= Control volume
{title2=$V$}
A <control volume> is a chosen region over which fluid <mass conservation> and momentum balance are integrated. It may be fixed or move with a prescribed <velocity>. Boundary fluxes must use <velocity> relative to the moving boundary. In <Stokes flow>, negligible inertia reduces the momentum balance to the sum of body <forces> and boundary tractions, making a carefully chosen <control volume> useful for finding drag without integrating directly over a curved body.
Back to article page
