So the Joule free expansion involves opening this valve and asking what happens when this gas moves into the other bulb or distributes between the two.

焦耳自由膨胀就是,打开阀门后的过程,气体从一个腔跑到另一个腔,并在它们之间平均分配。

麻省理工公开课 - 热力学与动力学课程节选