Aerodynamics of Ski Jumping

Virmavirta, Mikko

doi:10.1007/978-1-4939-3020-3_6

Cited by 12 publications

(9 citation statements)

References 32 publications

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“…1–3 Jumping-skis interact with diverse physical conditions during the event. Specifically, jumping-skis are affected by a frictional force with the track during the in-run phase, 4 a jumping force of the skier during the take-off phase, 5 lift and drag forces during take-off and flight phases, 6–8 and shock during the landing phase. 1–3 In each phase, ski characteristics act differently on the ski.…”

Section: Introductionmentioning

confidence: 99%

Quantification and design of jumping-ski characteristics

Gim

Jeon

Kim

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part P:

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Elastic and dynamic characteristics of jumping-skis affect ski performance at all four ski jumping phases. Compared with the number of studies on alpine-skis, there have been few studies on the characteristics of jumping-skis. This article identifies design parameters that have the most influence on jumping-ski characteristics. To identify the elastic and dynamic characteristics of jumping-skis, previous research and testing methods for alpine-skis were modified. Spring constants and bending stiffness distributions for three jumping-skis were measured. Natural frequencies, modal shapes, and damping ratios were also measured. From these results, the bending stiffness distribution was identified as a more elastic characteristic of jumping-skis than the spring constant. The natural frequency and damping ratio were selected as the relevant dynamic characteristics. To determine the effective design parameter for elastic and dynamic characteristics of jumping-skis, a jumping-ski was modeled by finite element method, and the inner structures and material properties of components of a jumping-ski were measured and analyzed. By comparing the simulation with actual test results, the reliability of the finite element method simulation was verified. The geometrical feature of the ski thickness profile is the most significant design parameter for elastic characteristics of jumping-skis. A mechanical property of the face material and wood at the sidewall is a highly influencing design parameter for dynamic characteristics of jumping-skis.

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Section: Introductionmentioning

confidence: 99%

Quantification and design of jumping-ski characteristics

Gim

Jeon

Kim

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part P:

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“…In other words, Jump 1 showed a

m s −1 better performance regarding in-run speed. This is a substantial difference, since a difference in in-run speed at take-off of ∼

m s −1 can increase the jump distance by 3.8–

approximately, depending on hill size and wind conditions [ 51 , 52 ].…”

Section: Results and Discussionmentioning

confidence: 99%

Performance Analysis in Ski Jumping with a Differential Global Navigation Satellite System and Video-Based Pose Estimation

Elfmark

Ettema

Groos

et al. 2021

Sensors

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This study investigated the explanatory power of a sensor fusion of two complementary methods to explain performance and its underlying mechanisms in ski jumping. A differential Global Navigation Satellite System (dGNSS) and a markerless video-based pose estimation system (PosEst) were used to measure the kinematics and kinetics from the start of the in-run to the landing. The study had two aims; firstly, the agreement between the two methods was assessed using 16 jumps by athletes of national level from 5 m before the take-off to 20 m after, where the methods had spatial overlap. The comparison revealed a good agreement from 5 m after the take-off, within the uncertainty of the dGNSS (±0.05m). The second part of the study served as a proof of concept of the sensor fusion application, by showcasing the type of performance analysis the systems allows. Two ski jumps by the same ski jumper, with comparable external conditions, were chosen for the case study. The dGNSS was used to analyse the in-run and flight phase, while the PosEst system was used to analyse the take-off and the early flight phase. The proof-of-concept study showed that the methods are suitable to track the kinematic and kinetic characteristics that determine performance in ski jumping and their usability in both research and practice.

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“…Women mainly compete in NH (61–77% of competitions in the two previous seasons) while men almost exclusively (>90% of competitions) compete in LH and SF. Comparing performance of men and women in ski jumping are complex as women usually start from higher start gates to achieve a higher take-off speed, and the take-off speed and jump distance are closely related ( 11 ). Hence, to assess women’s performance, and compare with men, one needs to adjust distance for speed and wind conditions.…”

Section: Introductionmentioning

confidence: 99%

Performance and jump-to-jump development in the first female ski flying competition in history

Elfmark,

Sandbakk,

Brevig

et al. 2024

Front. Sports Act. Living

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In 2023, for the first time in history, the international ski and snowboard federation (FIS) arranged an official ski flying competition where the 15 highest ranked women were allowed to participate. This study investigated jump-to-jump performance development in female ski flying, with men’s results used as reference data. Official FIS data from all six jumps of women were evaluated together with the eight jumps by men. Performance was evaluated by a score, where the distance points compensated by wind were divided by take-off speed, enabling performance to be evaluated across jumps and sexes. Women improved performance by 96% from the first to the sixth jump, with two major leaps; from the first to the second jump and from the first to the second day. In contrast, men mainly improved from training to competition. The best women had performance scores equivalent to the 10–20 best ranked men and the sex-difference between the top 3 athletes was 26.2%. This difference was thereafter compared to similar results in the normal and large hill World championship in Planica 2023, in which sex-differences between the top 3 were 8.6% and 14.6% in normal and large hill. This historical competition showed the importance of gaining practical experience with ski flying on performance, exemplified by the large improvement of female athletes. This, together with the enlarge sex-differences in large compared to normal hills, indicates that female ski jumpers have a particularly large improvement-potential in ski flying and must gain specific experience on this through traning and competitions.

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Aerodynamics of Ski Jumping

Cited by 12 publications

References 32 publications

Quantification and design of jumping-ski characteristics

Quantification and design of jumping-ski characteristics

Performance Analysis in Ski Jumping with a Differential Global Navigation Satellite System and Video-Based Pose Estimation

Performance and jump-to-jump development in the first female ski flying competition in history

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