This is a partial model of the pressure loss in a pipe. The pressure loss is implemented using a characteristic curve as shown in figure 1. The curve loss represents the relation between the pressure loss and the medium mass flow rate. This curve has two areas: the laminar area between the lam points and the turbulent area outside the lam points. The laminar area is defined by two laminar operating points. Between these two lam points the relation between the laminar mass flow rate and the laminar pressure is implemented with a linear function. The turbulent area is implemented with a quadratic function. This quadratic function has the same slope as the laminar area curve in the lam points.

Figure 1: Relation between the medium pressure and the medium mass flow rate in a component.