This is a partial model of the prescibed pressure loss in a valve. The pressure loss is implemented with prescibed linear characteristic curves as shown in figure 1 and with prescibed quadratic characteristic curves as shown in figure 2. It is possible to define the type of the characteristic curve (linear or quadratic) with the parameter characteristic

The curve position=1 represents the relation between the pressure loss and the medium mass flow rate with linear characteristic at opened valve and the curve position=0 represents the relation between the pressure loss and the medium mass flow rate with linear characteristic at closed valve. The operating point nom is defined at nominal mass flow rate and nominal pressure and the operating point leak is defined at leak mass flow rate and nominal pressure as illustrated in figure 1. The linear characteristic curve changes as the valve position changes.

Figure 1: Relation between the medium pressure in a component and the medium mass flow rate with prescribed linear pressure loss characteristic.

The curve position=1 represents the relation between the pressure loss and the medium mass flow rate with quadratic characteristic at opened valve and the curve position=0 represents the relation between the pressure loss and the medium mass flow rate with quadratic characteristic at closed valve. The operating point nom is defined at nominal mass flow rate and nominal pressure and the operating point leak is defined at leak mass flow rate and nominal pressure as shown in figure 2. The quadratic characteristic curve changes as the valve position changes.

Figure 2: Relation between the medium pressure in a component and the medium mass flow rate with prescribed quadratic pressure loss characteristic.