Numerical investigation of the convective heat transfer coefficient for a sleeping infant in a ventilation room

Abstract

This study aimed to investigate the influence of wind speed and direction on the convective heat transfer from a sleeping infant in different postures. A computational fluid dynamics (CFD) model of a virtual infant manikin with realistic dimensions was developed to obtain the convective heat transfer coefficient (hc) at the body surface and the airflow and temperature distributions. The numerical model was validated beforehand using experimental data collected from infant thermal manikin experiments. The simulation results revealed that the infant's whole-body hc increased from 4.00 to 15.73 W/m2·K when wind speed varied from 0.12 to 1 m/s. Infants lost heat more quickly than adults under ventilation, with about 2 W/m2·K higher hc than adults in still air, and the discrepancy widened as the wind speed increased. Wind from the floor generated the highest hc, approximately 66.4% greater than the wind from the feet at 1 m/s wind speed. Considering the wind from the feet caused the most evenly distributed hc, ventilation equipment was suggested to be placed on the side of the infant's feet to reduce local discomfort. Based on the simulation results, empirical models of hc were developed, which lay a solid theoretical foundation for further study on the interaction between infants and environments.