Contents
What is rigid body motion of a fluid?
Rigid body rotation occurs when a fluid is rotated without relative motion of fluid particles. This is the case, for example, of a fluid placed in a cylindrical container on top of a turntable rotating with a constant angular velocity, .
What is responsible for rotating rigid body?
When a rigid object rotates, every part of it (every atom) moves in a circle, covering the same angle in the same amount of time, a. Every atom has a different velocity vector, b. Since all the velocities are different, we can’t measure the speed of rotation of the top by giving a single velocity.
What is the equation of motion of a rotating rigid body?
Analogous to Newton’s law (F = Δ( mv)/Δ t) there is a rotational counterpart for rotational motion: t = Δ L/Δ t, or torque is the rate of change of angular momentum.
What is the equation of rotational motion?
These equations can be used to solve rotational or linear kinematics problem in which a and α are constant. ω ¯ = ω 0 + ω 2 and v ¯ = v 0 + v 2 . ω ¯ = ω 0 + ω 2 and v ¯ = v 0 + v 2 ….Tips For Success.
| Rotational | Linear | Relationship |
|---|---|---|
| θ | x | θ = x r θ = x r |
| ω | v | ω = v r ω = v r |
| α | a | α = a r α = a r |
When does a fluid have rigid body motion?
In past articles I have talked about the pressures a fluid can experience when it is completely at rest. However, there are cases where a fluid could be in motion but behave like a rigid body. In other words it would have rigid body motion. A fluid that is experiencing rigid body motion will not experience any shear stress.
Which is the correct equation for rigid body rotation?
For rigid body rotation there are parabolic surfaces where constant pressure will occur. As a result d p will equal 0. Taking this into account equation 6 can be modified to take inconsideration of a surface of constant pressure.
What kind of motion can a fluid have without shear stress?
There are two types of motion that a fluid can experience without experiencing shear stress. These two types of motion are straight linear motion and rigid body motion around a fixed axis. First, lets return to the example above where there is a glass of water inside a car that is accelerating in a straight line.
What happens when water moves as a rigid mass?
Once the water inside that glass starts to move as a rigid mass there will be no shear stress within the fluid. As a result you will be able to use equations 1 and 2 to calculate the pressure variations of the water inside the glass.