Fluid mechanics could be defined as the division of engineering science which deals with the behaviour of the fluid in both motion and rest situations.
Fluid mechanics is one of the four divisions of mechanics namely quantum mechanics, relative mechanism, fluid mechanics and elastic body mechanics.
Fluid mechanics is separated into three distinct classes. These are statics, kinematics, and the dynamics out of which static and dynamics are then divided into a compressible and incompressible flow. These are furthermore split into turbulent and laminar forms.
Fluid mechanics is grounded upon five principles of physics and they are as follows:
- Conservation of linear momentum
- Conservation of angular momentum
- Conservation of energy
- Conservation of mass
- Conservation of thermodynamics
In fluid mechanics, if the speed of flow of a liquid if not too huge then it generally flows in coats with regular gradation in their respective velocities and therefore called streamline flow. While if the rate of flow is too high then numerous irregularities begin to show and do not flow in layers which we term as turbulent flow. The turbulence commences after the critical velocity which is given by a relation
Vc = Critical velocity
k = Reynolds number
η = coefficient of viscosity of the fluid
σ = density of the fluid
r = radius of the tube
If the velocity of the fluid reaches a value such that the Reynolds number gets a value greater than(>)4000 then the flow is turbulent.