[neetu kumari]

Hello everyone

To simulate the cavitating flow, FLUENT has used A K Singhal's full cavitation model. But the model equations for rate of evaporation or condensation has inconsistency in dimensions. The correct unit of rate of evaporation or condensation should be kg/m3.s, but according to the above mentioned model equations the unit of that particular rate is coming as kg/m4 (by assuming that the empirical constants are dimensionless). If empirical constants have unit then what its value in particular SI unit and if not then how this could be possible?

If I have some misconceptions then please help me out.

Thank you.

[shk12345]

Can you share the paper which has the caviation model in it so that i can have a look at the dimension

regards
shk

[neetu kumari]

Originally Posted by shk12345

Can you share the paper which has the caviation model in it so that i can have a look at the dimension

regards
shk

Here is the full reference of that paper.

SINGHAL A.K., ATHAVALE M.M., HUIYING L., JIANG, L., 2002. Mathematical bases and validation of the full cavitation model. J Fluids Eng 124, 617-624.


Thanks

[shk12345]

Originally Posted by neetu kumari

Here is the full reference of that paper.

SINGHAL A.K., ATHAVALE M.M., HUIYING L., JIANG, L., 2002. Mathematical bases and validation of the full cavitation model. J Fluids Eng 124, 617-624.


Thanks

Hi
i tried to asses the journal but it is blocked at my place . I f you have acces to that paper can you send me that paper .

Regards
shk

[Tingyun YIN]

Originally Posted by neetu kumari

Hello everyone

To simulate the cavitating flow, FLUENT has used A K Singhal's full cavitation model. But the model equations for rate of evaporation or condensation has inconsistency in dimensions. The correct unit of rate of evaporation or condensation should be kg/m3.s, but according to the above mentioned model equations the unit of that particular rate is coming as kg/m4 (by assuming that the empirical constants are dimensionless). If empirical constants have unit then what its value in particular SI unit and if not then how this could be possible?

If I have some misconceptions then please help me out.

Thank you.

Hi, buddy. Now I have the same problem about the unit. How do you solve it? Any comments are appreciated.

[jcw]

Hello!
(1) I also read A. K. Singhal paper and I came across the same question about the SI-units of Rc and Re. If Cc and Ce are dimensionless, Rc and Re have SI-unit of [kg/m⁴]. I am expecting SI-unit of [kg/(m³s)]. It is also written in the paper, that Rc and Re are 'phase change rates'. So, there should be Time (s) included in SI-unit of Rc and Re.
(2) fg: Is there a model how to implement a transport equation for non-condensable gas (fg)? In my opinion, fg varies in fluid domain and depends on absolute pressure.

I am posting this to ANSYS/Fluent Forum, as I am continuing this thread. But this is a comprehension question, independent of solver. I am glad to read your comments.


Thanks for feedback.

[jcw]

Originally Posted by jcw

Hello!
(1) I also read A. K. Singhal paper and I came across the same question about the SI-units of Rc and Re. If Cc and Ce are dimensionless, Rc and Re have SI-unit of [kg/m⁴]. I am expecting SI-unit of [kg/(m³s)]. It is also written in the paper, that Rc and Re are 'phase change rates'. So, there should be Time (s) included in SI-unit of Rc and Re.
(2) fg: Is there a model how to implement a transport equation for non-condensable gas (fg)? In my opinion, fg varies in fluid domain and depends on absolute pressure.

I am posting this to ANSYS/Fluent Forum, as I am continuing this thread. But this is a comprehension question, independent of solver. I am glad to read your comments.


Thanks for feedback.

Hello!

Finally, I found one paper (Modelling and Validation of Cavitating Orifice Flow in Hydraulic Systems, P. Casoli) which is dealing with the transport equations for non-condensable gas. I am struggeling with the definition of the mentioned equilibrium differential pressure, as used in eqn. 5. Can someone help?

Thanks and regards.