Learning Forum

[sinan ozbolgili]

Hi,

Please see below picture . There is a tank and filled with water. Inside tankt three is a heated to to boil water inside tank . 
Water inside tank is 373.15 K and boiling will be sart at 373.15 K as well. 
Tube Wall temperature is 379.15 K (Super ehat is 6K) 

Initially: Water(primary) volume fraction is  1  - Vapur(secondary)  volume fraction is 0 

Moel : Euler - RPI boiling 

Could you pelase specfy how to set outlet pressure settings? Backflow temperature of water and backflow temperature of vapur ? 








Also, another question what can be rason of vapor volume fraction is getting reduce after waiting a bit ? 

[SRP]

Hi,

For outlet pressure setting, you can check user's guide: 48.7. Boundary Conditions Task Page (ansys.com)

Plot is showing zero flow time and zero vof. Can you please recheck graph?

Thank you.

[sinan ozbolgili]

Hi,

after waiitng a bit I  am getting floating error. 

[SRP]

Hi,

A floating point exception is an error that occurs with a floating point number, such as divide by zero.

In fluent floating point error can be caused by many factors such as, improper mesh size, defining some property close to zero. However, floating point exception is very specific case that is being solved, the actual reason can be determined by changing one quantity (can be mesh, model, parameters, boundary conditions etc.) at the time.

 

Can you please try to check mesh?

 

Thank you.

[sinan ozbolgili]

Hi, I know that things you explanaied but I want to just say I am tring to use Eulerian -RPI model .

I am getting result when I select fisrt order voluma fraction but when I change to HRIC the error dispaying. 

[SRP]

Hi,

With HRIC as the interface scheme gives medium accuracy and high speed during simulation with both implicit and explicit.

Thank you.

[sinan ozbolgili]

another qustion, 

 

standrd state entalpy,  I will put below value but should I put for water or vapout ? I think for vapout below value and for water it should be 0, right ? 

It is boiling   

 j/kgmol constant 43987714

[SRP]

Hi,

yes correct

[sinan ozbolgili]

and lats question,

 

pelase see picture i shared in first message. there a hole which is represent to tube.
Do I need use mesh interface here or no need? 

 

[SRP]

Hi,

For the part which is overlapping, it creates interfaces. For the part of the boundary zone which is not overlapping, fluent creates additional wall boundary zones. if boundary zones are perfectly overlapping, these new wall boundary zones could be empty. 

Thank you.