FE Chemical Fluid Mechanics and Dynamics Practice Problems

The current FE Chemical specification assigns 8-12 of the 110 exam questions to Fluid Mechanics and Dynamics. Form A contains 9 original problems in this area. The sample below is published in full, with the same worked-solution format used throughout the book.

Free sample problem

A liquid of density 850 kg/m3 and viscosity 0.012 Pa s flows at 1.8 m/s in a 40 mm pipe. Reynolds number is most nearly:

(A)204
(B)2550
(C)5100
(D)10200

Show worked solution

Answer: (C)

Re=rho V D/mu=5,100.

Pipe Reynolds number compares inertial and viscous effects.

R e = \frac{ρ V D}{μ}

The diameter is 0.040 m.

R e = 850 (1.8) (0.040) /0.012 = 5100

FE Reference Handbook — Fluid Mechanics: Reynolds Number

Why the other choices appear

(A)Using pipe radius and an extra viscosity factor understates Reynolds number.
(B)Using radius instead of diameter halves Reynolds number.
(D)Using twice the pipe diameter doubles Reynolds number.

The complete FE Chemical practice exam contains 9 problems in this area and 110 problems overall, with an answer key, full solutions, and a score sheet by knowledge area.

Free FE Chemical problems in the other knowledge areas

Mathematics · Probability and Statistics · Engineering Sciences · Materials Science · Chemistry and Biology · Thermodynamics · Material and Energy Balances · Heat Transfer · Mass Transfer and Separation · Solids Handling · Chemical Reaction Engineering · Economics · Process Design · Process Control · Safety, Health, and Environment · Ethics and Professional Practice

Retaking this exam? The FE exam retake guide turns the NCEES diagnostic report into an area-by-area plan.