A twin unidirectional impulse turbine topology for OWC based wave energy plants

We investigate the different factors affecting the performance of an OWC chamber. We carry out a comprehensive campaign of physical model tests (387 in total). The turbine damping is the main factor, taking precedence over the wave conditions. The wave period is far more important than the wave height. The tidal level plays a significant role under certain wave conditions.

Performance of OWC wave energy converters: influence of turbine damping and tidal variability

Computed effects of tip clearance on performance of impulse turbine for wave energy conversion

Non-dimensional analysis for matching an impulse turbine to an OWC (oscillating water column) with an optimum energy transfer

Multi-point aerodynamic optimization of the rotor blade sections of an axial-flow impulse air turbine for wave energy conversion

Effects of turbine damping on performance of an impulse turbine for wave energy conversion under different sea conditions using numerical simulation techniques

Wave energy is the most abundant source of renewable energy in the World. For the last two decades, engineers have been investigating and defining different methods for power extraction from wave motion. Two different turbines, namely Wells turbine and impulse turbine with guide vanes, are most commonly used around the world for wave energy power generation. The ultimate goal is to optimize the performance of the turbine under actual sea conditions. The total research effort has several strands; there is the manufacture and experimental testing of new turbines using the Wave Energy Research Team's (WERT) 0.6 m turbine test rig, the theoretical and computational analysis of the present impulse turbine using a commercial software package and finally the prediction of the performance of the turbine in a representative wave power device under real sea conditions using numerical simulation. Also, the WERT 0.6 m turbine test rig was upgraded with a data acquisition and control system to test the turbine in the laboratory under real sea conditions using the computer control system. As a result, it is proven experimentally and numerically that the turbine efficiency has been raised by 7% by reducing the hub-to-tip ratio from 0.7 to 0.6. Effect of tip clearance on performance of the turbine has been studied numerically and designed tip clearance ratio of 1% has been validated. From the numerical simulation studies, it is computed that the mean conversion efficiency is reduced around 5% and 4.58% due to compressible flow and damping effects inside OWC device. Copyright © 2005 John Wiley & Sons, Ltd.

Design and performance analysis of impulse turbine for a wave energy power plant

This paper presents the work carried out to predict the behavior of a 06 m Impulse turbine with fixed guide vanes with 06 hub-to-tip (H/T) ratio under real sea conditions In order to predict the true performance of the actual Oscillating Water Column (OWC), the numerical technique has been fine tuned by incorporating the compressibility effect Water surface elevation verses time history based on Pierson Moskowitz Spectra was used as the input data Standard numerical techniques were employed to solve the non-linear behavior of the sea waves The effect due to compressibility inside the air chamber and turbine performance under unsteady and irregular flow condition has been analyzed numerically Considering the quasi-steady assumptions, unidirectional steady flow experimental data was used to simulate the turbine characteristics under irregular unsteady flow conditions The results show that the performance of this type of turbine is quite stable and efficiency of air chamber and the mean conversion efficiency is reduced around 8% and 5% respectively, due to compressibility inside air chamber

Zia Usmani

Papers

Effects of turbine damping on performance of an impulse turbine for wave energy conversion under different sea conditions using numerical simulation techniques

Design and performance analysis of impulse turbine for a wave energy power plant

Application of Numerical Simulation Method to Predict the Performance of Wave Energy Device with Impulse Turbine