Search results
Results From The WOW.Com Content Network
Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. [7] [8] Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces. [9] [10] [11] Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body.
The microscopic origin of contact forces is diverse. Normal force is directly a result of Pauli exclusion principle and not a true force per se: Everyday objects do not actually touch each other; rather, contact forces are the result of the interactions of the electrons at or near the surfaces of the objects. [1]
This theory is exact for the situation of an infinite friction coefficient in which case the slip area vanishes, and is approximative for non-vanishing creepages. It does assume Coulomb's friction law, which more or less requires (scrupulously) clean surfaces. This theory is for massive bodies such as the railway wheel-rail contact.
The reason why the form of the friction curve for liquid lubricated surfaces was later attributed to Stribeck – although both Thurston and Martens achieved their results considerably earlier – may be because Stribeck published his findings in the most important technical journal in Germany at that time, Zeitschrift des Vereins Deutscher ...
Traction can also refer to the maximum tractive force between a body and a surface, as limited by available friction; when this is the case, traction is often expressed as the ratio of the maximum tractive force to the normal force and is termed the coefficient of traction (similar to coefficient of friction).
Figure 2: Weight (W), the frictional force (F r), and the normal force (F n) acting on a block.Weight is the product of mass (m) and the acceleration of gravity (g).In the case of an object resting upon a flat table (unlike on an incline as in Figures 1 and 2), the normal force on the object is equal but in opposite direction to the gravitational force applied on the object (or the weight of ...
Ball bearings are an example of an attempt to minimize the friction torque. [2] Friction torque can also be an asset in engineering. Bolts and nuts, or screws are often designed to be fastened with a given amount of torque, where the friction is adequate during use or operation for the bolt, nut, or screw to remain safely fastened.
Belt friction is a term describing the friction forces between a belt and a surface, such as a belt wrapped around a bollard.When a force applies a tension to one end of a belt or rope wrapped around a curved surface, the frictional force between the two surfaces increases with the amount of wrap about the curved surface, and only part of that force (or resultant belt tension) is transmitted ...