The tidal power has the potential to play a vital role in a sustainable energy future.The main objective of this paper is to investigate the performance and fatigue life of tidal current turbine(TCT)using fluid struct...The tidal power has the potential to play a vital role in a sustainable energy future.The main objective of this paper is to investigate the performance and fatigue life of tidal current turbine(TCT)using fluid structure interaction(FSI)modeling.The performance of TCT was predicted using Ansys CFX.The performance curve,pressure distribution on the blade,and velocity streamline were visualized for eight repetitive analyses at different tip speed ratio.The hydrodynamic load calculated from CFD analysis was transferred to FEA model for investigation of the structural response of TCT.Modal analysis was performed to examine the mode shapes and natural frequencies of TCT.The fatigue analysis were performed and number of cycles and safety factor at different equivalent alternating stresses were investigated.The results of the simulation confirm that the turbine has a maximum value of the coefficient of performance atλ=5,the turbine operating frequency is not close to its natural frequency,and it is safe under the applied fatigue loads with a high factor of safety.展开更多
This research provides conclusions that can partially cover the lack of knowledge related to the effects of ambient atmospheric conditions on DC electric power transportation.Two polymer insulating materials are used ...This research provides conclusions that can partially cover the lack of knowledge related to the effects of ambient atmospheric conditions on DC electric power transportation.Two polymer insulating materials are used for completing this research study.Inside a climate chamber,the relative humidity is controlled and adjusted from 20%to 80%RH.Then,the samples are charged with positive or negative charges by applying±20 kV to the corona-generating ring of needles.The surface potential is measured using an electrostatic voltmeter and is converted into surface charge density later by applying the probe response matrix method.The pre-charged samples are then stressed with high-voltage negative or positive DC values inside the climate chamber over a range of controlled values of the surrounding air humidity until flashover takes place.The space charges,which can drift in the air gap to reach the solid surface,are highly affected by the level of the relative humidity of the surrounding air.Also,increasing humidity results in a reduction of the DC flashover inception voltage and a shorter time to flashover regardless of the voltage polarity.Moreover,the positive or negative flashover inception voltage of both materials increases with pre-deposited negative charges while it decreases with pre-deposited positive charges.展开更多
文摘The tidal power has the potential to play a vital role in a sustainable energy future.The main objective of this paper is to investigate the performance and fatigue life of tidal current turbine(TCT)using fluid structure interaction(FSI)modeling.The performance of TCT was predicted using Ansys CFX.The performance curve,pressure distribution on the blade,and velocity streamline were visualized for eight repetitive analyses at different tip speed ratio.The hydrodynamic load calculated from CFD analysis was transferred to FEA model for investigation of the structural response of TCT.Modal analysis was performed to examine the mode shapes and natural frequencies of TCT.The fatigue analysis were performed and number of cycles and safety factor at different equivalent alternating stresses were investigated.The results of the simulation confirm that the turbine has a maximum value of the coefficient of performance atλ=5,the turbine operating frequency is not close to its natural frequency,and it is safe under the applied fatigue loads with a high factor of safety.
文摘This research provides conclusions that can partially cover the lack of knowledge related to the effects of ambient atmospheric conditions on DC electric power transportation.Two polymer insulating materials are used for completing this research study.Inside a climate chamber,the relative humidity is controlled and adjusted from 20%to 80%RH.Then,the samples are charged with positive or negative charges by applying±20 kV to the corona-generating ring of needles.The surface potential is measured using an electrostatic voltmeter and is converted into surface charge density later by applying the probe response matrix method.The pre-charged samples are then stressed with high-voltage negative or positive DC values inside the climate chamber over a range of controlled values of the surrounding air humidity until flashover takes place.The space charges,which can drift in the air gap to reach the solid surface,are highly affected by the level of the relative humidity of the surrounding air.Also,increasing humidity results in a reduction of the DC flashover inception voltage and a shorter time to flashover regardless of the voltage polarity.Moreover,the positive or negative flashover inception voltage of both materials increases with pre-deposited negative charges while it decreases with pre-deposited positive charges.
