An Analysis of the Hydrokinetic Turbine in Free-Flow Conditions

In this research, the flow around a hydrokinetic turbine within a channel is controlled with a diffuser. A simulation model for a channel width and height of 150 mm is developed and experimentally validated. For a flow speed of 0.33 m/s the diffuser was found to experimentally augment the available power within the flow by a factor of 1.96. A turbine was modelled as a 1-dimensional actuator disk model and several diffuser-turbine variables were studied. Tip gap, nacelle cover size as well as drag distribution along the actuator disk model were studied and observations were made on differences in pressure, theoretical power, and disk loading at a channel speed of 0.5 m/s. The theoretical maximum power for the optimized diffuser that could be extracted from the flow was found to be 0.26 W at a minimal pressure difference of 238.29 Pa, and a disk loading of 1.46 N.