Fundamental characteristics of charging of a dust particle and its dynamics in SOL/divertor plasma in tokamaks are studied. According to the OML （orbit motion limited） theory, the charging process is extremely faste...Fundamental characteristics of charging of a dust particle and its dynamics in SOL/divertor plasma in tokamaks are studied. According to the OML （orbit motion limited） theory, the charging process is extremely faster, with a charging time of nanoseconds, than the dynamics process of the dust particle in SOL/divertor plasma, with a characteristic time of mil- liseconds, which means that the local charge state can be taken as the equilibrium charge state. It was clarified that the equilibrium charge Zd, eq can be determined in the form of Zd, eq/RdTe, which is a function of both the normalized relative speed of plasma ion flow with respect to the velocity of the dust particle and the plasma temperature ratio. After the investigation of domi- nant forces acting on dust particles, the friction forces due to the plasma ion absorption and ion Coulomb scattering are found of the same order for the case of low relative speed. The critical radius of a dust particle, for which the gravity is larger than the friction forces due to plasma ions, is obtained.展开更多
文章针对纯电动中型客车传动系参数优化问题,以传动系中变速器的传动比为优化变量,以车辆动力性和经济性为优化目标,采用模型在环优化(non-optimization with model in loop,OML)方法,利用Simscape物理建模工具建立电动客车模型,结合带...文章针对纯电动中型客车传动系参数优化问题,以传动系中变速器的传动比为优化变量,以车辆动力性和经济性为优化目标,采用模型在环优化(non-optimization with model in loop,OML)方法,利用Simscape物理建模工具建立电动客车模型,结合带精英策略的非支配排序遗传算法(non-dominated sorting genetic algorithm NSGA-Ⅱ)对纯电动客车传动系参数进行优化,并基于最小二乘法组合赋权法进行Pareto解集选优确定出最优解。优化结果表明,利用OML方法在约束条件范围内合理地优化了变速器的传动比,加速时间和比能耗分别降低了6%和3.9%,达到了整车动力性和经济性协同优化的目的,为实车开发提供了理论参考。展开更多
基金supported in part by the JSPS-CAS Core-University Program in tile field of Plasma and Nuclear Fusion, the Grant-in-Aid for scientific research from Ministry of Education, Science and Culture of Japan (No. 19055005)tile Chinese National Magnetic Confinement Fusion Science Program (No. 2009GB106006)
文摘Fundamental characteristics of charging of a dust particle and its dynamics in SOL/divertor plasma in tokamaks are studied. According to the OML （orbit motion limited） theory, the charging process is extremely faster, with a charging time of nanoseconds, than the dynamics process of the dust particle in SOL/divertor plasma, with a characteristic time of mil- liseconds, which means that the local charge state can be taken as the equilibrium charge state. It was clarified that the equilibrium charge Zd, eq can be determined in the form of Zd, eq/RdTe, which is a function of both the normalized relative speed of plasma ion flow with respect to the velocity of the dust particle and the plasma temperature ratio. After the investigation of domi- nant forces acting on dust particles, the friction forces due to the plasma ion absorption and ion Coulomb scattering are found of the same order for the case of low relative speed. The critical radius of a dust particle, for which the gravity is larger than the friction forces due to plasma ions, is obtained.
文摘文章针对纯电动中型客车传动系参数优化问题,以传动系中变速器的传动比为优化变量,以车辆动力性和经济性为优化目标,采用模型在环优化(non-optimization with model in loop,OML)方法,利用Simscape物理建模工具建立电动客车模型,结合带精英策略的非支配排序遗传算法(non-dominated sorting genetic algorithm NSGA-Ⅱ)对纯电动客车传动系参数进行优化,并基于最小二乘法组合赋权法进行Pareto解集选优确定出最优解。优化结果表明,利用OML方法在约束条件范围内合理地优化了变速器的传动比,加速时间和比能耗分别降低了6%和3.9%,达到了整车动力性和经济性协同优化的目的,为实车开发提供了理论参考。
