The Ratio of Fuel and Air under Natural Ventilation Obtained through the Same Opening

It is very difficult to calculate the inlet air volume and the outlet smoke volume under natural ventilation in a very low flow speed through the same opening. The way that the smoke yields and transportation is analyzed on the basis of the burning state reflected by the parameter ф in the compartment of fire origin is easy to extend to the real building without the certain limitation of the building structure such as the opening height and the geometry prototype. The ratio ф is obtained through temperature measuring in this paper with the continuous adjustment of the neutral plane by iteration.