Viswanathan Shri H, Martinez Daniel M, Bartels Lyle, Guddanti Sai S, Rykaczewski Konrad
School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA.
Julie Ann Wrigley Global Futures Laboratory, Arizona State University, Tempe, AZ, 85287, USA.
Int J Biometeorol. 2023 May;67(5):865-873. doi: 10.1007/s00484-023-02461-z. Epub 2023 Apr 3.
Predicting human thermal comfort and safety requires quantitative knowledge of the convective heat transfer between the body and its surrounding. So far, convective heat transfer coefficient correlations have been based only upon measurements or simulations of the average body shape of an adult. To address this knowledge gap, here we quantify the impact of adult human body shape on forced convection. To do this, we generated fifty three-dimensional human body meshes covering 1st to 99th percentile variation in height and body mass index (BMI) of the USA adult population. We developed a coupled turbulent flow and convective heat transfer simulation and benchmarked it in the 0.5 to 2.5 m·s air speed range against prior literature. We computed the overall heat transfer coefficients, h, for the manikins for representative airflow with 2 m·s uniform speed and 5% turbulence intensity. We found that h varied only between 19.9 and 23.2 W·m K. Within this small range, the height of the manikins had negligible impact while an increase in the BMI led to a nearly linear decrease of the h. Evaluation of the local coefficients revealed that those also nearly linearly decreased with BMI, which correlated to an inversely proportional local area (i.e., cross-sectional dimension) increase. Since even the most considerable difference that exists between 1st and 99th percentile BMI manikins is less than 15% of h of the average manikin, it can be concluded that the impact of the human body shape on the convective heat transfer is minor.
预测人体的热舒适度和安全性需要了解人体与其周围环境之间对流热传递的定量知识。到目前为止，对流换热系数的相关性仅基于对成年人平均体型的测量或模拟。为了填补这一知识空白，我们在此量化成人体型对强制对流的影响。为此，我们生成了53个三维人体网格，涵盖了美国成年人群身高和体重指数（BMI）从第1百分位数到第99百分位数的变化。我们开发了一个耦合湍流和对流换热的模拟程序，并在0.5至2.5米/秒的风速范围内与先前的文献进行了基准测试。我们计算了具有2米/秒均匀速度和5%湍流强度的代表性气流作用下人体模型的总传热系数h。我们发现h仅在19.9至23.2瓦/（平方米·开尔文）之间变化。在这个小范围内，人体模型的高度影响可忽略不计，而BMI的增加导致h几乎呈线性下降。局部系数的评估表明，这些系数也几乎随BMI呈线性下降，这与局部面积（即横截面尺寸）成反比增加相关。由于即使第1百分位数和第99百分位数BMI人体模型之间存在的最大差异也小于平均人体模型h的15%，因此可以得出结论，人体形状对对流热传递的影响较小。
