风速与风向对人体热交换影响的CFD仿真模拟

Computational fluid dynamics numerical simulation of the heat transfer for the human body under various wind velocities and wind directions

为了提升灾害环境中人体热损伤评估精度并保障应急救援人员的生命安全,首先将暖体假人进行三维激光扫描得到数值假人,并按照人体生理构造将其划分为20个区块,通过ICEM软件建立气候室,设置0°~180°的风向;然后通过FLUENT软件计算得到0.2~5.0 m/s风速时的人体显热换热量和辐射换热量,在此基础上求得对流换热量;最后将模拟结果与文献中数据进行对比验证,并分析不同风速与风向对人体热交换的影响。结果表明:提出的计算流体动力学(CFD)仿真模拟方法可有效模拟人体不同部位的换热量;风速的增加会促进人体与环境之间的热交换,当风速从0.2 m/s增加到5.0 m/s时,人体整体对流换热量从56 W/m^(2)增加到360 W/m^(2);人体表面局部部位之间对流换热量有明显的差异,其中四肢部位与环境之间的热交换受风速影响更为明显;风向对人体整体对流换热几乎没有影响,但躯干部位对流换热量受风向的影响较大;在非对称风向(45°、90°、135°)下,人体对流换热量呈现非对称式分布。本研究可为人员安全评估、极端环境下人体热反应建模、防护装备研发等提供基础数据。

In order to improve the accuracy of human thermal damage assessment in a disaster environment and ensure the safety of emergency rescue workers,firstly,a 20-zone computational thermal manikin was constructed using a three-dimensional body scanning technique according to the physiological structure of the human body.Climate chamber and wind directions(0°-180°)were set through ICEM software,and then the sensible heat transfer and radiant heat transfer at 0.2-5.0 m/s air velocities were calculated by FLUENT software.Finally,the convective heat transfer values were calculated through computational fluid dynamics(CFD)simulation and validated against the measurement and simulation results in the literature,and the influence of different wind velocities and wind directions on the human heat exchange was analyzed.The results show that the heat transfer between the human body and the environment is promoted with the increase of air velocity.When the air velocity increases from O.2 to 5.O m/s,the whole-body convective heat transfer of the human body increases from 56 W/m^(2)to 360 W/m^(2).It is found that the large differences in convective heat transfer between the local body,and the heat transfer between the limbs and the environment are more obviously affected by air velocity.In addition,the wind direction has little effect on the whole-body convective heat transfer but significantly influences the trunk part.Asymmetric wind direction(45°,90°,135°)causes the distribution of convective heat flux asymmetrically.This study can offer basic data for personnel safety assessment,human thermal reaction modeling,and protective equipment research and development.