Warm air rising off the warm water is like a pair of conveyor belts fitted with leaky buckets.
温暖的空气从温水中升起,就像一对装有漏水水桶的传送带。
英语百科
Leaky bucket
The leaky bucket is an algorithm that may be used to determine whether some sequence of discrete events conforms to defined limits on their average and peak rate or frequency. It is based on an analogy of how a bucket with a leak will overflow if either the average rate at which water is poured in exceeds the rate at which the bucket leaks, or if more water than the capacity of the bucket is poured in all at once.