**Steady Flow:**

Velocity, pressure and other properties like cross-section of fluid flow are the functions of time. If these fluid properties do not change w.r.t time, it is called steady flow.

Mathematically, steady flow equations can be written as-

Let V be the velocity of fluid particles

a be the acceleration of fluid particles

We know that,

V ⃗ = V (S ⃗)

a ⃗ = a (S ⃗)

So, steady flow equation w.r.t. time changes can be given by-

[∂V/∂t](x0, y0, z0) = 0

[∂P/∂t](x0, y0, z0) = 0

[∂ρ/∂t](x0, y0, z0) = 0

Where,

P = Pressure of fluid flow

ρ = Density of fluid

x0 = Initial component of x

y0 = Initial component of y

z0= Initial component of z

**Unsteady Flow:**

If Velocity, pressure and other fluid properties change w.r.t time, it is called unsteady flow.

Mathematically, unsteady flow equations can be written as-

[∂V/∂t](x0, y0, z0) ≠ 0

[∂P/∂t](x0, y0, z0) ≠ 0

[∂ρ/∂t](x0, y0, z0) ≠ 0

**Links of Previous Main Topic:-**

- Vapour compression refrigeration cycle introduction
- Basic fluid mechanics and properties of fluids introduction
- Fluid statics introduction
- Manometers measurement pressure
- Fluid kinematics
- Lagrangian method for describing fluid method
- Eulerian method for describing fluid method
- Lagrangian relationship from eulerian equations
- Steady and unsteady flows

**Links of Next Mechanical Engineering Topics:-**

- Uniform and non uniform flows
- Stream line
- Path lines
- Streak lines
- Acceleration of a fluid particle
- Continuity equation
- Continuity equation in three dimensions in differential form
- Continuity equation in a cylindrical polar coordinate system
- Bernoullis equation
- Basics and statics of particles introduction
- Equilibrium of rigid bodies introduction