Helmet position, ventilation holes and drag in cycling

Underwood, L.; Jermy, Mark; Eloi, P.; Cornillon, G.

doi:10.1007/s12283-015-0181-7

Cited by 7 publications

(14 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Averaging all sensors to obtain an indication of overall thermal comfort (the left-most group in Figure 7), the best configurations tested were the Figure 8 compares the temperature differences (averaged over all holes) to the aerodynamic drag measured in the work by Underwood et al 9 Only those cases for which drag was measured are shown. The error bars for temperature ( + /20.1°C to 0.3°C) are smaller than the symbols.…”

Section: Resultsmentioning

confidence: 99%

“…The manufacture of the helmet is described in the work by Underwood et al 9 and the finished item is shown in Figure 2. It roughly conforms to the external shape of the Bell Meteor II.…”

Section: Equipment and Methodsmentioning

confidence: 99%

“…The helmet was held in place with a commercial chinstrap. It was mounted with the mannequin neck vertical (head or neck angle of 0°) and a tip-of-nose-to-brow-of-helmet distance of 75 mm (measurements as defined by Underwood et al 9 ).…”

Section: Equipment and Methodsmentioning

confidence: 99%

“…Aerodynamic drag area (CdA) was measured using the methods described in the work by Underwood et al, 9 including correction for the drag of the neck angle adjustment bracket. The total error for drag area measurements was 60.0006 m 2 (from repeatability tests on the same day and different days).…”

Section: Equipment and Methodsmentioning

confidence: 99%

“…A previous study by our group explored the relationship between ventilation holes and aerodynamic drag. 9 A custom-built helmet with holes which could be opened or closed was used. The head angle and nose-to-helmet distance were more important in determining drag area than the number or position of ventilation holes, with only a slight reduction in aerodynamic drag for a helmet with no ventilation holes compared to multiple, large holes.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Thermal comfort and drag of a streamlined cycling helmet as a function of ventilation hole placement

Underwood

Vircondelet

Jermy

2017

Proceedings of the Institution of Mechanical Engineers, Part P:

View full text Add to dashboard Cite

The ideal cycling helmet allows rapid heat loss from the head with minimum aerodynamic drag. The position and size of ventilation holes affect both heat loss and drag. An aero helmet with reconfigurable ventilation holes was mounted on a heated mannequin head in a wind tunnel at 16.7 m/s (60 km/h). Temperatures on the surface of the head, and the drag area (CdA), were measured for a number of different ventilation hole configurations. Surface temperature was lower immediately underneath the open ventilation holes, whatever configuration of open holes was tested. The average surface temperature was taken as a proxy for thermal comfort. Surprisingly, there was very little difference in average surface temperature with all holes open compared to no holes open, though the latter has lower drag. The lowest average surface temperatures were obtained when either the rearmost holes only were open or when only holes at the top of the helmet, halfway between the front and rear of the helmet, were open (referred to as 'middle holes open'). Besides being effective in dissipating heat, these middle holes open configuration produced lower drag than the rear holes open configuration. However, we note from a previous study with this helmet that drag is more strongly affected by neck angle and how the helmet is fitted, than by the ventilation holes.

show abstract

Section: Resultsmentioning

confidence: 99%

“…The manufacture of the helmet is described in the work by Underwood et al 9 and the finished item is shown in Figure 2. It roughly conforms to the external shape of the Bell Meteor II.…”

Section: Equipment and Methodsmentioning

confidence: 99%

Section: Equipment and Methodsmentioning

confidence: 99%

Section: Equipment and Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations