蘑菇云

通流

云冠是个涡圈。
大家觉得，这整个蘑菇云结构是怎么产生的那？

于新

高温上升气流和头部受到周围空气阻力及降温后速度减慢的共同作用，在头部周围形成了环形涡旋，就形成了这样的蘑菇云。 对不对 ？  大家继续讨论！

通流

当然是浮力造成的涡。论坛里有人讨论涡到底是怎么形成的。其实，最终都可以追溯到力。流体力学也还是力学吗！

onesupeng

咦，你的冲量理论呢？怎么又演化成力了？

通流

冲量不就是力乘时间吗。没有时间，再大的力也不能起作用啊。我还没这么厉害，能够搞出个冲量理论来。那可是牛顿定律，普朗特的贡献。咱们就只有学习的份。

baroclinic

Rayleigh-Taylor instability

From wiki:

The Rayleigh–Taylor instability, or RT instability (after Lord Rayleigh and G. I. Taylor), is an instability of an interface between two fluids of different densities, which occurs when the lighter fluid is pushing the heavier fluid.[1] [2] This is the case with an interstellar cloud and shock system. The equivalent situation occurs when gravity is acting on two fluids of different density — with the dense fluid above a fluid of lesser density — such as water balancing on light oil.[2]
Consider two completely plane-parallel layers of immiscible fluid, the heavier on top of the light one and both subject to the Earth's gravity. The equilibrium here is unstable to certain perturbations or disturbances. An unstable disturbance will grow and lead to a release of potential energy, as the heavier material moves down under the (effective) gravitational field, and the lighter material is displaced upwards. This was the set-up as studied by Lord Rayleigh.[2] The important insight by G. I. Taylor was, that he realised this situation is equivalent to the situation when the fluids are accelerated (without gravity), with the lighter fluid accelerating into the heavier fluid.[2] This can be experienced, for example, by accelerating a glass of water downward faster than the Earth's gravitational acceleration.[2]
As the instability develops, downward-moving irregularities ('dimples') are quickly magnified into sets of inter-penetrating Rayleigh–Taylor fingers. Therefore the Rayleigh–Taylor instability is sometimes qualified to be a fingering instability.[3] The upward-moving, lighter material is shaped like mushroom caps.[4][5]
This process is evident not only in many terrestrial examples, from salt domes to weather inversions, but also in astrophysics and electrohydrodynamics. RT fingers are especially obvious in the Crab Nebula, in which the expanding pulsar wind nebula powered by the Crab pulsar is sweeping up ejected material from the supernova explosion 1000 years ago.[6]

baroclinic

Hydrodynamics simulation of a single "finger" of the Rayleigh–Taylor instability[9] Note the formation of Kelvin–Helmholtz instabilities, in the second and later snapshots shown (starting initially around the level y = 0). As well as the formation of a "mushroom cap" at a later stage in the third and fourth frame in the sequence.

Mclaren

密度，温差，压差。。。

zｚZＺZｚz

还有一点
举个例子说吧，把个鞭炮放在小石头下面引爆，石头会飞起来
那是什么呢，这和蘑菇云中段的直线有联系吗

我把它理解为，地面对 原子弹爆炸造成的激波的反射和内压膨胀的反弹
它的形状如此笔直，所以在与它形状垂直的地面最有可能是 凶手 ！！！

（噢，好吧，我承认我柯南看多了 Orz。。。。。。。。。。。）

invader

烟圈！！！