An analytical model of a floating heaving box integrated with a vertical flexible porous membrane placed right next to the box applications to wave energy extraction and breakwater systems is developed under the reduc...An analytical model of a floating heaving box integrated with a vertical flexible porous membrane placed right next to the box applications to wave energy extraction and breakwater systems is developed under the reduced wave equation.The theoretical solutions for the heave radiating potential to the assigned physical model in the corresponding zones are attained by using the separation of variables approach along with the Fourier expansion.Applying the matching eigenfunction expansion technique and orthogonal conditions,the unknown coefficients that are involved in the radiated potentials are determined.The attained radiation potential allows the computation of hydrodynamic coefficients of the heaving buoy,Power Take-Off damping,and wave quantities.The accuracy of the analytical solution for the hydrodynamic coefficients is demonstrated for different oblique angles with varying numbers of terms in the series solution.The current analytical analysis findings are confirmed by existing published numerical boundary element method simulations.Several numerical results of the hydrodynamic coefficients,power capture,power take-off optimal damping,and transmission coefficients for numerous structural and physical aspects are conducted.It has been noted that the ideal power take-off damping increases as the angle of incidence rises,and the analysis suggests that the ability to capture waves is more effective in shallower waters compared to deeper ones.展开更多
Wave energy is a promising form of marine renewable energy that offers a sustainable pathway for electricity generation in coastal regions.Despite Malaysia’s extensive coastline,the exploration of wave energy in Sara...Wave energy is a promising form of marine renewable energy that offers a sustainable pathway for electricity generation in coastal regions.Despite Malaysia’s extensive coastline,the exploration of wave energy in Sarawak remains limited due to economic,technical,and environmental challenges that hinder its implementation.Compared to other renewable energy sources,wave energy is underutilized largely because of cost uncertainties and the lack of local performance data.This research aims to identify themost suitable coastal zone in Sarawak that achieves an optimal balance between energy potential,cost-effectiveness,and environmental impact,particularly in relation to infrastructure and regional development.The findings indicate that wave energy generation in Sarawak is technically feasible based on MOGA analysis.Among the studied sites,Bintulu emerged as the most balanced option,with a levelized cost of electricity(LCOE)of 0.778–0.864 USD/kWh and a CO_(2) emission factor as low as 0.019–0.020 CO_(2)/k Wh.Miri,while producing lower emissions than Sematan,recorded a higher LCOE of 1.045 USD/kWh with moderate emissions at 0.029 CO_(2)/kWh.Sematan,characterized by weaker wave conditions and higher installation penalties,resulted in the least favorable outcome,with an LCOE of 3.735 USD/kWh.Bintulu’s strategic location reduces CAPEX requirements,making it the most suitable site for large-scale wave energy deployment in Sarawak.展开更多
开发和利用可再生能源是解决能源危机的重要途径。波浪能作为一种可再生能源引起了世界各国的关注,其中振荡水柱(Oscillating Water Column,OWC)式波能装置是一种应用最广泛的波浪能转换技术。关于OWC的研究多集中于如何提高能量转换效...开发和利用可再生能源是解决能源危机的重要途径。波浪能作为一种可再生能源引起了世界各国的关注,其中振荡水柱(Oscillating Water Column,OWC)式波能装置是一种应用最广泛的波浪能转换技术。关于OWC的研究多集中于如何提高能量转换效率,但是由于海况的复杂性,装置面临很大的生存压力,提高装置的生存能力变得愈加重要。透空式防波堤形式已经有很多应用,它对高频短波消浪效果很好,对低频长波则较差,而振荡水柱波能装置对长波吸收能力较强。该研究将透空式防波堤和OWC装置有效结合起来,基于线性势流理论,运用分离变量法和特征函数匹配法建立了解析模型,研究了单独透空式防波堤形式下,不同开孔率对反射系数的影响;之后研究了集成系统下透空结构与OWC装置距离对反射系数、水动力效率等的影响,并与单独透空式防波堤和单独OWC装置对比,说明集成装置消浪的优越性。展开更多
待分解信号复杂度增大时传统单信号分解技术易产生过高特征空间维度的高频本征模态函数(intrinsic mode function,IMF),从而严重限制了长短时记忆神经网络(long short term memory,LSTM)的长时序预报能力。以舟山群岛南部外海某观测点...待分解信号复杂度增大时传统单信号分解技术易产生过高特征空间维度的高频本征模态函数(intrinsic mode function,IMF),从而严重限制了长短时记忆神经网络(long short term memory,LSTM)的长时序预报能力。以舟山群岛南部外海某观测点所收集的海浪数据为基础,提出融合ICEEMDAN-VMD级联分解策略和LSTM的混合模型。该混合模型准确捕捉海洋波浪的非线性特征和长时序依赖规律,提高了复杂海况下对有效波高、有效波周期、波向的长时预报能力。与多变量LSTM模型相比,混合模型的48 h和72 h有效波高预测均方根误差(root mean square error,RMSE)降幅分别为53.9%和33.8%,有效波周期预测RMSE降幅分别为46.1%和39.1%,波向预测RMSE降幅分别为30.5%和23.9%。与EMD-LSTM模型相比,混合模型有效波高、有效波周期、波向的RMSE平均降幅分别为13.52%、17.79%、15.39%。展开更多
基金Open access funding provided by FCT|FCCN(b-on)the Strategic Research Plan of the Centre for Marine Technology and Ocean Engineering(CENTEC),which is financed by the Portuguese Foundation for Science and Technology(Fundação para a Ciência e Tecnologia-FCT)under contract UIDB/UIDP/00134/2020.
文摘An analytical model of a floating heaving box integrated with a vertical flexible porous membrane placed right next to the box applications to wave energy extraction and breakwater systems is developed under the reduced wave equation.The theoretical solutions for the heave radiating potential to the assigned physical model in the corresponding zones are attained by using the separation of variables approach along with the Fourier expansion.Applying the matching eigenfunction expansion technique and orthogonal conditions,the unknown coefficients that are involved in the radiated potentials are determined.The attained radiation potential allows the computation of hydrodynamic coefficients of the heaving buoy,Power Take-Off damping,and wave quantities.The accuracy of the analytical solution for the hydrodynamic coefficients is demonstrated for different oblique angles with varying numbers of terms in the series solution.The current analytical analysis findings are confirmed by existing published numerical boundary element method simulations.Several numerical results of the hydrodynamic coefficients,power capture,power take-off optimal damping,and transmission coefficients for numerous structural and physical aspects are conducted.It has been noted that the ideal power take-off damping increases as the angle of incidence rises,and the analysis suggests that the ability to capture waves is more effective in shallower waters compared to deeper ones.
基金supported by Swinburne University of Technology Sarawak Campus and Birmingham City University.
文摘Wave energy is a promising form of marine renewable energy that offers a sustainable pathway for electricity generation in coastal regions.Despite Malaysia’s extensive coastline,the exploration of wave energy in Sarawak remains limited due to economic,technical,and environmental challenges that hinder its implementation.Compared to other renewable energy sources,wave energy is underutilized largely because of cost uncertainties and the lack of local performance data.This research aims to identify themost suitable coastal zone in Sarawak that achieves an optimal balance between energy potential,cost-effectiveness,and environmental impact,particularly in relation to infrastructure and regional development.The findings indicate that wave energy generation in Sarawak is technically feasible based on MOGA analysis.Among the studied sites,Bintulu emerged as the most balanced option,with a levelized cost of electricity(LCOE)of 0.778–0.864 USD/kWh and a CO_(2) emission factor as low as 0.019–0.020 CO_(2)/k Wh.Miri,while producing lower emissions than Sematan,recorded a higher LCOE of 1.045 USD/kWh with moderate emissions at 0.029 CO_(2)/kWh.Sematan,characterized by weaker wave conditions and higher installation penalties,resulted in the least favorable outcome,with an LCOE of 3.735 USD/kWh.Bintulu’s strategic location reduces CAPEX requirements,making it the most suitable site for large-scale wave energy deployment in Sarawak.
文摘开发和利用可再生能源是解决能源危机的重要途径。波浪能作为一种可再生能源引起了世界各国的关注,其中振荡水柱(Oscillating Water Column,OWC)式波能装置是一种应用最广泛的波浪能转换技术。关于OWC的研究多集中于如何提高能量转换效率,但是由于海况的复杂性,装置面临很大的生存压力,提高装置的生存能力变得愈加重要。透空式防波堤形式已经有很多应用,它对高频短波消浪效果很好,对低频长波则较差,而振荡水柱波能装置对长波吸收能力较强。该研究将透空式防波堤和OWC装置有效结合起来,基于线性势流理论,运用分离变量法和特征函数匹配法建立了解析模型,研究了单独透空式防波堤形式下,不同开孔率对反射系数的影响;之后研究了集成系统下透空结构与OWC装置距离对反射系数、水动力效率等的影响,并与单独透空式防波堤和单独OWC装置对比,说明集成装置消浪的优越性。
文摘待分解信号复杂度增大时传统单信号分解技术易产生过高特征空间维度的高频本征模态函数(intrinsic mode function,IMF),从而严重限制了长短时记忆神经网络(long short term memory,LSTM)的长时序预报能力。以舟山群岛南部外海某观测点所收集的海浪数据为基础,提出融合ICEEMDAN-VMD级联分解策略和LSTM的混合模型。该混合模型准确捕捉海洋波浪的非线性特征和长时序依赖规律,提高了复杂海况下对有效波高、有效波周期、波向的长时预报能力。与多变量LSTM模型相比,混合模型的48 h和72 h有效波高预测均方根误差(root mean square error,RMSE)降幅分别为53.9%和33.8%,有效波周期预测RMSE降幅分别为46.1%和39.1%,波向预测RMSE降幅分别为30.5%和23.9%。与EMD-LSTM模型相比,混合模型有效波高、有效波周期、波向的RMSE平均降幅分别为13.52%、17.79%、15.39%。
