V. On the origin of windings of rivers in alluvial plains, with remarks on the flow of water round bends in pipes
V. On the origin of windings of rivers in alluvial plains, with remarks on the flow of water round bends in pipes
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DOI：
10.1098/rspl.1876.0004
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发表时间：
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影响因子：
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通讯作者：
J. Thomson
中科院分区：
文献类型：
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作者：
J. Thomson
关于流经冲积平原的河流的弯曲的起源，人们通常有一个粗略的概念，即当有一个弯曲以任何方式开始时，水只是在弯曲处冲到河流的外河岸上，因此冲走了河岸，并允许在内河岸上发生沉积，从而使弯曲度增加。但是在这一点上，他们忽略了一个不为人所知的水力学原理，即如果我们把下游看作是理想流体，那么，一条水流沿沿着一条直道流动，然后进入一条弯道，那么，它必定是以沿着外侧的速度减小，而以沿着内侧的速度增大。鉴于这一原则，几年前我就提出了这样一个问题：为什么内层的磨损不比外层的多？根据一般经验和观察，我们知道，事实上，外层的磨损是会消失的，而沉积物往往是沿着内层的。这是如何产生的呢？1872年，我想到了这个解释，主要如下：
In respect to the origin of the windings of rivers flowing through alluvial plains, people have usually taken the rough notion that when there is a bend in any way commenced, the water just rushes out against the outer bank of the river at the bend, and so washes that bank away, and allows deposition to occur on the inner bank, and thus makes the sinuosity increase. But in this they overlook the hydraulic principle, not generally known, that a stream flowing along a straight channel and thence into a curve must flow with a diminished velocity along the outer bank, and an increased velocity along the inner bank, if we regard the low as that of a perfect fluid. In view of this principle, the question arose to me some years ago:— Why does not the inner bank wear away more than the outer one? We know by general experience and observation that in fact the outer one does wear away, and that deposits are often made along the inner one. How does this arise? The explanation occurred to me in the year 1872, mainly as follows:—