基于CFAST和FDS的舰船舱室火灾蔓延特性对比研究

Comparative study on the fire spread characteristics under cabin fire by using CFAST and FDS

为了研究舰船舱室火灾蔓延规律并分析不同理论模型的适用性,分别基于双区域模型的CFAST软件和大涡模拟的FDS软件构建了舱段火灾场景模型,开展了舱室火灾数值模拟,详细分析了火灾温度分布规律和烟气蔓延特性,进而对2种数值方法的求解差异和适用性进行分析。结果表明,CFAST计算效率高但无法考虑物体真实燃烧反应,同时对于远源场烟气的垂直流动模拟较差,适用于多工况单层舱室火灾特性快速预报,可用于船舶消防系统的初步设计;FDS采用数值方法直接求解受火灾浮力驱动的低马赫数流动的Navier-Stokes方程,计算精度高,但效率较低,适用于船舶详细设计阶段的消防系统设计和人员疏散方案制定。

In order to study the law of ship fire spread and analyze the applicability of different theoretical models,a multi-compartment fire scene model was constructed based on the CFAST software of the two-region model and the FDS software of the large eddy simulation,and the numerical simulation of the cabin fire was carried out.The characteristics of fire spread were studied in detail,and the difference and applicability of the two numerical methods were analyzed.The results show that CFAST has high computational efficiency,but the actual combustion reaction of combustible matter couldn't be considered effectively,furthermore,the simulation of far-field vertical flow is invalid.Therefore,it is suitable for rapid prediction of fire characteristics of single-layer cabin under multiple working conditions and can be used for preliminary design of ship fire protection system.Meanwhile,FDS uses numerical methods to directly solve the Navier-Stokes equations of low Mach number flow driven by fire buoyancy.It has high calculation accuracy but low efficiency and is suitable for fire protection system design and evacuation plan formulation in the detailed design stage of ships.