On inertial flow over topography. Part 1. Semigeostrophic adjustment to an obstacle
On inertial flow over topography. Part 1. Semigeostrophic adjustment to an obstacle
复制标题
关于地形上的惯性流。
DOI：
10.1017/s0022112083001299
复制
发表时间：
1983
影响因子：
3.7
通讯作者：
L. Pratt
中科院分区：
文献类型：
--
作者：
L. Pratt
本文研究了均质明渠水流对障碍物突遇的非线性时变调节。使用Lax-Wendroff数值方案获得解决方案，该方案允许旋转破碎孔和跳跃形成并保持。根据障碍物的高度，障碍物上游的流动被发现是完全阻塞、部分阻塞（和液压控制）或畅通无阻的。部分堵塞是通过激发非线性开尔文波的组合来实现的，其中一些波变陡成界面冲击。找到了Kelvin波的Riemann不变量，讨论了激波的质量、动量和位涡的跳跃条件。激波被Rossby变形尺度的分散区域所包围，并且通过流体的位涡以与沿断裂线沿着的能量耗散的微分速率成比例的速率改变。对于初始一致位涡的特殊情况，渐近状态被发现作为初始条件的函数。
The nonlinear time-dependent adjustment of a homogeneous rotating-channel flow to the sudden obtrusion of an obstacle is studied. Solutions are obtained using a Lax–Wendroff numerical scheme which allows rotating breaking bores and jumps to form and be maintained. The flow upstream of the obstacle is found to be completely blocked, partially blocked (and hydraulically controlled), or unobstructed depending upon the height of the obstacle. Partial blockage is accomplished through the excitation of a combination of nonlinear Kelvin waves, some of which steepen into interfacial shocks. Riemann invariants for the Kelvin waves are found, and jump conditions on mass, momentum and potential vorticity for the shocks are discussed. The shocks are surrounded by dispersive regions of Rossby deformation scale, and the potential vorticity of passing fluid is altered at a rate proportional to the differential rate of energy dissipation along the line of breakage. For the special case of initially uniform potential vorticity the asymptotic state is found as a function of the initial conditions.