Based on an integral equation method,the unsteady supercavitating flow around a slender cone cavitator is studied.The shape and length of supercavity is calculated respectively by using a finite difference time discre...Based on an integral equation method,the unsteady supercavitating flow around a slender cone cavitator is studied.The shape and length of supercavity is calculated respectively by using a finite difference time discrete method.Their characteristics varying with the cone angle and cavitation number are investigated respectively.It can be seen obviously that the change of supercavity is characterized by retardation and waviness.展开更多
单一线性锥规划方法求解最优潮流(optimal power flow,OPF)问题时,锥变量仅局限于某个单一锥集合,使得锥规划模型的构造缺乏灵活性,建模难度较大。为此,基于混合线性锥规划(mixed cone linear programming,MCLP)方法,提出了求解OPF问题...单一线性锥规划方法求解最优潮流(optimal power flow,OPF)问题时,锥变量仅局限于某个单一锥集合,使得锥规划模型的构造缺乏灵活性,建模难度较大。为此,基于混合线性锥规划(mixed cone linear programming,MCLP)方法,提出了求解OPF问题的3种MCLP模型—MCLP-OPF。该模型采用不同的锥变量来构建原始OPF问题的锥松弛模型,锥变量可同时取自半正定锥、二阶锥和非负多面体锥。引入MCLP-OPF问题的可行域"厚度",并根据该"厚度"大小选择直接内点法或齐次自对偶(homogeneous self-dual,HSD)内点法求解。从C-703节点等6个测试系统的仿真结果可以看到,相较于半定规划法,MCLP-OPF提高了锥规划方法的建模效率、求解效率和存储效率,更适于求解大规模电力系统问题。展开更多
文摘Based on an integral equation method,the unsteady supercavitating flow around a slender cone cavitator is studied.The shape and length of supercavity is calculated respectively by using a finite difference time discrete method.Their characteristics varying with the cone angle and cavitation number are investigated respectively.It can be seen obviously that the change of supercavity is characterized by retardation and waviness.
文摘单一线性锥规划方法求解最优潮流(optimal power flow,OPF)问题时,锥变量仅局限于某个单一锥集合,使得锥规划模型的构造缺乏灵活性,建模难度较大。为此,基于混合线性锥规划(mixed cone linear programming,MCLP)方法,提出了求解OPF问题的3种MCLP模型—MCLP-OPF。该模型采用不同的锥变量来构建原始OPF问题的锥松弛模型,锥变量可同时取自半正定锥、二阶锥和非负多面体锥。引入MCLP-OPF问题的可行域"厚度",并根据该"厚度"大小选择直接内点法或齐次自对偶(homogeneous self-dual,HSD)内点法求解。从C-703节点等6个测试系统的仿真结果可以看到,相较于半定规划法,MCLP-OPF提高了锥规划方法的建模效率、求解效率和存储效率,更适于求解大规模电力系统问题。
