Research on heat flow change in outdoor service shirt based on FEM numerical simulation

Purpose The purpose of this paper is to construct a human body-garment-environment integrated model in CFD simulation to evaluate the heat flow change in an outdoor service shirt. The proposed model as well as the method can be used to analyze the undergarment microenvironment and to predict the thermal comfort of the garment. Design/methodology/approach In this paper, the clothing fabric in the climate chamber was considered as a classical porous medium model, and the heat transfer mechanism in the microenvironment of a thermal manikin wearing a single-layer long-sleeved outdoor service shirt was investigated by using the thermostatic method under different levels of wind environments. The human body model consistent with the thermal manikin and the relevant clothing model of a shirt with the real size is established by using CLO3D software. Heat transfer and fluid change in a single-layer shirt subjected to the wind were simulated in an FEM software. The mathematical model of heat transfer and fluid changes in a single-layer shirt subjected to wind was established. Findings By using the physical property parameters of the real fabric materials, experiments were conducted with different wind speeds, combined with the simulation function of the climate chamber using the thermostatic method. Finally, numerical simulation results were analyzed and compared to the results of a real thermal manikin to validate the feasibility of the simulation of the characteristics of the change of heat flow under the clothing of the single-layer outdoor service shirts in FLUENT. The relative error between the simulation results and the actual results of the space temperature in each region under the garment using this numerical simulation technique was explored, with an error range of <6.67%, verifying the feasibility of the simulation model. Originality/value A human body-garment-environment integrated model in CFD simulation was established to evaluate the heat flow change in a typical shirt. The detailed parameters of the shirt fabric were determined by testing all aspects of the garment fabric. The actual porosity of the sample outdoor service shirt was determined by mercuric pressure, and the parameters obtained were used to create a closer simulation of the material data. A real-size human body model and the relevant garment model were created in the simulation process. The method provided a feasible numerical way to evaluate and predict heat transfer and the microenvironment of the garment and to produce robust and reliable simulation performance.