What is tractive force of a channel?
What is tractive force of a channel?
The permissible tractive force is the maximum shear stress that will not cause erosion of the material forming the channel bed on a level surface. The value, obtained from laboratory experiments, is called the critical tractive force.
What is meant by tractive force method?
Essentially an analytical stable design method, the tractive force approach utilizes a critical shear stress to define when initiation of motion begins, the point at which the channel becomes unstable. In HEC-RAS, this concept is followed to allow the user to solve for two dependant variables when two others are given.
How do you calculate tractive force?
2. The tractive efficiency of the wheel (TE) can be calculated as the ratio between tractive power and the wheel axle power, as shown in Equation 3.1. 3. The friction force (Ff in Figure 3.1….Mechanics of Traction.
| Surface type | Equivalent coefficient of friction (μ)[a] |
|---|---|
| Concrete | 0.91–0.98 |
What is tractive force in water?
The basic mechanism that controls the sediment transport, is the drag force exerted by water in the direction of flow on the channel bed. This drag force is also known as tractive force or shear force. This force is nothing but a pull of water on the wetted area of the channel.
What is traction force in physics?
Traction, or tractive force, is the force used to generate motion between a body and a tangential surface, through the use of dry friction, though the use of shear force of the surface is also commonly used.
What is tractive effort & What are the forces that resist?
The tractive effort required to overcome train resistance: The resistance of the train is mainly due to various kinds of friction. The three basic types of friction responsible for the train resistances are Coulomb friction, viscous friction and air friction.
What is meant by tractive resistance?
The resistance to motion due to friction per unit weight hauled.
What is unit tractive force?
In hydraulics, drag or shear developed on the wetted area of a streambed, acting in the direction of flow. As measured per unit of wetted area, unit tractive force equals the specific weight of water times hydraulic radius times slope of channel bed (Chow, 1957).
What is the tractive effort and tractive resistance?
When tractive effort TE is equal to the tractive resistance TR a vehicle would be either stationary or moving at a uniform velocity. It the tractive effort exceeds the resistance the vehicle will accelerate until the tractive effort once again equals the tractive resistance.
What is forward tractive force?
As used in mechanical engineering, the term tractive force can either refer to the total traction a vehicle exerts on a surface, or the amount of the total traction that is parallel to the direction of motion.
What is the distribution of unit tractive force in a canal?
The distribution of unit tractive force or shear stress is rectangular for bottom and parabolic for banks as shown in Fig. 18.7. The value of unit tractive force (shear stress) also depends on the curvature of the canal. Permissible tractive force for curved and straight canals are given as follows:
What is a trapezoidal channel section?
A trapezoidal channel section is usually used for erodible channels.To design these channels, first an appropriate value for the side slope is elected so that the sides are stable under all conditions. 13. Basic Definitions Froude’s Number (FN) It is the ratio of inertial forces to gravitational forces.
How do you find the disturbing force of a canal?
The stability of horizontal bed of the canal and developed equation τ = ωSD or ωSR where τ is the tractive or disturbing force. But on the slope of the banks there is one more disturbing force i.e. the component of the weight of the particle.
What is the average unit tractive force given by ωsr?
Weight of water acting in vertical direction = ωAL. Horizontal component of this weight = ωAL sin θ. But θ is slope of the channel which is represented by S. ∴ Horizontal component of weight = ωALS. Hence average unit tractive force also known as shear stress is given by τ = ωSR.