An investigation into the thermal comfort of a conceptual helmet model using finite element analysis and 3D computational fluid dynamics

A common reason for the reluctance to wear protective headgear during different sports activities like skating or biking is the thermal discomfort to the user caused by heat accumulation within the helmet. A review of existing literature revealed the potential to improve thermal comfort of helmets through convective heat transfer, most often achieved through passive ventilation. This paper aims to investigate areas of high heat concentration in the helmet and examine the effect of various hole configurations on the ventilation performance within the helmet. The thermal comfort properties of skate-style helmets are investigated using computational analysis in the form of finite element analysis and 3D computational fluid dynamics. In order to identify areas of naturally high heat concentrations inside the helmet, a baseline conceptual helmet was generated in Solid Works and a finite element analysis was undertaken in the form of a steady-state thermal study in ANSYS Workbench. Next, a 3D computational fluid dynamics investigation was performed on a range of concept designs developed from the baseline model, representing different hole configurations for three general hole locations front, back and side. The best performing concept designs were then combined into a single model and tested. Flow speeds were measured at set probe points for four individual cross-sections for all the test concept designs. Using the collected data, the ventilation performance of the various concept designs was discussed relative to the baseline model and justified. The computational studies revealed trends between the general hole locations and the local ventilation efficiency, as well as differences between the individual concepts tested for each location. Key findings include holes at the rear being the most beneficial to overall helmet ventilation when compared to front and side holes. Furthermore, all hole locations were found to predominantly affect the flow speeds in the central and upper frontal regions of the helmet, with little impact on the parietal and occipital lobe regions. The best hole configurations were found to be three holes, one hole and two holes for the front, back and side locations respectively. It was shown that combining the strongest individual concept designs does not necessarily lead to a superior helmet design in terms of ventilation performance.