Fluids Pipe Flow

Question 1

Continuity equation workflow

Answer 1

A1V1 = A2V2. EXAM TRAP: Use volumetric flow, not mass flow unless density varies.

Question 2

Bernoulli equation with losses

Answer 2

z1+P1/γ+V1²/2g = z2+P2/γ+V2²/2g + hL. EXAM TRAP: Losses always added.

Question 3

Darcy-Weisbach application

Answer 3

hf = f(L/D)(V²/2g). EXAM TRAP: hf is head, not pressure.

Question 4

Moody chart usage

Answer 4

Determine friction factor from Re and ε/D. EXAM TRAP: Use relative roughness.

Question 5

Laminar vs turbulent flow cutoff

Answer 5

Laminar if Re < 2300. EXAM TRAP: Friction factor independent of roughness in laminar.