Date of Thesis

5-30-2014

Thesis Type

Masters Thesis (Bucknell Access Only)

Degree Type

Master of Science in Mechanical Engineering

First Advisor

Maria Laura Beninati

Abstract

This laboratory study centered on the interaction of two model marine hydrokinetic turbines arranged in a stream-wise tandem configuration. The goal was to determine the effect of an upstream turbine on the performance of the downstream turbine. Specifically, the study focused on the changes in power generation that occurred as the stream-wise spacing between devices was varied. Understanding the interaction effect between laboratory scaled marine hydrokinetic devices is a necessary step prior to field deployment. Currently, only few laboratory studies have been performed addressing this issue and have approached the problem one-sidedly: solely looking at the thrust and power coefficients. This study analyzes multiple aspects of the research problem to provide a global overview on the interaction between two devices. Testing is conducted in the hydraulic flume facility (9.8 m long, 1.2 m wide and 0.4 m deep) at Bucknell University. The devices are two-bladed model marine turbines with a rotor diameter of 0.1 m. Multiple tests are performed for a fixed range of separation distances between the two devices. For each separation distance, thrust and generated power of both devices was measured. Moreover, the velocity profile and turbulence intensity incident on the downstream device was determined for each case. Results demonstrate that the performance of a downstream device is affected by the presence of the upstream turbine. The evolution of the wake velocity and turbulence intensity is strongly related to the power generation levels of the downstream marine hydrokinetic device. Results show that an ideal separation distance exists between devices such that the power generation and performance of the downstream marine hydrokinetic device are maximized.

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