OpenFlume: An accessible and reproducible benchtop flume for research and education

Open-channel flumes are an important tool in fluid mechanics research and education. However, the few commercially available small-scale flumes are generally expensive and lack complete characterization. In this work, we present a custom, low-cost, modular benchtop laboratory flume that is designed to be accessible and reproducible. The flume is assembled from commonly available materials and hardware and fabricated using a computer numerically controlled (CNC) router. Sections of the flume are mated using a standardized interface with a compression seal, allowing the flume components to be fabricated as discrete modules, rearranged into different configurations, and easily modified. Our design has a flow cross-section of 5 x 5 cm, adjustable flow velocity, and a modest footprint. The flow in the test section is characterized using particle image velocimetry (PIV) and shown to be of high uniformity and low turbulent intensity. Disturbances on the free surface are evaluated using an optical refraction-based method. A first application of the flume to study drag on partially immersed spheres will be briefly discussed.