The Characteristics Research Of Smoke Flow In Longitudinal Ventilation Fire Tunnel

The smoke and heat is the main reason for the injured in a long tunnel fire. At present thetunnel ventilation mainly use the longitudinal ventilation with the flow from one end to theother end, and the research focuses on the critical and its influencing factors, the fire plume’scharacteristics, etc. For long tunnel with special smoke exhaust pipe by which the smoke wasexcluded, the smoke characteristics research is relatively few.In this paper, the long tunnel fire smoke experiment with smoke exhaust pipe wasestablished by Froude Number and the characteristics of smoke movement was studied.Numerical simulation was used to complete the experiment. The main research contentsinclude: the value of the confinement velocity, the relationship between the dimensionlessvelocity and the dimensionless fire heat release rate, the distribution of velocity field andtemperature field.It was discovered through the experiment: L/H in T1at confinement velocity was in therange2to4, and T2was down to range1to2;Dimensionless confinement velocity, the totalconfinement velocity and the dimensionless fire heat release rate is a power function relationin a certain range power changes; the smoke can be divided into rapid development part,stable part, a sharp change part and attenuation part; smoke suck a lot of air volume, and itstemperature fell rapidly at first, then rinsed quickly at a certain height.