The performance of Wells turbine under bi-directional airflow

This paper presents the performance of a Wells turbine operating under unsteady bi-directional airflow conditions. In this study, four kinds of blade profile were selected, NACA0020, NACA0015, CA9 and HSIM 15-262123-1576. The experiments have been carried out for two solidities under sinusoidal and irregular unsteady flow conditions based on Irish waves (Site2). It was found that for a Wells turbine operating under bi-directional air flow, the rotor geometry preferred is the blade profile of CA9 with rotor solidity σ=0.64. In addition, the efficiency curve of the Wells turbine under unidirectional flow conditions fails to present the rapid rise in the instantaneous efficiency which occurs at low flow coefficient of bi-directional flow condition. A comparative analysis between the numerical simulation results and experimental results was carried out. As a result, an excellent agreement was found between the numerical and experimental results. In addition, the effect of blade profile and rotor solidity on hysteretic characteristics of the turbine has been clarified experimentally under bi-directional airflow.

[1]  Manabu Takao,et al.  Effect of Blade Profile on the Performance of Large-Scale Wells Turbine , 2004 .

[2]  Manabu Takao,et al.  Effect of Rotor Geometry On the Performance of Wells Turbine , 2003 .

[3]  Toshiaki Setoguchi,et al.  Hysteretic characteristics of Wells turbine for wave power conversion , 2003 .

[4]  Srinivasan Raghunathan,et al.  Performance of the Wells self-rectifying air turbine , 1985 .

[5]  M. Inoue,et al.  Effect of Guide Vanes on the Performance of a Wells Turbine. , 1998 .

[6]  Toshiaki Setoguchi,et al.  The wells air turbine subjected to inlet flow distortion and high levels of turbulence , 1987 .

[7]  Manabu Takao,et al.  Study on an impulse turbine for wave energy conversion , 1999 .

[8]  A. Thakker,et al.  Experimental studies on effect of guide vane shape on performance of impulse turbine for wave energy conversion , 2005 .

[9]  Toshiaki Setoguchi,et al.  Studies on Wells Turbine for Wave Power Generator : 4th Report, Starting and Running Characteristics in Periodically Oscillating Flow , 1986 .

[10]  S Raghunathan,et al.  Noise characteristics of turbines for wave power conversion , 2001 .

[11]  M. Inoue,et al.  Performance comparison of turbines for wave power conversion , 2001 .

[12]  Luís M.C. Gato,et al.  Performance of a High-Solidity Wells Turbine for an OWC Wave Power Plant , 1996 .

[13]  Manabu Takao,et al.  Effect of blade profile on the performance of a large-scale Wells turbine for wave-energy conversion , 2006 .

[14]  Matthew Folley,et al.  Overview and Initial Operational Experience of the LIMPET Wave Energy Plant , 2002 .