Question

If the velocity, pressure and density do not change at a point with respect to time, the flow is called:
1. Uniform flow
2. Eulerian flow
3. Lagrangian flow
4. Steady flow

Answer 1

Correct Answer - Option 4 : Steady flow

Concept

There are many different types of flow and are classified as below:

1. Steady flow: it is defined as a type of flow in which the fluid characteristics like velocity (V), pressure (P), density (ρ), etc. at a point do not change with time.

Steady flow is mathematically represented as

​\(\left (\frac{\partial V}{\partial t} \right )_{x_{o},{y_{o}},{z_{o}}} = 0\),\(\left (\frac{\partial P}{\partial t} \right )_{x_{o},{y_{o}},{z_{o}}} = 0\), \(\left (\frac{\partial ρ}{\partial t} \right )_{x_{o},{y_{o}},{z_{o}}} = 0\)

2. Unsteady flow: is defined as a type of flow in which velocity pressure or density at a point changes with respect to time.
3. Uniform flow: is defined as a type of flow in which velocity at any given time does not change with respect to space (i.e., length of direction of the flow)
   • uniform flow is mathematically represented as \(\left (\frac{\partial V}{\partial s} \right )_{t\ =\ constant} = 0\)
   • \(\partial V\) = Change of velocity, \(\partial s\) = Length of flow in the direction s
4. Non - uniform flow: is a type of flow in which velocity at any given time changes with respect to space.