闪火热灾害环境向着装人体的三维瞬态传热模拟及皮肤烧伤预测

Flash fire hazard poses mortal threat to the public and first responders. In order to equip people properly with fire protective clothing and provide reliable thermal protection, it is urgent to conduct fundamental research on heat transfer mechanism from a flash fire environment to clothed human body. Breaking through the traditional method which uses a simplified one dimensional heat transfer model, three dimensional heat transfer analysis and skin burn prediction should be investigated based on actual human skin properties..This proposed project uses a reverse engineering method to numerically redevelop flame manikin in a flash fire environment. To be specific, three dimensional geometry models of fire protective clothing, air gap and human body during a flash fire exposure are developed. In order to clarify heat transfer from flash fire to clothed human skin with uneven distributed air gaps, a three-dimensional transient heat transfer model is developed and solved using computational fluid dynamics methods. Simultaneously, flash fire exposure tests of clothing are used to validate and optimize this model. The mechanism of heat transfer in ‘flash fire-protective clothing-air gap-human skin’ system will be revealed, as well as the influence of three dimensional geometrical characters on heat transfer in human skin and on skin burn. .This proposed project will finally get the prediction diagram of a precise distribution of burn injury for covered human skin, so that the thermal protective performance of fire protective clothing could be characterized quantitatively. This will provide quantitative basis for development of protective clothing material and the design of involved parameters, as well as meet the needs of key technologies of fire protective ensembles for public safety prevention and control.

闪火轰燃对公众和救援人员造成致命威胁，为科学装备防火服装以发挥可靠的热防护作用，当前迫切需要开展闪火热灾害环境中着装人体传热机制的基础研究，突破长期沿用的一维传热简化模型不能全面反映热危害水平的瓶颈，并基于真实皮肤属性进行三维传热分析和烧伤预测。.本项目将逆向工程技术应用于火场燃烧假人的数值重构，建立闪火热灾害环境中防火服装、衣下空间及人体的三维几何网格模型。针对闪火轰燃向具有不规则衣下空间着装状态的人体皮肤传热，利用计算流体动力学方法构建并求解三维瞬态模型，同时通过火场燃烧假人着装实验进行客观验证及优化。揭示“闪火—服装—衣下空间—皮肤”系统的三维瞬态传热机制，以及皮肤三维形态对其内层传热及烧伤的影响规律。.本项目将绘制防火服装覆盖下人体皮肤烧伤度精确分布的预测图谱，量化表征防火服的热防护水平，成为防火服装材料研发及构成参数化设计的定量依据，满足我国公共安全防治对防火装备关键技术的需要。

依托“东华火人”着装闪火轰燃物理实验平台，基于计算流体动力学、传热传质学基本原理及逆向工程技术等多学科交叉，实现了高热流密度闪火环境中，大空间、全尺度燃烧、流动及传热的仿真控制，以及着装人体热传递、衣下皮肤烧伤过程的三维瞬态数值模拟。建立了高温闪火环境中服装热防护性能数值模拟测试平台，可用于模拟各类复杂火场环境，预测火场中人体的烧伤危害程度及安全逃离时间，为高性能热防护服装的研制开发提供数据支持。.利用CFD技术进行了燃烧室内贴体服装、三维简化服装、均匀着装三种理想着装状态下的三维瞬态传热模拟及热防护性能测评。对包含不规则衣下空间的实际着装情况，实现了全尺度、高精度三维几何建模及闪火热暴露实验的三维瞬态传热CFD模拟。在此基础上，开展了闪火热暴露环境中不同风速条件、不同热流密度等级、不同热暴露时间、服装参数变化等情况下基于数值假人的人体热防护模拟研究。定量分析了防护服由于储存热释放导致的危害效应，定量评价了消防服用织物热暴露时间和冷却时间对其热防护程度的影响。针对闪火环境中不同材料假人表面的热响应规律的模拟研究，从三维角度揭示了燃烧假人表面的热流传感器和真实人体皮肤之间的热响应差异机制。.通过防火服装三维瞬态传热的动力学仿真，全面解析了服装织物层及衣下空间的传热机理。同时发展了一种考虑实际人体皮肤厚度分布的烧伤预测建模方法，实现了对局部烧伤等级的精准预测。通过利用烧伤等级分布预测图谱量化表征防火服的热防护水平，获取皮肤烧伤等级分布随时间的演变规律，成为防护材料研发及服装构成参数化设计的定量依据。研究成果构建了“燃烧模拟-性能评估-功能设计-实验验证”的热防护性能预测及改良开发新体系，为人体热防护服装系统研究提供理论基础和模拟实验平台。在学术期刊共发表论文30篇，其中SCI收录25篇，SSCI收录1篇，EI收录4篇；获授权发明专利4项；培养6名博士研究生、2名硕士研究生。