查询词典 friction coefficient

The mean velocity distributions in turbulent boundary layers of smooth surface and two different riblet surfaces are measured with IFA300 constant-temperature anemometer in low-speed wind tunnel to validate the full development of turbulent boundary laye. Friction velocity and wall friction stress of turbulent boundary layer are obtained with the least-squares fitted curve of the sublayer velocity distribution based on Spalding formula, and virtual origin position of riblet surface can be acquired accurately.

在低速风洞中来流速度一定的情况下使用IFA300恒温热线风速仪测量了光滑表面和两种不同尺寸的脊状表面湍流边界层平均速度分布剖面，并验证了试验段湍流发展的充分性；通过应用Spalding壁面公式使用最小二乘法精准拟合了实验测量的边界层内层速度分布曲线，得到了湍流边界层壁面摩擦速度并进一步求得湍流壁面摩擦应力，较准确地计算出脊状表面的虚拟原点位置，并通过与对数律公式拟合结果比较分析，证实了该方法更加准确有效。

It involves a simple mechanical principle: sliding friction, rolling friction small.

它涉及一个简单的机械原理：滑动摩擦大、滚动摩擦小。

It involves a simple mechanical principle: a large sliding friction, rolling friction small.

它涉及一个简单的机械原理：滑动摩擦大、滚动摩擦小。

Friction.1. Friction causes a rolling ball to stop finally.

摩擦力使得一只滚动的球最终停了下来。

In fact, M0 accounts for the additional external sources of friction, together with the "hydrodynamic" component of rolling friction, which also has a load dependent part.

实际上，M0代表额外的外部摩擦来源，再加上滚动摩擦中的"流体动力"成份，而这一成份中也有一部分与负荷相关。

It has high friction properties, resemble anti-wear properties and brake moment curve compared with Dunlop company and Messier-Bugatti company carbon brake discs materials. It has excellent mechanics performance and axis heat conduct coefficients compared with abroad carbon brake discs materials. The friction properties of RTO Wetness normal brake increased by 23％-29% than Dunlop carbon brake discs materials.

与英国Dunlop公司、法国Messier-Bugatti公司生产的炭刹车盘材料相比，其高摩擦特性及抗磨损性能相当，刹车力矩曲线形态相似，且力学性能、轴向导热系数明显高于国外炭刹车盘材料，RTO刹车湿态刹车时的摩擦特性高出Dunlop炭刹车盘材料23％-29%。

The cohesion and the internal friction angle are functions of water content index; cohesion-degree of saturation curve and internal friction angle-degree of saturation curve are gotten by simulating shear experiment through different paths, through which shear strength parameters can be obtained; CDSC and IFADSC are approximating straight lines in the same path when the change of saturation degree is small.

非饱和土抗剪强度的黏聚力和内摩擦角是含水指标的函数；通过模拟不同路径下非饱和土抗剪试验，得到黏聚力-饱和度曲线和内摩擦角-饱和度曲线，进而得到非饱和土抗剪强度指标；在同一路径小区间范围内CDSC和IFADSC曲线近似为直线。

Then, the friction torque to affect the ultra-low-speed tracking performance is analyzed, and a mathematical model of the servomotor with large friction torque is established.

对影响其超低速跟踪性能的摩擦力矩进行了分析，建立了大摩擦力矩条件下的中空马达数学模型。

Lastly ,The study result of tests of negative skin friction are introduced, the influence of the construction technology on negative friction is proposed.

本文最后介绍了桩基负摩阻力的试验研究成果，分析了不同的成桩工艺对桩基负摩阻力的影响。

The test running results under the condition of dry sliding friction show that the experimental friction system is feasible.

干摩擦条件下的系统试运行结果初步验证了试验系统的可行性。

He tendered his resignation to the Prime Minister.

他向首相递了辞呈。不适合

International economy and trade,Nanking 210044

国际经济与贸易，南京 210044