This information is part of the Modelica Standard Library maintained by the Modelica Association.

Calculation of a generic pressure loss in dependence of a pressure loss coefficient.

Calculation

The mass flow rate m_flow is determined by:

m_flow = rho*A_cross*(dp/(zeta_TOT *(rho/2))^0.5

with

A_cross	as cross sectional area [m2],
dp	as pressure loss [Pa],
rho	as density of fluid [kg/m3],
m_flow	as mass flow rate [kg/s],
zeta_TOT	as pressure loss coefficient [-].

Verification

Compressible case [Mass flow rate = f(dp)]:

The mass flow rate M_FLOW in dependence of the pressure loss dp for a constant pressure loss coefficient zeta_TOT is shown in the figure below.

Note that the verification for dp_pressureLossCoefficient is also valid for this inverse calculation due to using the same functions.

References

Elmqvist, H., M.Otter and S.E. Cellier:

Inline integration: A new mixed symbolic / numeric approach for solving differential-algebraic equation systems.. In Proceedings of European Simulation MultiConference, Prague, 1995.

Wischhusen, S.:

Dynamische Simulation zur wirtschaftlichen Bewertung von komplexen Energiesystemen.. PhD thesis, Technische Universität Hamburg-Harburg, 2005.