局地热力强迫与准定常大振幅扰动的形成

LOCALIZED THERMAL FORCING AND FORMATION OFLARGE AMPLITUDE QUASISTEADY DISTURBANCES

文中导得了包括热力强迫和耗散的非线性强迫ＫｄＶ－Ｂｕｒｇｅｒｓ方程，并作了数值求解。计算结果表明，热力强迫和耗散是孤波质量和能量变化的主要原因，耗散使孤波质量能量随时间指数衰减；热力强迫与地形一样，都能在强迫区产生定常孤波，但前者产生的上游扰动振幅更大，而后者产生的下游扰动更为明显；加热和地形一样都能使孤波发生位相漂移，减小其移速，阻挡孤波的移动，从而增加与孤波的相互作用时间；适当大小的耗散与热力强迫的组合迫使移动性孤波在强迫区附近来回振荡，大大增加与热力强迫的相互作用时间；在耗散与热力强迫同时存在的非线性系统中，移动性孤波与热力强迫的相互作用可能是产生阻塞等长生命周期的局地准定常系统的重要因子。

 forced KdVBurgers equation including thermal forcing and dissipation is derived,and the numercal solutions are given.The numerical results show that forcing and dissipation are main sources of variation of mass and energy of the solitary waves,the thermal forcing can excite steady solitary waves in the forcing region and causes the phase shift of solitary wave and decreases its moving speed and increases time of interaction of thermal forcing with solitary wave.In nonlinear system with dissipation and thermal forcing the interaction of moving solitary wave with thermal forcing may be an important factor for generating the localized blocking.