model HollowCylinderRadialFlux "Hollow cylinder with radial flux; constant permeability"
extends FluxTubes.Interfaces.PartialForce;
SI.Length l = s "Axial length (orthogonal to direction of flux)"
annotation (Dialog(
group = "Variable geometry",
groupImage = "modelica://Modelica/Resources/Images/Magnetic/FluxTubes/Shapes/HollowCylinderRadialFlux.png"));
parameter SI.Radius r_i = 0.01 "Inner radius of hollow cylinder";
parameter SI.Radius r_o = 0.015 "Outer radius of hollow cylinder";
SI.MagneticFluxDensity B_avg "Average flux density (at arithmetic mean radius)";
protected
SI.Area A_avg "Average cross-sectional area orthogonal to direction of flux (at arithmetic mean radius)";
equation
A_avg = pi * (r_i + r_o) * l;
B_avg = Phi / A_avg;
G_m = mu_0 * mu_r * 2 * pi * l / Modelica.Math.log(r_o / r_i);
dGmBydx = mu_0 * mu_r * 2 * pi / Modelica.Math.log(r_o / r_i) * dlBydx;
annotation (
defaultComponentName = "force",
Documentation(info = "<html>\n<p>\nPlease refer to the enclosing sub-package <a href=\"modelica://Modelica.Magnetic.FluxTubes.Shapes.Force\">Force</a> for a description of all elements of this package and to <a href=\"modelica://Modelica.Magnetic.FluxTubes.UsersGuide.Literature\">[Ro41]</a> for derivation and/or coefficients of the equation for permeance G_m.\n</p>\n</html>"));
end HollowCylinderRadialFlux;