共查询到19条相似文献，搜索用时 156 毫秒
1.
在划臂过程中手指间隙的变化对游泳推进力的贡献作用的探讨 总被引：4，自引：1，他引：3
狄建 《西安体育学院学报》2003,20(1):71-72,80
依据阻力与速度的平方成正比这一流体动力学基础定律 ,以创新的思维形式提出手指分开划水这种新的划臂技术 ,它的理论基础依据为手掌的阻力系数与手掌对水的有效表面积成一次方函数关系 ,而手掌的阻力系数与手掌的划水速度则为二次方关系。由此可推论 ,手指分开划水可在高速划水过程中增大它的对水表面积 ,而且它的推进力系数则以平方级数增加。 相似文献
2.
从动力学角度,要提高游泳运动员游进的速度,必须减小阻力,增大推动力,使二者最佳结合。本文着重从臂划水的力学进行了分析,提出高肘屈臂划水是最合理的划水技术。 相似文献
3.
使用划水掌可以增加手的表面积，提高在划水过程中手对水的感觉，帮助运动员体会在划水的不同阶段寻找适当的角度。如果使用得当，还有助于神经肌肉的学习，通过反复使用，甚至不戴划水掌时，运动员也将可以很自如地调整划水过程中的角度。 相似文献
4.
利用计算流体力学软件FLUENT对比赛用单人赛艇实船的粘性绕流进行了数值模拟,得到了不同航速下的艇体表面压力和相应的摩擦阻力系数及粘性阻力系数;对不同航速下的摩擦阻力和粘性阻力计算结果与经验公式和实验结果进行了对比,通过比较可以看出利用FLUENT软件能够快速有效地预报赛艇船体的粘性阻力和流场. 相似文献
5.
一、前言在游泳运动中,技术动作直接影响划水推进力的大小。这种力量的大小,不完全取决于迅速地划臂,还与手掌在划水对所取的对水角度有很大关系。这里涉及到两种分力(流体阻力和升力)所组成的合力与手的相互作用问题。虽把目前对这两种受力情况的解释仍然有不同意见,但是这种作用在手、足上的力是客观存在的,而且它必然是 相似文献
6.
目的:讨论一种在赛艇训练中增加训练阻力同时又不影响运动员技术动作的设备,即赛艇阻力器,在不同攻角、不同速度状态下,阻力、压力的变化,阻力与速度之间的关系以及增阻效果分析。方法:运用CFD软件FLUENT 6.2版本进行数值模拟。结果:速度不同,攻角相同状态下的阻力系数是相等的,阻力随速度和攻角的增大而增大,速度变化对阻力板阻力及压力的影响要大于角度的变化所产生的影响,阻力大小与速度的平方成正比,而阻力系数是常数。以155kg和175kg赛艇,阻力板攻角90°,赛艇划行速度5m/s为例,当无风状态时,安装阻力板的155kg赛艇增加的阻力(20.58N)比增加20kg重量(175kg)的阻力值(7.25N)大13.33N,增加的阻力值接近2倍。当顺风风速为3m/s时,阻力板增加的阻力为3.26N,比增加20kg重量的阻力值小3.99N,当逆风风速为3m/s时,阻力板增加的阻力为51.94N,比增加20kg重量增加的阻力值大44.69N,增加的阻力值近6倍多。结论:FLUENT软件对赛艇阻力板阻力计算是准确的,模拟的结果可以应用于具体的实际问题中。90°攻角状态下使用阻力板增加的阻力要优于由于赛艇艇重增加所达到的增阻效果。当处于顺风训练时,风速使阻力板增加的阻力值减小,减弱增阻效果,而逆风训练时,风速使阻力板产生的阻力值增大,加大了增阻效果。因此,采用阻力板训练,可以不改变赛艇的吃水和重心,保证运动员技术的完整性和连贯性,并且增加训练的强度,提高了训练的科学化水平。 相似文献
7.
根据我国八名优秀仰泳运动员比赛速度游的水下技术影片的解析数据,分析了右手划水各时刻的划水速度和划水角度,揭示出我国优秀仰泳运动员的划水效果和划水特征。 相似文献
8.
鞠鑫涛 《体育科技文献通报》2006,14(6):76-77
1.澳中优秀男子自由泳运动员的技术特点对比(1)澳大利亚运动员哈克特的自由泳技术特点。在自由泳中,减少阻力的方法就是尽量向两头伸展,而前交叉技术是伸展的最好选择。哈克特也正是采用这种方法进行训练的。前交叉配合技术是与较长的身体姿势紧密相连的。当身体尽量伸长,并且在每一个动作周期内尽量保持这种较长的身体姿势时,阻力和克服阻力所需要的力量就明显减少。采用适宜的速度游进,身体多数处于侧卧位置,并呈良好的流线型,这种形状就成为“赛艇”形状。如果移臂和划水同时进行,即移臂的手臂与划水的手臂同时经过肩关节时,形状就类似“… 相似文献
9.
相对于徒手练习,＂手指型＂划手掌辅助练习对于提高运动员200米自由泳成绩有明显作用,并有利于提高运动员的划水效率和划手频率。 相似文献
10.
11.
Previous studies of optimal swimming technique have had limited success simulating the complex motion of a swimming stroke,
either experimentally or through computer modelling. This study experimentally simulated the dynamics of the freestyle stroke
in the pull-down phase by measuring the propulsive force created by two models of human hands: one with fingers held together
and the other held with fingers spread at 10∘. The stroke motion was created by towing the model through a tank of water while
simultaneously using a two-axis motor assembly to create a sculling motion. In the testing of the models, the maximum sculling
pitch angle was varied from 20∘ to 50∘. It was determined with 95% confidence that a finger spread of 10∘ creates more stroke
force than a fingers-together configuration across all pitch angles tested. 相似文献
12.
Ice friction of flared ice hockey skate blades 总被引：2，自引：0，他引：2
In ice hockey, skating performance depends on the skill and physical conditioning of the players and on the characteristics of their equipment. CT Edge have recently designed a new skate blade that angles outward near the bottom of the blade. The objective of this study was to compare the frictional characteristics of three CT Edge blades (with blade angles of 4 degrees, 60, and 8 degrees, respectively) with the frictional characteristics of a standard skate blade. The friction coefficients of the blades were determined by measuring the deceleration of an aluminium test sled equipped with three test blades. The measurements were conducted with an initial sled speed of 1.8 m s(-1) and with a load of 53 kg on each blade. The friction coefficient of the standard blades was 0.0071 (s = 0.0005). For the CT Edge blades with blade angles of 4 degrees, 6 degrees, and 8 degrees, friction coefficients were lower by about 13%, 21%, and 22%, respectively. Furthermore, the friction coefficients decreased with increasing load. The results of this study show that widely accepted paradigms such as "thinner blades cause less friction" need to be revisited. New blade designs might also be able to reduce friction in speed skating, figure skating, bobsledding, and luge. 相似文献
13.
Abstract In ice hockey, skating performance depends on the skill and physical conditioning of the players and on the characteristics of their equipment. CT Edge have recently designed a new skate blade that angles outward near the bottom of the blade. The objective of this study was to compare the frictional characteristics of three CT Edge blades (with blade angles of 4°, 6°, and 8°, respectively) with the frictional characteristics of a standard skate blade. The friction coefficients of the blades were determined by measuring the deceleration of an aluminium test sled equipped with three test blades. The measurements were conducted with an initial sled speed of 1.8 m · s?1 and with a load of 53 kg on each blade. The friction coefficient of the standard blades was 0.0071 (s=0.0005). For the CT Edge blades with blade angles of 4°, 6°, and 8°, friction coefficients were lower by about 13%, 21%, and 22%, respectively. Furthermore, the friction coefficients decreased with increasing load. The results of this study show that widely accepted paradigms such as “thinner blades cause less friction” need to be revisited. New blade designs might also be able to reduce friction in speed skating, figure skating, bobsledding, and luge. 相似文献
14.
Handling errors are often seen in professional rugby games and even more so in amateur rugby. This paper analyses the problem
of ball mishandling using high-speed video footage of passes and a bespoke finger friction rig. The high-speed video analysis
showed that when the ball is caught, often there is a fluctuating movement of the fingers over the surface of the ball. It
also showed that the fingers move over the surface of the ball when the ball is thrown, confirming that the dynamic friction
is a good measure of how easily a ball can be handled. Rugby ball surface samples were used, on a finger friction rig, to
assess the coefficient of friction between the finger and the balls. The currently manufactured balls displaying the highest
coefficients of friction in clean, dry conditions were the design with square, ‘sharp’ pimples and also the design with a
mixture of small and large pimples. The most consistent ball across wet and dry conditions was the ball with round, large,
densely populated pimples. It was also shown that when water is added to the surface of the ball or finger, there was little
variation in performance between the ball varieties. 相似文献
15.
对手球技术中腕指动作的作用及训练进行分析、探讨。提出手指、手腕动作在手球比赛中的重要性,加强手指手腕力量的训练,从理论和实践上切实加强对传球、接球、射门技术中运用腕指技术规律及研究,为尽快提高我国手球运动的发展打下良好的基础。 相似文献
16.
皮划艇激流回旋航道产生激流的主要方法之一是在航道上不同地方安放不同大小、不同角度的丁坝,从而形成复杂的水流.因此,对丁坝绕流的研究是激流回旋运动重要的基础性研究.运用计算流体力学FLUENT软件,对4种挑角的丁坝附近水流场的水位进行了数值计算,总结速度的变化特点和一般规律,为皮划艇激流回旋运动技术提供理论上的支持,为运动员改进和完善运动技术提供科学依据. 相似文献
17.
In this study, we wished to investigate the factors that determine the direction of the spin axis of a pitched baseball. Nineteen male baseball pitchers were recruited to pitch fastballs. The pitching motion was recorded with a three-dimensional motion analysis system (1000?Hz), and the orientations of the hand segment in a global coordinate system were calculated using Euler rotation angles. Reflective markers were attached to the ball, and the direction of the spin axis was calculated on the basis of their positional changes. The spin axis directions were significantly correlated with the orientations of the hand just before ball release. The ball is released from the fingertip and rotates on a plane that is formed by the palm and fingers; the spin axis of the ball is parallel to this plane. The lift force of the pitched baseball is largest when the angular and translational velocity vectors are mutually perpendicular. Furthermore, to increase the lift forces for the fastballs, the palm must face home plate. 相似文献
18.
对我国8所高校70名女子软式排球运动员运动损伤情况进行了调查。结果显示:由于软式排球具有重量轻、球体质地柔软、动作难度较小等特点,长期大运动量、大强度运动会造成肩、肘、腕、手指及踝等关节部位的慢性损伤;随着训练年限的增长损伤率也显著增高;软式排球的技战术特点所造成身体损伤部位的比例不同;造成运动损伤的主要原因有过度疲劳、精神不集中、伤病在身、场地、器材等;高校女子软式排球运动员在训练中的损伤率远远高于比赛中的损伤率;为了减少和避免运动损伤,应加强身体素质及技战术方面的训练。 相似文献
19.
William A. Edmonds Gershon Tenenbaum Derek T. Y. Mann Michael Johnson Akihito Kamata 《Journal of sports sciences》2013,31(7):761-773
Abstract In this study, we wished to investigate the factors that determine the direction of the spin axis of a pitched baseball. Nineteen male baseball pitchers were recruited to pitch fastballs. The pitching motion was recorded with a three-dimensional motion analysis system (1000 Hz), and the orientations of the hand segment in a global coordinate system were calculated using Euler rotation angles. Reflective markers were attached to the ball, and the direction of the spin axis was calculated on the basis of their positional changes. The spin axis directions were significantly correlated with the orientations of the hand just before ball release. The ball is released from the fingertip and rotates on a plane that is formed by the palm and fingers; the spin axis of the ball is parallel to this plane. The lift force of the pitched baseball is largest when the angular and translational velocity vectors are mutually perpendicular. Furthermore, to increase the lift forces for the fastballs, the palm must face home plate. 相似文献