论文部分内容阅读
当海洋工程结构物或水下航行器在海洋中遭遇异常大振幅内波时可造成损害甚至失事,海洋内孤立波斜相互作用的Mach效应是一种特殊海洋现象,也是异常大振幅内孤立波的重要成因.为了在实验室模拟具有海洋跃层环境中的内孤立波斜相互作用并控制Mach效应的产生,首先将两只直立无底圆柱筒放置在淡/盐水分布的两层流体环境中,淡/盐水混合区模拟海洋密度跃层,保持筒底与筒外水体的交换,以方便形成筒内外混合区的高度差;再将两柱筒平稳迅速移出,利用柱筒内外淡/盐水混合区高度差的重力塌陷扰动形成两列内孤立波,其在交汇区发生斜相互作用,并借助高清图像处理技术结合几何射线方法完成测量.实验结果表明:两列内孤立波斜相互作用性质取决于分层环境、两柱筒之间距离以及两列内孤立波的波幅和相位,上述方法可有效控制分层流实验水槽中Mach效应的产生.进一步分析表明:两列内孤立波相互作用的Mach效应将导致波幅显著增强,传播速度明显增大,且传播方向受两者振幅大小的控制,振幅相差越大所产生Mach效应的临界夹角越大.此外,通过内孤立波斜相互作用的Mach效应实验结果与Kd V,BO和MCC三种理论模型的比较,实验验证了Mach效应对非线性理论模型的适应性.
When the ocean engineering structure or underwater vehicle encounters an abnormally large amplitude internal wave in the ocean, it can cause damage or even crash. The Mach effect of the isolated wave oblique interaction in the ocean is a special ocean phenomenon and is also an unusual large-amplitude solitary wave .In order to simulate the internal solitary wave oblique interaction in a marine thermocline environment and control the Mach effect in the laboratory, two upright and bottomless cylinders were first placed in a two-layer fluid environment with light / brine distribution , Light / brine mixed zone to simulate the marine thermocline, to maintain the exchange between the bottom of the cylinder and the outside of the cylinder, in order to facilitate the formation of mixing height difference between the inside and outside the cylinder; and then quickly and smoothly out of the two column cylinder, The two regions of internal solitary wave perturbed by the gravity collapse of the regional height difference and their oblique interaction occurred in the intersection area, and the measurement was done by means of high-definition image processing combined with the geometric ray.The experimental results show that the nature of the solitary wave oblique interaction in two columns depends on The above method can effectively control the Mach effect in the stratified flow experiment tank in stratified environment, the distance between the two columns and the amplitude and phase of the solitary waves in two columns The further analysis shows that the Mach effect of the soliton wave interaction in the two columns will lead to the significant increase of the amplitude and the increase of the propagation velocity, and the propagation direction is controlled by the amplitudes of the two. In addition, by comparing the experimental results of Mach effect with the isolated wave oblique interaction with the three theoretical models of Kd V, BO and MCC, the adaptability of the Mach effect to the nonlinear theoretical model is experimentally verified.