Fluid Mechanics

Continuity Equation

A statement that mass flow rate is conserved along a streamtube.

For an incompressible fluid in steady flow, the product of cross-sectional area and average velocity is constant along the tube. Narrowing the pipe therefore speeds the fluid up in exact proportion.

Continuity is almost always the first equation to write in a flow problem, because it supplies the velocity that Bernoulli or the energy equation then needs.

How much of the FE Civil exam is Fluid Mechanics?