otised,

Thanks for your attention, but I couldn't download the file, the link has a problem, please check it and address me again.

<b>moderator's note: Link is fine, you need to copy and paste it into a browser and remove the spaces the forum software inserts.</b>

 

How does the flow not decrease if dP decreases? Isn't dP the only driving force for flow through an orifice? Do you mean an upstream disturbance?

Please clarify how choked flow can cause large downstream pressure excursions?

Thanks

 

Slightly off topic.

A good example of a valve operating under choke flow conditions would be an engine fuel injector.

The P1 pressure is held to about 45 psig by a backpressure regulator but the P2 can be anywhere between atmosphere and a near vacuum.

Since the injector is always under choke flow conditions the flow rate while the injector is open is constant, to vary the flow rate the engine controller just holds the injector open for more or less time.