Water Tunnel in a Box: A Novel Small Footprint Flow Facility

Fluid dynamics experiments often require flow-producing facilities, which can involve large investments of time, money, and physical space. A traditional water tunnel involves one or several pumps which drive water around a circuit composed of a series of physically large and geometrically complicated guiding features including a diffuser, contraction, flow manipulators, and connecting pipes. An alternate design presented here leverages an array of electric thrusters to drive flow through an enclosed test section within a rectangular aquarium tank. In this arrangement, the test section is about 35% of the total fluid volume, with a test section footprint on the order of 45% the total tunnel footprint area. A combination of dye visualization and PIV results will be presented concerning the spatial and temporal uniformity of the flow field within the test section. Opportunities and challenges with this type of water tunnel will be discussed, including the potential for studying unsteady and impulsive flows, maintenance and operation considerations, and software tunable flow conditions.