剧透

这一集讲的是水力学中的比例模型。之前我们上《流体力学》的时候,清华的泥沙实验室,里面貌似就有一个比例模型。

因为早期计算能力不强,对于水力学的模拟,搭比例模型来仿真是最方便的。

这一集中讲到20世纪30年代,密西西比河一直闹洪灾,比例模型的引入,在抗洪中起了大作用。

生词表

  • [levees]{防洪堤} were [strained]{受到强大压力}
  • this [tragic]{悲惨的} event
  • Herbert Hoover
  • … which [empowered]{授权} the Army Corps of Engineers
  • build [infrastructure]{基础设施} to [corral]{把..赶入畜栏} and [maneuver]{操纵} the river in order to control it.
  • The Army Corps began constructing [crude]{粗糙的,简陋的} models, [mere]{小湖} [ditches]{沟,渠} cut in the [dirt]{泥土} with water flowing through them.
  • [sophisticated]{复杂的}
  • [continental]{美洲殖民地的} United States
  • … [spanning]{跨越…时间/空间} more than 200 [acres]{英亩}
  • predicted which levees would be [overtopped]{超出,高出}
  • especially after the [advent]{出现} of computer modeling
  • Today, it is completely [derelict]{被抛弃的}.
  • leaving a mess of [concrete]{混凝土} and [wire]{金属丝} [mesh]{网状物}.
  • But physical modeling as a practice did not [die off]{相继死掉} with the Mississippi [Basin]{盆地,流域} Model.
  • ERDC has the feel of a Hollywood studio [backlot]{外景场地} —there’s row after row of [hangars]{飞机库} and [warehouses]{仓库}, with engineers zipping between them in trucks and [golf carts]{高尔夫球车}.
  • Stanford Gibson, a senior [hydraulic]{水力学的} engineer for the Army Corps, says we need “a bit of scientific [humility]{谦逊}…some of these processes are outside our reach, or at least outside the reach of our generation.”
  • We may have the equations to understand what is happening at a given scale, but scaling that understanding up to fully capture the [nuances]{细微差别} of water moving through a river is [incredibly]{难以置信地} complex and difficult.