Page tree

Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

LaTeX Math Inline
body--uriencoded--f(%7B\rm Re%7D, \, \epsilon)

Darcy friction factor

LaTeX Math Inline
body--uriencoded--\displaystyle %7B\rm Re%7D = \frac%7Bu(l) \cdot d%7D%7B\nu%7Dnu(l)%7D

Reynolds number

LaTeX Math Inline
body--uriencoded--\displaystyle d = \sqrt%7B \frac%7B4 A%7D%7B\pi%7D%7D

characteristic linear dimension of the pipe

(or exactly a pipe diameter in case of a circular pipe)

...

Pressure profilePressure gradient profileFluid velocityFluid rate


LaTeX Math Block
anchorH8MPT
alignmentleft
p(l) = p_0 + \rho \, g \, z(l) - \frac{\rho_0 \, q_0^2 }{2 A^2 d} \, f_0 \, l



LaTeX Math Block
anchorIFPGP
alignmentleft
\frac{dp}{dl} = \rho \, g \cos \theta(l) - \frac{\rho_0 \, q_0^2 }{2 A^2 d} \, f_0 



LaTeX Math Block
anchor1
alignmentleft
u(l) = u_0 = \frac{q_0}{A} = \rm const



LaTeX Math Block
anchor1
alignmentleft
q(l) =q_0 = \rm const


...

LaTeX Math Inline
body\displaystyle \cos \theta(l) = \frac{dz(l)}{dl}

correction factor for trajectory inclination


Expand
titleDerivation


Panel
borderColorwheat
bgColormintcream
borderWidth7

Incompressible fluid 

LaTeX Math Inline
body\rho(p) = \rho_0 = \rm const
 means that fluid velocity is going to be constant along the  trajectory 
LaTeX Math Inline
body--uriencoded--u(l) = u_0 = \frac%7Bq_0%7D%7BA%7D = \rm const
.

The Reynolds number 

LaTeX Math Inline
body--uriencoded--\displaystyle %7B\rm Re%7D = \frac%7Bu_0 \cdot d%7D%7B\nu_0%7D
 may still be varying along the trajectory due to the influence of temperature profile on kinematic viscosity 
LaTeX Math Inline
body--uriencoded--\nu(l) = \frac%7B\mu(T(l))%7D%7B\rho_0%7D




The first term in 

LaTeX Math Block Reference
anchorIFPGP
defines the hydrostatic column of static fluid while the last term defines the friction losses under fluid movement:

...