alden offers hydraulic engineering and numerical modeling services to clients from offices in Fort Collins, Colorado; Littleton, Colorado; and Portland, Oregon. Alden maintains a wide variety of state-of-the-art numeric modeling programs and expertise, including several commercial CFD codes: ANSYS Fluent, FLOW-3D and STAR CCM+. Combining computational expertise with over a century's worth of experience in physical flow modeling gives Alden the unique ability to apply both in concert for cost-effective, practical solutions to our client’s flow problems. We have extensive experience and conducted numerous evaluations and hydraulic model studies of fresh water intakes, flood control pumping stations, sewerage pumping plants, cooling water intakes, reactor containment sumps, pump storage intake structures, and other pump intakes, all of which have required observations of approach flow patterns, identification of vortices, and evaluation of swirling flow approaching pumps. Alden has also conducted considerable research in the area of vortex formation and suppressors, and scale effects on vortices in Froude models. Members of our staff have written chapters for various handbooks and manuals on pump intakes and swirling flow. Andy Johansson, Director of Hydraulic Modeling at Alden, currently serves as the Vice Chair of the Hydraulic Institute (HI) Intake Design Committee and actively participates on the HI Pump Piping Standards Committee.