This information is part of the Modelica Standard Library maintained by the Modelica Association.
Define specialized class connector
connector flange Modelica.SIunits.Angle phi; flow Modelica.SIunits.Torque tau; end flange;
[ encapsulated ][ partial ] connector IDENT class_specifier class_specifier : string_comment composition end IDENT | "=" base_prefix name [ array_subscripts ] [ class_modification ] comment | "=" enumeration "(" ( [enum_list] | ":" ) ")" comment
See Modelica Language Specification for further details.
The keyword connector is used to define connectors, which are used in connect() statements. In connectors, no equations are allowed in the definition or in any of its components. With respect to "class", it is enhanced to allow connect(..) to components of connector classes.
Variable declarations in a connector can have the additional prefixes flow or stream, besides the prefixes input and output, that are also allowed outside of a connector. Based on the prefix, a connect() statement leads to specific connection equations, that describe the balance equations in the infinitesimal connection points.
If three connectors c1, c2, c3 with the definition
connector Demo Real p; // potential variable flow Real f; // flow variable stream Real s; // stream variable end Demo;
are connected together with
then this leads to the following equations:
// Potential variables are identical c1.p = c2.p; c1.p = c3.p; // The sum of the flow variables is zero 0 = c1.f + c2.f + c3.f; /* The sum of the product of flow variables and upstream stream variables is zero (this implicit set of equations is explicitly solved when generating code; the "<undefined>" parts are defined in such a way that inStream(..) is continuous). */ 0 = c1.f*(if c1.f > 0 then s_mix else c1.s) + c2.f*(if c2.f > 0 then s_mix else c2.s) + c3.f*(if c3.f > 0 then s_mix else c3.s); inStream(c1.s) = if c1.f > 0 then s_mix else <undefined>; inStream(c2.s) = if c2.f > 0 then s_mix else <undefined>; inStream(c3.s) = if c3.f > 0 then s_mix else <undefined>;