Simscape Fluids Valve models: Do they exhibit non-linearity too?

Hello,

Simscape Fluids VALVE models: Non-linearity

I want to model a realistic system and therefore want to view effects of and then handle the non-linearities of a valve (stiction, backlash etc.)

So do the flow-control VALVE models exhibit non-linearity too?

Rajesh

Answer 1

[Yifeng Tang]

The Simscape valve components uses the spool position signal at the S port to determine the orifice areas (or dP-Q relationships) among ports, so from the value at S to the opening area, there is no effects such as stiction or backlash. The way to model these effects in Simscape is to put that "outside" the valve and introduce non-linearity to the signal at the S port itself. A simplest way is to add a deadzone or backlash block from Simulink in the control signal and then convert it to PS. You may also model the force balance on the spool so you can use the mechanical friction block to model the stiction. A motion sensor can then be used to record the spool position and send it to the S port of the valve.