Modeling on the Contentious Backdraft in a Low - Ventilated Condition

Abstract

This paper describes the results of the simulation of backdraft with the one-zone modeling. The one-dimensional pyrolysis model was added to the one-zone model in order to consider supplying pyrolysate from a flammable wall. Also the heat generation model with first-order Arrhenius' equation was added to consider the heat generation due to the oxidizing pyrolysate after a self-extinction. The temperature peak was shown in the result of simulation. This temperature peak was consequence of a backdraft. Then, the backdraft simulation was carried out in several opening parameters and types of opening. In AH^1/2=0. 02m^5/2 window type opening case, the backdraft occurs most frequently. In this case, six backdrafts occur. In too large (AH^1/2 > 0.06m^5/2) or too small (AH^1/2 < 0.005m^5/2) opening case, the backdraft does not occur. In the AH^1/2=0.03m^5/2 door type opening case, eight backdrafts occur and in AH^1/2=0.01m^5/2 slot opening case, four backdrafts occur. These results suggested that frequency of backdraft depends on the height of opening, the sill height and the opening parameter, AH^1/2.