Civil - Mechanics Of Fluids - Fluid Kinematics And Dynamics
1. Define local acceleration?
It is defined as the rate of increase of velocity with
respect to time at a
given point in a flow field.
2. Define convective acceleration?
It is defined as the rate of change of velocity due to the
change of position of fluid particle in a fluid flow.
3.
Define velocity potential function?
It is defined as a scalar function of space and time such that
its negative derivative with respect to any direction gives the fluid velocity
in that direction. It is denoted by .
U,v,w are
the velocity in x,y,z direction.
4.
Mention the properties of potential function?
1.
If velocity potential exists, The flow should be
irrotational.
2.
If velocity potential satisfies the Laplace
equation, It represents the possible steady incompressible irrotational flow.
5.
Define stream function
It is defined as the scalar function of space and time, such
that its partial derivative with respect to any direction gives the velocity
component at right angles to that direction.
6.
Mention the properties of stream function?
1.
If stream function exists, it is a possible case
of fluid flow which may be rotational.
2.
If stream function satisfies Laplace equation, It
is a possible case of an irrotational flow.
7.
What is equipotential line?
A line along which the velocity potential is constant is
called equipotential line.
8.
Give the relation between stream function and
velocity potential function?
9.
What is flow net?
A grid obtained by drawing a series of equipment lines and
steam lines is called a flow net. The flow net is an important tool is analysis
two dimensional. Irrotational flow problems.
10. What are
the types of motion of fluid particle?
i.
Linear translation or pure translation
ii.
Linear Deformation
Angular Deformation
iv.
Rotation.
11. What is
linear translation?
It is defined as the movement of a fluid element in such a way
that it moves bodily from one position to represents in new position by a'b'&c'd' are
parallel.
12. What
is linear deformation?
It is defined as the deformation of a fluid element in linear
direction when the element moves the axes of the element in the deformation
position and un deformation position are parallel but their lengths changes.
13.
Define rotation of fluid element?
It is defined as the movement of a fluid element in such a way
that both of Rotate in same direction. It is equal to1/2( v/ x-u/ y) for a
two-dimensional element x, y plane.
x=1/2( w/ y- v/ z) y=1/2( u/ z- w/ x) z=1/2( u/ x- u/ y)
14.
Define vortex flow mention its types?
Vortex flow is defined as the flow of a fluid along a curved
path or the flow of a rotating mass of fluid is known as vortex flow.
i.
Forced vortex flow.
ii.
Free vortex flow.
15.
Define free vortex flow?
When no external torque is required to rotate the fluid mass
that type of flow Is called free vortex flow.
16.
Define forced vortex flow?
Forced vortex flow is defined as that type of vortex flow in
which some external Torque is required to rotate the fluid mass. The fluid mass
in the type of flow rotates at constant Angular velocity 'w'.The
tangential velocity of any fluid particle is given by v=cosr.