烟层 meaning in English

smoke layering
smoke stratification

But emmons observed that at flashover, the hot smoky layer instantly drops down .
但埃蒙斯观察到发生闪燃时，热烟层瞬即下落。
The dirty, still air covers los angeles like a blanket, gradually building up into a thick, smelly, foggy, smokelike layer .
尘污和静止的空气象一个罩子一样覆盖着洛杉矶，逐渐形成了一个浓密的带有臭味的，雾蒙的烟层。
At first , discussing how to establish performance - based code and guide , which aim is to form a whole concept of performance - based design ; guide designer to achieve design , etc . based on this , the author has put forward the concept of performance requirement , fire scenario and forecasting smoke interface , and then tapped out the software ( pb - ascdt ) using high - language of visual basic6 . o and microsoft access2000
在此基础上，提出设计火灾场景、量化性能指标、烟层界面预测等新的观念，以此为性能化设计的依据，并使用visualbasic6 . 0和microsoftaccess2000为开发工具开发中庭烟气控制性能化设计工具软件( pb - ascdt ) 。