Experimental validation of a linear momentum and bluff-body model for high-blockage cross-flow turbine arrays

The efficiency of an array of turbines operating in a channel is influenced by how much of the channel the array occupies, represented as the blockage ratio. In this work, the performance and near-wake flow field of a cross-flow turbine array are evaluated across a range of blockage ratios through laboratory experiments. An analytical linear momentum actuator disk model is found to be predictive of the measured velocity of the fluid that bypasses the array. When the array performance is scaled by the bypass velocity in a manner inspired by Maskell's bluff-body theory, self-similar performance is observed across blockage ratios, highlighting the salient dynamics of highly-confined turbines.