Augmenting Energy Capture in Low Energy Density Flows

Abstract

Marine hydrokinetic (MHK) technologies are emerging as a promising source of renewable energies given their ability to provide constant baseline power, predictable loading, and proximity to high density populations. An overlooked yet widely available source of marine energy are ocean currents: a low-energy density source. When considering the energy capture potential of a MHK turbine in low current speeds (\u3c 2 knots) the costs far outweigh the benefits. Pennsylvania State University (PSU) has proposed a novel technology that seeks to harness the power of low velocity ocean currents: Rapidly Deployable Parachute Augmented Turbine (RDPAT). A stream tube capture device (SCD) or flow augmenter integrated with an MHK turbine has the potential to accelerate flows, enabling meaningful energy capture. The SCD increases capture area and accelerates the flow into an MHK turbine, resulting in a lower weight to capture area ratio as compared to a standard ducted MHK turbine. These benefits as compared to standard ducted MHK turbines may reduce levelized cost of energy (LCOE) of the RD-PAT device. The goal of this master’s thesis is to collect high-quality flow data with low fidelity models at laboratory-scale in a hydraulic flume to verify the hypothesized flow field effects of SCDs. The collection and processing of velocity field and drag force measurements of models to characterize the flow around an SCD in unbounded flow is the primary objective of this study. Using the data to verify and inform a control volume analysis, an investigation will be done on the SCD to quantify fluid effects as a function of varied geometry