Thermal Energy Removal From a Human Eye for Different Environmental Conditions—A Computational Fluid Dynamics Study Using a Full-Scale Mannequin

Abstract

Abstract. The eye is a critical organ of the human body, and its physiology can be influenced by ambient air temperature and airflow velocity. In this study, a three-dimensional computational model of airflow around a full-scale mannequin and the flow inside the eye is developed and used to evaluate thermal energy removal from the mannequin's eyes due to natural and forced convection under various environmental conditions. For natural convection, it was assumed that the movement of the surrounding air was only due to the buoyancy effect in the body's thermal plume. Uniform air velocity and temperature far from the mannequin were assumed for combined natural and forced convection. For simulating the velocity and temperature variation, equations of continuity, momentum, energy, and the turbulence transport model were numerically solved. The results for specific conditions were compared with the available experimental data reported in the literature, and the acceptable agreement was found. The validated computation model was used for several simulations of wind velocities and air temperatures. It was found that the eye surface temperature variation predicted by the present model is closer to the experimental data than that of earlier numerical studies for detached eyeballs, which used a constant convective heat transfer coefficient. The present results showed that the convective heat transfer coefficient over an eye surface depends strongly on the airflow velocity and temperature near the head.