Effect of movement on convection and ventilation in a skin-clothing-environment system

An analytical clothing model is developed to consider the effect of body movement on heat transfer. This model quantifies the impact of forced convection in an enclosed air layer and the effect of ventilation (through fabric pores and ensemble openings) on clothing insulation. The internal air speed (inside an enclosed air layer) caused by human movement is used to calculate the internal forced convective heat transfer coefficient. The model is validated for various combinations of walking speeds, ambient air speeds, and clothing fits. A validation study covering 15 experimental cases compares the local heat transfer coefficients for different parts of the body and for the entire body. These validation cases consist of standing (0 m/s) and two walking speeds (0.27 m/s, and 0.69 m/s), three ambient air speeds: still air (0.17 m/s), 1 m/s and 2 m/s, and three clothing ensembles with different designs. All the experiments were performed on an agile thermal manikin. The average relative error in simulated whole body heat flux was 11%. The presented model has ability to simulate heat transfer with high spatial resolution such as individual body segment, which is the major advantage over existing models.

Automated summary

An analytical clothing model was developed to consider the impact of body movement on heat transfer, quantifying forced convection in an enclosed air layer and ventilation effects on clothing insulation. The model was validated through experimental cases, demonstrating the ability to simulate heat transfer with high spatial resolution.