Learning Forum

[Jamessmp23]

Hello,

I'm repeating result from the paper using S-N drag with out any UDF, but got the result quite similar with the UDF drag.

Does it possible that the newer version of Fluent was improved the calculation method ? then I got the result like this.

Or I misunderstand, the results has to be the same as S-N from the reference paper. If I misunderstanding anything please inform. 

another question is for the interstitial liquid velocity,

Can anyone suggest me to measure the interstitial liquid velocity ? for this simulation I measure it like this [picture 3] to get results as the graph above [picture 1]. 

and I had tried to plot the water magnitude velocity in the riser and I got the result like this [picture 4] and I tried to get the average velocity but not get the same result as the paper.

Thank you,

Sumit

 

[Amine Ben Hadj Ali]

1/ multiphase runs have been enhanced from stability perspective but the drag has not changed. You might become a dmore deeper converged run. In the first picture there is a difference between SN and the exp. data.

2/I guess they are measuring the hold ups and the velocities along some dedicated points and not along position. You need to check the paper for that.

[Jamessmp23]

Thanks for the reply,

I'm not sure that I understand it correct or not. Do you mean the fluent calculation method was upgraded then I got the deeper converged results which more similar to the experiment results ? 

for the gas holdup results was agreed with the paper simulation but for the liquid interstitial velocity at the downcomer was acceptable but at the riser was not.
it should be similar result for the interstitial liquid velocity at the riser if using the same measurement as the gas holdup.

in the paper, they measured the experimental data using the probe at the top and bottom of the riser as picture 3 but they did not say anything on the fluent measurement.

regards,

Sumit

.

 

[Amine Ben Hadj Ali]

1/Most probably: enhancement of schemes and methods which we do continuously.

2/I will guess that the same method is used to get the velocity: you need to create a point and to monitor the velocity there. You can contact the paper's author to double-check.

 

[Jamessmp23]

Thanks for the advice,

Sumit