Search results
Results from the WOW.Com Content Network
The capstan equation [1] or belt friction equation, also known as Euler–Eytelwein formula [2] (after Leonhard Euler and Johann Albert Eytelwein), [3] relates the hold-force to the load-force if a flexible line is wound around a cylinder (a bollard, a winch or a capstan).
The following formula describes the viscous stress tensor for the special case of Stokes flow. It is needed in the calculation of the force acting on the particle. In Cartesian coordinates the vector-gradient is identical to the Jacobian matrix. The matrix I represents the identity-matrix.
Coulomb friction, named after Charles-Augustin de Coulomb, is an approximate model used to calculate the force of dry friction. It is governed by the model: , where is the force of friction exerted by each surface on the other. It is parallel to the surface, in a direction opposite to the net applied force.
If the value of the friction factor is 0.016, then the Fanning friction factor is plotted in the Moody diagram. Note that the nonzero digits in 0.016 are the numerator in the formula for the laminar Fanning friction factor: f = 16 / Re . The procedure above is similar for any available Reynolds number that is an integer power of ten.
In fluid dynamics, the Darcy friction factor formulae are equations that allow the calculation of the Darcy friction factor, a dimensionless quantity used in the Darcy–Weisbach equation, for the description of friction losses in pipe flow as well as open-channel flow.
If the coefficient of friction is defined as: [4] = where is the tangential force. Then K can be defined for abrasive wear as work done to create abrasive wear particles by cutting to external work done: [4]
The friction drag force, which is a tangential force on the aircraft surface, depends substantially on boundary layer configuration and viscosity. The net friction drag, D f {\displaystyle D_{f}} , is calculated as the downstream projection of the viscous forces evaluated over the body's surface.
where is the force (positive in compression), is the total surface energy of both surfaces per unit area, and is the equilibrium separation of the two atomic planes. The Bradley model applied the Lennard-Jones potential to find the force of adhesion between two rigid spheres.