Fluid Mechanics (Mech)
Bernoulli, viscosity, pumps, turbines, pipe flow.
Fluid Mechanics (Mech) — Overview
Bernoulli, viscosity, pumps, turbines, pipe flow.
Fluid Mechanics — Bernoulli, pumps, turbines
Notes
Fluid properties:
- Density (ρ = m/V).
- Viscosity (η): resistance to flow.
- Surface tension.
- Compressibility.
Pressure:
- P = ρgh (hydrostatic).
- Pascal's law: pressure transmitted equally in all directions.
- Atmospheric pressure ≈ 101.325 kPa.
Buoyancy (Archimedes):
- F_buoyant = ρ_fluid · V_submerged · g.
- Floating: ρ_body < ρ_fluid.
Bernoulli's Equation:
P + ½ρv² + ρgh = constant (energy conservation per unit volume).
Continuity Equation:
A₁v₁ = A₂v₂ (incompressible).
Applications:
- Venturi meter, Pitot tube (flow measurement).
- Pumps: centrifugal, reciprocating. Specific speed.
- Turbines: Pelton (impulse), Francis (reaction), Kaplan (axial).
- Pipe flow: Darcy-Weisbach friction loss.
Reynolds number:
Re = ρvD/η. Re < 2000: laminar; Re > 4000: turbulent.
Common formulas:
- Discharge Q = AV.
- Power of pump = ρgQh.
- Velocity head = v²/(2g).
RRB JE focus: Bernoulli numerical, pump/turbine selection, basic pressure calculation.