Hi,

You may consider this link to support your work :

http://www.engsoft.c...team_flow_e.htm

In case ,you will find some print out from Chemical engineering journal.

Hope this is helping you

Breizh

Hi Breizh,

and thanks a lot for your contribution.

I've read the article at your hyperlink.

But I don't think that those calculations mentioned can sufficiently describe my application.

Since they take an approach at thermodynamic equilibrium ? and the discussed equations are mostly for ideal gases and steam applications.

In my case one of the main problems is calculating the specific volume of my mixture once it's pressure is beneath saturation condition.

When I calculate this volume in accordance with classical equilibrium thermodynamics the changes in density / specific volume are with an factor of around 1000.

Which means, if I use the continuity equation in accordance with equilibrium approach, the velocity will suddenly skyrocket. I've already calculated a maximum velocity which should occur at isentropic nozzle flow via h_0 = h + v^2/2 (like in PRV sizing for 2 phase flow.pdf). But the velocity with equilibrium calculations and occuring phase change is bigger than this max velocity.

But considering boiling delay, the mixture should stay in a liquid phase for much longer. Maybe even not flash at all during the flow through the nozzle.

My knowledge of HNE-CSE is limited to **Sizing of rupture disks for two-phase gas/liquid flow according to HNE-CSE-model** by Jürgen Schmidt and Sara Claramunt , this document

https://indico.cern....enf_Handout.pdf

and a few other papers,

the segmental solution you mentioned may recall the direct integration method (HEM) but I have not the german version of the "VDI-Heat-Atlas" to verify,

may I suggest to contact the author, Dr. JÜRGEN SCHMIDT ?

Hey Paolo,

yes, I've read those paper and the hand out as well. I don't think it has anything to do with the HEM, since it's clearly an application of the HNE-CSE Model. Unfortunately the segmental approach seems only to be found in the "VDI-Heat-Atlas"

Stagnation conditions are mentioned in most articles related to this topic. But mostly the entrance speed to the orifice is assumed to be negligable and thus stagnation conditions won't differ from the actual conditions. And I've found no way to calculate them.

I've already contacted Prof Schmidt and his suggestion to do the isentropic flash and obtain the stagnation condition was to use the first law, the continuity eq. and if neccessary the perfect gas relation p*v**kappa = const. but I wasn't able to solve it with this information.

The thing is that I really need to know whats happening in the nozzle and at its exit, since it should be used as an motive nozzle for an jet ejector.