lambda2 = CubicInterpolation_lambda(Re, Re1, Re2, Delta);
Function CubicInterpolation_lambda(..)
approximates the modified friction coefficient
lambda2
=lambda*Re^2
in the transition
regime between laminar and turbulent flow of the Moody diagram by a
(direct) cubic Hermite spline interpolation. See
Modelica.Fluid.UsersGuide.ComponentDefinition.WallFriction
(especially Region 2) for a detailed
explanation.
function CubicInterpolation_lambda extends Modelica.Icons.Function; import Modelica.Math; input SI.ReynoldsNumber Re "Reynolds number (= independent variable)"; input SI.ReynoldsNumber Re1 "Boundary Reynolds number for laminar regime"; input SI.ReynoldsNumber Re2 "Boundary Reynolds number for turbulent regime"; input Real Delta "Relative roughness"; output Real lambda2 "Interpolated modified friction coefficient in transition regime"; end CubicInterpolation_lambda;