In car handling, slip angle is the angle between a wheel's actual direction of travel and the direction towards which it is pointing. I.e. the angle of the vector sum of wheel translational veolicty v and sideslip velocity u. This slip angle results in a force perpendicular to the wheel's direction of travel -- the cornering force. This cornering force increases approximately linearly for the first few degrees of slip angle, then increases non-linearly to a maximum before beginning to decrease. (This is directly analagous to the Coefficient of lift in Aerodynamics.) Car handling and vehicle handling is a description of the way wheeled vehicles perform transverse to their direction of motion, particularly during cornering and swerving. ... Cornering force is the sideways force produced by a vehicle tyre during cornering. ... The coefficient of lift is a number associated with a particular shape of an aerofoil, and is incorporated in the lift equation to predict the lift force generated by a wing using this particular cross section. ... Aerodynamics is a branch of fluid dynamics concerned with the study of gas flows, first analysed by George Cayley in the 1800s. ...
A non-zero slip angle arises because of deformation in the tyre carcass and tread. As the tyre rotates the friction between rubber and road means that individual tread 'elements' (infinitely small sections of tread) remain stationary with respect to the road. If a side-slip velocity u is introduced, the contact patch will be deformed. As a tread element enters the contact patch the friction between road and tyre means that the tread element remains stationary, yet the tyre continues to move laterally. This means that the tread element will be ‘deflected’ sideways. In reality it is the tyre/wheel that is being deflected away from the stationary tread element, but convention is for the co-ordinate system to be fixed around the wheel mid-plane. Contact patch is the name applied to the area of a vehicles tire that is in contact with the road surface. ...
As the tread element moves through the contact patch it will be deflected further from the wheel mid-plane:
Image File history File links TreadDeflected1. ...
This deflection gives rise to the slip angle, and to the cornering force.
Slide angle is the angular difference between the direction inertia sends you and the direction your tires are pointing while slipangle is the angular difference between the direction your contact patch is pointed (thus, the direction the tire moves) and the direction the tire is pointed.
That is, a slipangle is so called because the part of the contact patch that is to the outside of your turn is moving faster than the wheel itself is in the direction it (the contact patch) is pointing while the part on the inside is moving more slowly.
The greater the slipangle, the larger portion of the contact patch that is slipping.
In car handling, slipangle is the angle between a rolling wheel's actual direction of travel and the direction towards which it is pointing (i.e., the angle of the vector sum of wheel translational velocity v and sideslip velocity u).
A non-zero slipangle arises because of deformation in the tire carcass and tread.
A principal means of adjusting developed slipangles is to alter the relative roll couple (the rate at which weight transfers from the inside to the outside wheel in a turn) front to rear by varying the relative amount of front and rear lateral load transfer.
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