Fluid Mechanics (Part-2) (General Engineering) (SSC JE)

When the material comprising the bed is coarse and non-cohesive it is mainly the submerged weight of the sediment particle that resists motion the coarse particles move as single entities. However, when the material is fine and contains silts and clays cohesive forces are predominant and they resist motion in such a mateial lumps of particle move as a unit.

Surface tension–It is that property of a liquid which enables it to resist tensile stress it is expressed in N/m.

Drag force–The force on an object by a fluid to resist its motion through it is called the drag force. If the fulid is air then it is called aerodynamic drag force.

In viscous flow fluid particles move along straight parallel paths in layers it occurs at low velocity and viscous force, predominates inertial force.

The Bernoulli's equation states that for a perfect incompressible liquid flowing in a continuous stream. The total energy of particle remains the same, while the particle moves from one point to another. Bernoulli's equation is given as–

Bernoulli’s equation–The Bernoulli's equation state that for a perfect incompressible liquid, flowing in a continuous stream, the total energy of a particle remains the same, while the particle moves from one point to another.

Continuity equation–If an incompressible liquid is continuously flowing through a pipe or a channel, the quantity of liquid passing per second is the same at all sections. This is known as equation of continuity of a liquid flow.