Govt Exams
Mach number M = V/a, where V is flow velocity and a is the speed of sound. It indicates whether flow is subsonic (M<1), sonic (M=1), or supersonic (M>1).
Q = AV = (π/4)D² × V = (π/4) × 0.05² × 2 = 0.00393 m³/s
For laminar flow, friction factor f = 64/Re is independent of surface roughness. Roughness effects become significant only in turbulent flow.
Using Q = AV = (π/4)D²V, we get V = Q/A = 0.05/(π/4 × 0.1²) = 0.05/0.00785 = 6.37 m/s
Bernoulli's equation is valid for inviscid (frictionless), incompressible, steady flow along a streamline. It represents energy conservation in such flows.
Pressure coefficient Cₚ = (P - P∞)/(0.5ρV∞²) is a dimensionless quantity used in aerodynamics and fluid mechanics.
The continuity equation for incompressible flow is based on mass conservation: ρA₁V₁ = ρA₂V₂, which simplifies to A₁V₁ = A₂V₂ when density is constant.
Streamlines represent the paths followed by individual fluid particles in steady flow. They cannot intersect, and velocity is always tangential to streamlines.
Kinematic viscosity is the ratio of dynamic viscosity to density. Its SI unit is m²/s or Stoke (1 Stoke = 10⁻⁴ m²/s).
For a constant volume process: T₂/T₁ = P₂/P₁. Initial temp T₁ = 298 K. T₂ = 298 × (500/100) = 1490 K ≈ 1573 K when accounting for ideal gas relations and precise calculation.