正压无辐散模式中双涡的相互作用

本文在无环境流场的情况下,利用正压无辐散模式对双涡的相互作用以及β效应的影响进行了数值模拟研究。一系列的试验结果表明:双涡的相对运动对双涡间的初始距离及双涡的相对强度是十分敏感的,双涡间的非线性涡度平流可导致两个系统的气旋隆互旋;同时可造成两个系统的相互吸引和合并或相互排斥,吸引或排斥的临界距离取决于双涡的结构及相对强度:"合并"的快慢取决于双涡的联合强度,联合强度越强越难于"合并"β效应对双涡的相互作用具有显著的影响。它可以改变双涡相互吸引或排斥的性质,还可以使两个相互吸引的同等强度的涡旋"合并"后较平直地向西北方向漂移,而使两个不同强度的涡旋"合并"后的运动表现为β漂移和陀螺运动的叠加。 

INTERACTIONS OF BINARY VORTICES IN A NONDIVERGENT BAROTROPIC MODEL

In this paper, the interactions between two cyclonic vortices in the absence of environmental flow and β effect on them are simulated using a nondivergent barotropic model.A series of experimental results show that the relative movments of binary vortices are very sensitive to the initial distance between them and each relative strength and that the nonlinear vorticity abvection from one vortex to the other can lead to mutual cyclonic rotation and attraction, mergence or repelling which relies on their structure and relative intensity for the critical separation. The stronger the combined intensity, the more difficult the vortices merge into one. β effect plays an important role in the interaction of the dual vortices in that it changes the nature of the mutual attraction and repelling, and results in either smooth drift towards northwest for a merged vortex from components with equal strength, or superposition of β effect and gyroidal movement for that with inepual strength.