...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Medicine and science in sports and exercise >Measuring changes in aerodynamic/rolling resistances by cycle-mounted power meters.
【24h】

Measuring changes in aerodynamic/rolling resistances by cycle-mounted power meters.

机译：通过循环式功率计测量空气动力学/滚动阻力的变化。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

PURPOSE: : To develop a protocol for isolating changes in aerodynamic and rolling resistances from field-based measures of power and velocity during level bicycling. METHODS: : We assessed the effect of body position (hands on brake hoods vs drops) and tire pressure changes (414 vs 828 kPa) on aerodynamic and rolling resistances by measuring the power (Pext)-versus-speed (V) relationship using commercially available bicycle-mounted power meters. Measurements were obtained using standard road bicycles in calm wind (<1.0 m.s) conditions at constant velocities (acceleration <0.5 m.s) on a flat 200-m section of a smooth asphalt road. For each experimental condition, experienced road cyclists rode in 50-W increments from 100 to 300 W for women (n = 2) or 100 to 400 W for men (n = 6). Aerodynamic resistance per velocity squared (k) was calculated as the slope of a linear plot of tractive resistance (RT = power/velocity) versus velocity squared. Rolling resistance (Rr) was calculated as the intercept of this relationship. RESULTS: : Aerodynamic resistance per velocity squared (k) was significantly greater (P < 0.05) while riding on the brake hoods compared with the drops (mean +/- SD: 0.175 +/- 0.025 vs 0.155 +/- 0.03 N.V). Rolling resistance was significantly greater at 60 psi compared with 120 psi (5.575 +/- 0.695 vs 4.215 +/- 0.815 N). CONCLUSIONS: : These results demonstrate that commercially available power meters are sensitive enough to independently detect the changes in aerodynamic and rolling resistances associated with modest changes in body position and substantial changes in tire pressure.
机译：目的：：开发一种协议，以从水平骑行过程中基于动力和速度的现场测量中隔离空气动力学和滚动阻力的变化。方法：通过商业上测量功率（Pext）与速度（V）的关系，我们评估了身体位置（手在刹车罩上相对于下落）和轮胎压力变化（414对828 kPa）对空气动力学和滚动阻力的影响。可用的自行车功率计。使用标准公路自行车在平稳的沥青路面平直的200 m区域上以恒定的速度（加速度<0.5 m.s）在平稳风（<1.0 m.s）条件下进行测量。对于每种实验条件，经验丰富的公路骑行者以50 W的增量骑行，女性从100到300 W（n = 2），男性从100到400 W（n = 6）。每速度平方的空气动力阻力（k）计算为牵引阻力（RT =功率/速度）与速度平方的线性图的斜率。计算滚动阻力（Rr）作为该关系的截距。结果：与下降相比，在制动罩上骑行时，每速度平方的气动阻力（k）明显更大（P <0.05）（平均+/- SD：0.175 +/- 0.025 vs. 0.155 +/- 0.03 N.V）。 60 psi时的滚动阻力明显高于120 psi（5.575 +/- 0.695 N对4.215 +/- 0.815 N）。结论：这些结果表明，商用功率计足够灵敏，可以独立检测与适度的车身位置变化和轮胎压力的显着变化相关的空气动力学和滚动阻力的变化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号