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.
Shear velocity, also called friction velocity, is a form by which a shear stress may be re-written in units of velocity.It is useful as a method in fluid mechanics to compare true velocities, such as the velocity of a flow in a stream, to a velocity that relates shear between layers of flow.
As for friction, it is a result of both microscopic adhesion and chemical bond formation due to the electromagnetic force, and of microscopic structures stressing into each other; [3] in the latter phenomena, in order to allow motion, the microscopic structures must either slide one above the other, or must acquire enough energy to break one ...
Note the minus sign in the equation, the drag force points in the opposite direction to the relative velocity: drag opposes the motion. Stokes' law makes the following assumptions for the behavior of a particle in a fluid: Laminar flow; No inertial effects (zero Reynolds number) Spherical particles; Homogeneous (uniform in composition) material
The static friction increases or decreases in response to the applied force up to an upper limit determined by the characteristics of the contact between the surface and the object. [ 3 ] A static equilibrium between two forces is the most usual way of measuring forces, using simple devices such as weighing scales and spring balances .
Friction is the least-used of the six methods of producing energy. If a cloth rubs against an object, the object will display an effect called friction electricity. The object becomes charged due to the rubbing process, and now possesses an static electrical charge, hence it is also called static electricity. There are two main types of ...
Sliding friction (also called kinetic friction) is a contact force that resists the sliding motion of two objects or an object and a surface. Sliding friction is almost always less than that of static friction; this is why it is easier to move an object once it starts moving rather than to get the object to begin moving from a rest position.
Tribology is the science and engineering of understanding friction, lubrication and wear phenomena for interacting surfaces in relative motion.It is highly interdisciplinary, drawing on many academic fields, including physics, chemistry, materials science, mathematics, biology and engineering. [1]