Fluid statics, continuity and Bernoulli, pipe flow and losses, momentum and flow measurement: the FE Civil Fluid Mechanics area and the base for its water resources problems.
NCEES lists these Fluid Mechanics topics for the FE Civil: flow measurement; fluid properties; fluid statics; energy, impulse and momentum. 14.6 Compressible Flow is not in the NCEES FE Civil specification, so it is not on this page.
Choose any section below to get a free FE Civil practice problem. Work it with the FE Reference Handbook open, tap your answer, then check the solution.
Pressure in a still fluid grows with depth: p = ρgh, or γh with specific weight γ = ρg.
A vertical gate 2 m wide and 3 m tall has its top edge at the water surface. What is the hydrostatic force on it?
F = γhcA = 9810(1.5)(6) = 88.3 kN.
Common trap: (B) uses the depth at the bottom edge instead of the centroid.
Fluid MechanicsHydrostatic PressureManometersBuoyancyThat was 1 of 3 problems in this section. The full course has the lesson, a worked example and every problem. Start your 3-day free trial →
Mass is conserved, so for an incompressible fluid Q = A1v1 = A2v2.
Water drains from a large open tank through an orifice 5 m below the surface. What is the ideal jet speed?
v = √(2gh) = √(98.1) = 9.9 m/s.
Continuity EquationBernoulliPitotThat was 1 of 3 problems in this section. The full course has the lesson, a worked example and every problem. Start your 3-day free trial →
The Reynolds number Re = VD/ν tells you the flow regime: laminar below about 2,300, turbulent above about 4,000.
A fitting with K = 0.5 carries water at 3 m/s. What is its minor head loss?
h = K(v2/2g) = 0.5(9/19.62) = 0.23 m.
Reynolds NumberDarcyMoodyminor lossesThat was 1 of 3 problems in this section. The full course has the lesson, a worked example and every problem. Start your 3-day free trial →
A pump adds head H; the power it needs is ρgQH/η.
A 2 m2 sign (CD = 0.5) faces a 30 m/s wind (ρ = 1.2 kg/m3). What is the drag force?
F = ½(0.5)(1.2)(900)(2) = 540 N.
Common trap: (A) drops the ½.
PumpsAffinity LawsImpulse-MomentumDragThat was 1 of 3 problems in this section. The full course has the lesson, a worked example and every problem. Start your 3-day free trial →
Venturi, orifice and nozzle meters convert a pressure drop into flow: Q = CdA√(2Δp/ρ) (for a small throat-to-pipe area ratio).
A 1:5 model in the same fluid must match the prototype’s Reynolds number. The model velocity must be:
Re = VL/ν equal with the same ν: Vm = Vp(Lp/Lm) = 5 times.
Flow MeasurementorificeSimilitudeMachThat was 1 of 3 problems in this section. The full course has the lesson, a worked example and every problem. Start your 3-day free trial →
Newton’s Notes FE Civil has 18 chapters (11 shared with Mechanical, 7 Civil-only) with lessons, worked examples and 420+ FE-style practice problems with full solutions, 171 of them Civil-only. Pro adds a timed full-length FE Civil practice exam (110 problems), a custom test builder and Ask Newton, the AI tutor. Try it free for 3 days, no card to start.
Start your 3-day free trialSee plans →