• Streamline − Path taken by a fluid particle under a steady flow

The tangent to streamline at any point gives the direction of the flow of liquid at that point.

• Two streamlines do not cross each other.

• Flow rate remains constant throughout the pipe of flow.

Av = Constant

Where,

A − Area of cross-section

v − Velocity of flow

At two points of streamline,

A₁v₁ = A₂v₂ [This is called equation of continuity]

• Steady flow is possible only at low speed.

• Turbulent flow − unsteady motion of the elements of the liquid along a zig-zag path

• Critical velocity − limiting value of velocity beyond which the liquid stops flowing as streamline and becomes turbulent

Bernoulli’s Principle

• The sum of pressure energy, kinetic energy, and potential energy per unit mass is always constant for the streamline flow of a non-viscous and incompressible fluid.

Consider,

A₁ − Area of cross-section at B

P₁ − Pressure at A₁

h₁ − Height of B

h₂ − Height of D

A₂ − Area of cross-section at E

P₂− Pressure at A₂

v₁ − Speed at B

v₂ − Speed at D

BC = v₁Δt

DE = v₂Δt

Δt − Time interval<...