\rho \left(  \frac{\partial u}{\partial t} + u \frac{\partial u}{\partial l} \right)=
-\frac{\partial p}{\partial l}  + \rho \, g \, \cos \theta + f_{\rm cnt, \, l}

where

	time
	distance along the fluid flow streamline
	inclinational deviation,
	elevation along the 1D flow trajectory
	fluid pressure
	fluid density
	fluid velocity vector
	fluid velocity module
	standard gravity constant
	volumetric density of all contact forces exerted on fluid body
	projection of onto the unit fluid velocity vector:

See also