Sustained gravity currents in a channel
Sustained gravity currents in a channel
复制标题
通道中的持续重力流
DOI：
10.1017/jfm.2016.343
复制
发表时间：
2016
影响因子：
3.7
通讯作者：
Hogg A
中科院分区：
文献类型：
--
作者：
Hogg A
重力驱动的运动所产生的持续恒定源的稠密流体在水平通道中的理论研究，使用浅层模型和直接数值模拟的Navier-Stokes方程，耦合到对流扩散模型的密度场。流入的稠密流体在最初填充通道的较低密度流体下方形成流动层，并且在本研究中计算其传播速度;流出量位于通道的末端。的运动，流体静力平衡的假设下，建模使用两层浅水模型来考虑稠密和上覆的不太稠密的流体的流动。当流体之间的相对密度差很小（Boussinesq制度），治理浅层方程求解使用分析技术。它表明，各种流场模式是可行的，包括那些具有恒定的高度沿着的电流的长度和那些高度连续和不连续变化。在任何情况下实现的解决方案的类型是由源和源弗劳德数发出的无量纲通量的大小确定。可能发生两个重要的现象：流动可能被阻塞，由此由于密度差而导致的过量速度被限制，并且电流的高度可能不超过确定的最大值，并且对于稠密流体来说，也有可能在靠近源的扩展区域中完全取代最初在通道中的所有较低密度流体。这些类型的运动的发病和随后的演变也计算使用分析技术。对于非Boussinesq流，也会出现相同范围的现象;在这种情况下，对模型的解进行数值计算。的Navier-Stokes方程的直接数值模拟的结果也报道了非定常的二维流动，其中有一个密集的流体在通道的一端流入，在另一端流出。这些模拟揭示了详细的力学运动和散装性能进行了比较与预测的浅层模型，以证明良好的协议之间的两个建模策略。
Gravitationally driven motion arising from a sustained constant source of dense fluid in a horizontal channel is investigated theoretically using shallow-layer models and direct numerical simulations of the Navier–Stokes equations, coupled to an advection–diffusion model of the density field. The influxed dense fluid forms a flowing layer underneath the less dense fluid, which initially filled the channel, and in this study its speed of propagation is calculated; the outflux is at the end of the channel. The motion, under the assumption of hydrostatic balance, is modelled using a two-layer shallow-water model to account for the flow of both the dense and the overlying less dense fluids. When the relative density difference between the fluids is small (the Boussinesq regime), the governing shallow-layer equations are solved using analytical techniques. It is demonstrated that a variety of flow-field patterns are feasible, including those with constant height along the length of the current and those where the height varies continuously and discontinuously. The type of solution realised in any scenario is determined by the magnitude of the dimensionless flux issuing from the source and the source Froude number. Two important phenomena may occur: the flow may be choked, whereby the excess velocity due to the density difference is bounded and the height of the current may not exceed a determined maximum value, and it is also possible for the dense fluid to completely displace all of the less dense fluid originally in the channel in an expanding region close to the source. The onset and subsequent evolution of these types of motions are also calculated using analytical techniques. The same range of phenomena occurs for non-Boussinesq flows; in this scenario, the solutions of the model are calculated numerically. The results of direct numerical simulations of the Navier–Stokes equations are also reported for unsteady two-dimensional flows in which there is an inflow of dense fluid at one end of the channel and an outflow at the other end. These simulations reveal the detailed mechanics of the motion and the bulk properties are compared with the predictions of the shallow-layer model to demonstrate good agreement between the two modelling strategies.
登录
查看更多内容
非 Boussinesq 锁交换流模型
影响因子：
3.7
作者：
R. Rotunno;J. Klemp;G. Bryan;D. Muraki
通讯作者：
D. Muraki
由恒定且随时间变化的流入产生的高铼重力流的前沿条件：分析和数值研究
DOI：
--
发表时间：
2013
期刊：
影响因子：
--
作者：
M. Shringarpure;Hyungoo Lee;M. Ungarish;S. Balachandar
通讯作者：
S. Balachandar
基于循环的 Boussinesq 重力流模型
DOI：
--
发表时间：
2013
期刊：
影响因子：
--
作者：
Z. Borden;E. Meiburg
通讯作者：
E. Meiburg
Boussinesq 内孔的基于循环的模型
影响因子：
3.7
作者：
Z. Borden;E. Meiburg
通讯作者：
E. Meiburg
DOI：
--
发表时间：
1991
期刊：
影响因子：
--
作者：
J. Bühler;S. Wright;Younghan Kim
通讯作者：
Younghan Kim