Learning Forum

[mvidal]

Hi all,

the design task is to modify the tubes between the two cylinders to achieve similar massflow in both.

to show the problem I created a simple model and added the massflow calculations.

The massflwo at inlet and outlet match.

I split the model to get faces between the fluid volumes.

You can derive a massflow from theses internal faces. The picture shows results for both contacting faces and for each of them. These numbers do not match at all what you get at the outlet.

How can you derive the massflow in a section of a fluid model?

 

regards

Marc 

[Gaurav Sharma]

@Hi @Marc Vidal

I have heard that splitting fluid volume to create internal faces the way you have done is not supported and is probably the culprit in this case.

Nevertheless in order to further debug, Is it possible for you to share this model. I hope it is not confidential.

Regards,

Gaurav

[mvidal]

Hi Gaurav,

 

I send you a testing model.

 

regards

Marc

🛈 This post originally contained file attachments which have been removed in compliance with the updated Ansys Learning Forum Terms & Conditions

[Gaurav Sharma]

Marc Vidal 

Thanks for sharing the file. I looked into it and can confirm that the problem is solely because calculators do not support measuring on faces internal to the volume. That face does not exist when it gets to the physics since flow passes through it.

I understand that this restricts you from designing the tubes by measuring mass flow through them individually. However, I would like to propose following workaround that might help you in this case.

Step-1. From the simulation you have already performed, extract Pressure at any point of tube 1 & 2 respectively, as shown at mid length of the tubes in image below

 

Step-2. With the reduced model (extracted by cutting through the tubes), impose the pressure outlet conditions at tube ends, use the pressure extracted in step 1(see image).

 

This way the physics in the reduced model is a mimic of actual model and the mass flow at the outlets can easily be monitored using calculation. I hope you will find this approach useful. Please let me know if you want me to elaborate or if any further assistance is required.

Best Regards,

Gaurav

[mvidal]

Gaurav_ANSYS 

although not the final solution:

Good idea!

Thanks!

 

Marc

[Gaurav Sharma]

Marc Vidal 

I understand that this is only an approximate approach and would thus encourage you to post you suggestion of having calculators function on internal faces as well in the ideas section