A comparative experimental study of the thermal properties of cricket helmets

摘要

Extensive research into heat transfer properties of protective helmets using thermal manikin heads or other headforms has been conducted to date. However, most studies have focused on bicycle, motorcycle and industrial helmets, while literature on cricket helmets remains lacking. This study aimed to evaluate the thermal properties of selected, commercially available cricket helmets, which are widely used in recreational and international cricket games. Comprehensive experiments were conducted in controlled laboratory conditions. The effects of wind were not considered as the wind speed was maintained at <0.8 ± 0.1 ms~(-1). The average temperature at eight selected locations beneath the helmet shell and liner were continuously measured using k-type thermocouples. Five commercially available cricket helmets were used in this study. The research identified high temperature increments at the frontal and parietal regions of the tested helmets, which indicates that these regions have poor heat dissipation due to lack of ventilation outlets in existing designs. Two forms of heat transfer were investigated: convection and radiation. The total heat transfer from the headform to the surrounding environment decreased by 13-17% when wearing a cricket helmet. Based on the experimental results, several design strategies and features are recommended in order to improve the air ventilation in critical regions of the helmet. Relevance to industry: Protective helmets currently used in cricket offer sufficient protection to players against impact. Thermal discomfort is one of the cricket players' main complaints when wearing protective helmets. This article identifies the main hot spots in cricket helmets and presents design strategies for improving heat dissipation and thermal comfort. Some design attributes of industrial helmets of relevance to thermal comfort are discussed in this context.