The Experiment And Numerical Simulation Of The Flame Spread In Tubes With Porous Material

The combustion and blast is a attentive issue for all human being. How to utilize it and prevent the lose is an urgent puzzle for all scientist. The main two measures to restrain the blast and flame at present are to destroy the dynamic character of blast and restrain the velocity of flame. And the two measures have effect and relation with each other. Investigating the spread mechanism and discussing the new measures of restraining the blast not only can provide theories and references for the task of restraining the blast, but also is important for the security of task and safety of human life. According to this point, this paper's main work is as follows:(1) Investigate the mechanism of blast and flame spreading. Study the math model and boundary condition. Simplify the physics model, prepare for the experiment and simulation .(2) Firstly, simulate the flame spread in the empty duct. Analyze the theory of blast, ascertain the effective length of absorbing section.(3) Establish the physic model of duct with absorbing section, and then simulate it. Find that with the length increasing of absorbing section, the pressure decrease after the absorbing section. It indicates that the restrain ratio to blast is increasing. The velocity of the flame also decreases. When the increase to some extend, the effect is inconspicuous.(4) In the simulation, with the increase of absorbing section's thickness, the pressure of blast decrease. And to some extent, the effect of restraining is more and more inconspicuous. The velocity after the absorbing section is firstly down and then up, so the absorbing section has a most appropriate thickness.(5) The experiment studies the effect of restraining difference with different length of absorbing section. With the absorbing section's length increasing , the velocity and pressure of blast all decrease.(6) The experiment studies the effect of restraining difference with different thickness of absorbing section. When the absorbing section is short, with the increase of absorbing section, the pressure and velocity is down and then up. It has a most appropriate thickness. When the length is to some extend , the pressure and velocity all decreased.