This paper presents the comparison of a three dimensional Computational Fluid Dynamics (CFD) analysis with empirical performance data of a 0.6 m impulse turbine with fixed guide vanes used for wave energy power conver...This paper presents the comparison of a three dimensional Computational Fluid Dynamics (CFD) analysis with empirical performance data of a 0.6 m impulse turbine with fixed guide vanes used for wave energy power conversion. Pro-Engineer, Gambit and Fluent 6 were used to create a 3-D model of the turbine. A hybrid meshing scheme was used with hexahedral cells in the near blade region and tetrahedral and pyramid cells in the rest of the domain. The turbine has a hub-to-tip ratio of 0.6 and results were obtained over a wide range of flow coefficients. The model yielded a maximum efficiency of approximately 54% as compared to a maximum efficiency of around 49% from experiment. A degree of insight into flow behaviour, not possible with experiment, was obtained.展开更多
The Wells turbine for a wave power generator is a self-rectifying air turbine that is available for an energy conversion in an oscillating water-air column without any rectifying valve. The objective of this paper is ...The Wells turbine for a wave power generator is a self-rectifying air turbine that is available for an energy conversion in an oscillating water-air column without any rectifying valve. The objective of this paper is to compare the performances of the Wells turbines in which the profile of blade are NACA0020, NACA0015, CA9 and HSIM15-262123-1576 in the small-scale model testing. The running characteristics in the steady flow, the start and running characteristics in the sinusoidal flow and the hysteretic characteristics in the sinusoidal flow were investigated for four kinds of turbine. As a conclusion, the turbine in which the profile of blade is NACA0020 has the best performances among 4 turbines for the running and starting characteristics in the small-scale model testing.展开更多
This paper presents the work carried out to predict the behavior of a 0.6m impulse turbine with fixed guide vanes with 0.6hub-to-tip(H/T) ratio under real sea conditions.In order to predict the true performance of the...This paper presents the work carried out to predict the behavior of a 0.6m impulse turbine with fixed guide vanes with 0.6hub-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 ompressibility 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.展开更多
文摘This paper presents the comparison of a three dimensional Computational Fluid Dynamics (CFD) analysis with empirical performance data of a 0.6 m impulse turbine with fixed guide vanes used for wave energy power conversion. Pro-Engineer, Gambit and Fluent 6 were used to create a 3-D model of the turbine. A hybrid meshing scheme was used with hexahedral cells in the near blade region and tetrahedral and pyramid cells in the rest of the domain. The turbine has a hub-to-tip ratio of 0.6 and results were obtained over a wide range of flow coefficients. The model yielded a maximum efficiency of approximately 54% as compared to a maximum efficiency of around 49% from experiment. A degree of insight into flow behaviour, not possible with experiment, was obtained.
文摘The Wells turbine for a wave power generator is a self-rectifying air turbine that is available for an energy conversion in an oscillating water-air column without any rectifying valve. The objective of this paper is to compare the performances of the Wells turbines in which the profile of blade are NACA0020, NACA0015, CA9 and HSIM15-262123-1576 in the small-scale model testing. The running characteristics in the steady flow, the start and running characteristics in the sinusoidal flow and the hysteretic characteristics in the sinusoidal flow were investigated for four kinds of turbine. As a conclusion, the turbine in which the profile of blade is NACA0020 has the best performances among 4 turbines for the running and starting characteristics in the small-scale model testing.
文摘This paper presents the work carried out to predict the behavior of a 0.6m impulse turbine with fixed guide vanes with 0.6hub-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 ompressibility 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.
