In this paper,a fusion model based on a long short-term memory(LSTM)neural network and enhanced search ant colony optimization(ENSACO)is proposed to predict the power degradation trend of proton exchange membrane fuel...In this paper,a fusion model based on a long short-term memory(LSTM)neural network and enhanced search ant colony optimization(ENSACO)is proposed to predict the power degradation trend of proton exchange membrane fuel cells(PEMFC).Firstly,the Shapley additive explanations(SHAP)value method is used to select external characteristic parameters with high contributions as inputs for the data-driven approach.Next,a novel swarm optimization algorithm,the enhanced search ant colony optimization,is proposed.This algorithm improves the ant colony optimization(ACO)algorithm based on a reinforcement factor to avoid premature convergence and accelerate the convergence speed.Comparative experiments are set up to compare the performance differences between particle swarm optimization(PSO),ACO,and ENSACO.Finally,a data-driven method based on ENSACO-LSTM is proposed to predict the power degradation trend of PEMFCs.And actual aging data is used to validate the method.The results show that,within a limited number of iterations,the optimization capability of ENSACO is significantly stronger than that of PSO and ACO.Additionally,the prediction accuracy of the ENSACO-LSTM method is greatly improved,with an average increase of approximately 50.58%compared to LSTM,PSO-LSTM,and ACO-LSTM.展开更多
水面起飞性能是水面飞行器的基本性能,也是总体技术的核心,涉及多个学科领域。水陆两栖飞机水面高速滑行水动力性能与排水型船不同,具有速度高、运动复杂等特点,高速滑行时一方面受到较大的水动升力,另一方面受到机翼的升力。结合水陆...水面起飞性能是水面飞行器的基本性能,也是总体技术的核心,涉及多个学科领域。水陆两栖飞机水面高速滑行水动力性能与排水型船不同,具有速度高、运动复杂等特点,高速滑行时一方面受到较大的水动升力,另一方面受到机翼的升力。结合水陆两栖飞机水面高速滑行特点,利用雷诺平均法(Reynolds average navier-stokes, RANS)数值方法和重叠网格技术对水陆两栖飞机全机模型开展数值仿真模拟,分析了自由液面水气分布、机身底部压力分布特征,并将阻力、姿态和升沉与水池模型试验结果进行对比,验证了数值方法的准确性,为水陆两栖飞机静水滑行水动性能数值预报提供技术基础。展开更多
以时均化的N-S方程和考虑旋转与曲率影响的修正的k-湍流模型为基础,在贴体坐标系中运用S IM PLEC算法,对双吸式离心叶轮内流进行三维湍流数值模拟。计算得到叶轮内的速度、压力场分布,预估了扬程、水力效率并与试验值进行对比。计算结...以时均化的N-S方程和考虑旋转与曲率影响的修正的k-湍流模型为基础,在贴体坐标系中运用S IM PLEC算法,对双吸式离心叶轮内流进行三维湍流数值模拟。计算得到叶轮内的速度、压力场分布,预估了扬程、水力效率并与试验值进行对比。计算结果表明,在双吸式叶轮中,从叶轮进口到出口压力逐渐增加;在叶片区域,处于前盖板和对称面之间的中间截面上,叶片工作面附近的压力明显大于背面附近的压力,且从对称面到前盖板各中间截面上的压力梯度显著增加;流动关于对称面对称,在对称面上不存在轴向速度;设计工况下叶轮出口断面上压力分布明显比其它工况均匀,因此水力效率最高。展开更多
基金Supported by the Major Science and Technology Project of Jilin Province(20220301010GX)the International Scientific and Technological Cooperation(20240402071GH).
文摘In this paper,a fusion model based on a long short-term memory(LSTM)neural network and enhanced search ant colony optimization(ENSACO)is proposed to predict the power degradation trend of proton exchange membrane fuel cells(PEMFC).Firstly,the Shapley additive explanations(SHAP)value method is used to select external characteristic parameters with high contributions as inputs for the data-driven approach.Next,a novel swarm optimization algorithm,the enhanced search ant colony optimization,is proposed.This algorithm improves the ant colony optimization(ACO)algorithm based on a reinforcement factor to avoid premature convergence and accelerate the convergence speed.Comparative experiments are set up to compare the performance differences between particle swarm optimization(PSO),ACO,and ENSACO.Finally,a data-driven method based on ENSACO-LSTM is proposed to predict the power degradation trend of PEMFCs.And actual aging data is used to validate the method.The results show that,within a limited number of iterations,the optimization capability of ENSACO is significantly stronger than that of PSO and ACO.Additionally,the prediction accuracy of the ENSACO-LSTM method is greatly improved,with an average increase of approximately 50.58%compared to LSTM,PSO-LSTM,and ACO-LSTM.
文摘水面起飞性能是水面飞行器的基本性能,也是总体技术的核心,涉及多个学科领域。水陆两栖飞机水面高速滑行水动力性能与排水型船不同,具有速度高、运动复杂等特点,高速滑行时一方面受到较大的水动升力,另一方面受到机翼的升力。结合水陆两栖飞机水面高速滑行特点,利用雷诺平均法(Reynolds average navier-stokes, RANS)数值方法和重叠网格技术对水陆两栖飞机全机模型开展数值仿真模拟,分析了自由液面水气分布、机身底部压力分布特征,并将阻力、姿态和升沉与水池模型试验结果进行对比,验证了数值方法的准确性,为水陆两栖飞机静水滑行水动性能数值预报提供技术基础。
文摘以时均化的N-S方程和考虑旋转与曲率影响的修正的k-湍流模型为基础,在贴体坐标系中运用S IM PLEC算法,对双吸式离心叶轮内流进行三维湍流数值模拟。计算得到叶轮内的速度、压力场分布,预估了扬程、水力效率并与试验值进行对比。计算结果表明,在双吸式叶轮中,从叶轮进口到出口压力逐渐增加;在叶片区域,处于前盖板和对称面之间的中间截面上,叶片工作面附近的压力明显大于背面附近的压力,且从对称面到前盖板各中间截面上的压力梯度显著增加;流动关于对称面对称,在对称面上不存在轴向速度;设计工况下叶轮出口断面上压力分布明显比其它工况均匀,因此水力效率最高。
