Application of Experimental Measurements in a Wind Tunnel to the Development of a Model for Aerodynamic Drag on Elite Slalom and Giant Slalom Alpine Skiers

Majerič, Matej; Verdel, Nina; Ogrin, Jan; Holmberg, Hans-Christer; Supej, Matej

doi:10.3390/app12020902

Cited by 3 publications

(7 citation statements)

References 18 publications

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“…The findings herein are in good agreement with previous studies. For example, C d A was calculated to be 0.19 m 2 for a fully tucked position at 25 m/s 10 and 0.23 ± 0.03 m 2 for a tucked position at 22.2 m/s wind speed 33 . The slight difference was due to the slightly different posture and human parameters of the prototype of the mannequin.…”

Section: Methodsmentioning

confidence: 99%

Effect of ambient wind on the performance of alpine downhill skier

Zhang

Jia

et al. 2023

Sci Rep

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Alpine skiing, especially alpine downhill, is one of the most extreme winter sports in terms of high-speed and narrow winning margin, and its tracks are always located in mountainous areas with high altitudes and complex ambient wind fields, resulting in a significant impact of ambient wind on the performance and the final ranking of alpine downhill skiers. In the present study, a method based upon the combination of field measurements, wind tunnel tests and kinematic simulations was used to evaluate the effect of ambient wind on the performance of an alpine downhill skier. Considering the effect of ambient wind, a kinematic model of the alpine skier-ski system was established, and the equations of motion for straight gliding and turning were deduced. Then, the Chinese National Alpine Ski Center (CNASC) downhill track was taken as a case study to investigate the effect of ambient wind on the gliding time using the proposed combined evaluation method. Field measurements and wind tunnel tests were performed to identify five critical ambient wind directions of 270°, 292.5°, 315°, 337.5° and 360°. Moreover, the wind speeds and the wind directions for 16 different measurement points of the downhill track were also obtained. The results of the modelling analysis showed that the finish time increased by 19.75% for the ambient wind direction of 270°, whereas the finish time decreased by 1.29% for the ambient wind direction of 360°.

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Section: Methodsmentioning

confidence: 99%

Effect of ambient wind on the performance of alpine downhill skier

Zhang

Jia

et al. 2023

Sci Rep

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Section: Introductionmentioning

confidence: 99%

“…To measure aerodynamic drag in connection with alpine ski racing, several experimental approaches have been developed for both speed [13][14][15] and technical disciplines [5,6,16]. Assessment of the coefficient of aerodynamic drag (C d ) and cross-sectional area (S), as well as C d •S, the product of these two, in wind tunnels have attempted to optimize body posture, showing that height, joint angles, and positioning of the arms and head all influence the aerodynamic drag [5,6,16]. Moreover, C d •S for the technical disciplines ranged from 0.63-0.66 in the high, 0.51-0.55 in the middle, and 0.23-0.24 in the tuck positions, which is generally lower than the corresponding values reported for the speed disciplines (0.15-0.4) [8,13].…”

Section: Introductionmentioning

confidence: 99%

The Contribution of Ski Poles to Aerodynamic Drag in Alpine Skiing

et al. 2023

Self Cite

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The present study was designed to determine the contribution of the cross-sectional area of the ski poles (Sp) to the total aerodynamic drag during alpine skiing. At three different wind speeds in a wind tunnel, 10 skiers assumed typical alpine skiing postures (high, middle, and tuck), and their frontal aerodynamic drag was assessed with a force plate and their cross-sectional area, along with that of their ski poles, determined by interactive image segmentation. The data collected were utilized to examine intra-subject variation in Sp, the effects of Sp on the coefficient of aerodynamic drag (Cd), and the product of Cd and total cross-sectional area (Cd∙S. The major findings were as follows: (i) Sp ranged from 0.0067 (tuck position) to 0.0262 m2 (middle position), contributing 2.2–4.8% of the total cross-sectional area, respectively; (ii) Sp was dependent on wind speed in the high and middle positions; (iii) intra-subject variations ranged from 0.0018 m2 (27.6%) in the tuck position to 0.0072 m2 (30.5%) in the high position; (iv) Sp exerted a likely effect on Cd and Cd∙S. The extensive intra- and inter-skier variability in Sp can account for as much as ~5% of the total frontal cross-sectional area and future investigations on how elite skiers optimize their positioning of the poles in a manner that reduces aerodynamic drag are warranted.

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“…As an example, in the ladies super-G competition at the 2018 Winter Olympics in Pyeongchang, the difference between the gold medal and fifth place was only 0.16s and just 0.01s separated the gold and silver medalist [1]. The aerodynamic drag is one of the most important factors determining performance in the high-speed disciplines Downhill and Super-G [2,3], and is also a performance factor in Giant Slalom [4,5].…”

Section: Introductionmentioning

confidence: 99%

“…In general, one can separate the movements of an alpine skier into three main components; I: Extension/flexion of hip, II: Extension/flexion of knees, and III: Arm movements. The movements of the hip and knees are strongly coupled in terms of maintaining balance, turning and have also been the main focus in aerodynamic research in terms of postural changes linked to drag reduction [2,4,5,7,9]. A straightforward way to reduce the drag in sports aerodynamics is by reducing frontal area, which is effectively achieved by hip flexion, i.e., reduce the frontal area of the torso [10].…”

Section: Introductionmentioning

confidence: 99%

Aerodynamic influence of an alpine skier’s arms

Giljarhus

Reid²,

Liland

et al. 2022

Sports Eng

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Understanding how postural changes in alpine skiing affect the overall aerodynamic drag is highly important for enhancing performance. Although the arm configuration of the athlete can have a significant impact on the overall drag force, this effect is currently less understood. The purpose of this investigation was to examine how the arms of an alpine skier influence the overall drag. Experiments were performed in a wind tunnel for a male and female athlete, and computational fluid dynamics simulations were performed on 3D scans of the athletes. The influence of the arm configurations in three different scenarios are considered; low-tucked, high-tucked, and flight postures. Consistent trends are found for both athletes and between the experiments and simulations. In general, the arms were found to be highly influential of the overall drag, and hence also performance in alpine skiing. For the low-tucked posture, the maximum variation in total drag area depending upon the angle of the underarms is 2.8%, with the lowest drag found with a medium angle of 20$$^\circ $$ ∘ to 25$$^\circ $$ ∘ . For the high-tuck posture, the difference in drag area between a closed and open posture was found to be 17% to 21%. The flight postures showed the highest influence of arm configurations, with a maximum difference in drag area of 64% between the considered postures. These results contribute to the understanding of aerodynamics in alpine skiing, and could be implemented directly in the training of athletes to improve their aerodynamic performance.

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Application of Experimental Measurements in a Wind Tunnel to the Development of a Model for Aerodynamic Drag on Elite Slalom and Giant Slalom Alpine Skiers

Cited by 3 publications

References 18 publications

Effect of ambient wind on the performance of alpine downhill skier

Effect of ambient wind on the performance of alpine downhill skier

The Contribution of Ski Poles to Aerodynamic Drag in Alpine Skiing

Aerodynamic influence of an alpine skier’s arms

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