CFD Online Discussion Forums - periodic, unsteady, non-constant mass flow rate

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)

- FLUENT (https://www.cfd-online.com/Forums/fluent/)

- - periodic, unsteady, non-constant mass flow rate (https://www.cfd-online.com/Forums/fluent/29454-periodic-unsteady-non-constant-mass-flow-rate.html)

Quote:

Originally Posted by Lee
;99996

Hello.

In a periodic, unsteay, 3-D flow simulation, I'd like to set a non-constant mass flow rate condition varying with time, for example;

Mass flow rate at periodic boundaries = function of time = m * Sin(a*t)

Would you please send me the method?

Thank you.

Lee

Dear Mohammad,

Finally, it's better to take look to the first post of this thread I mentioned above, as you can see, periodic unsteady flow is desired as a general flow, something like flow over boxes with unsteady flow rate; after these discussions, I'm really eager to know whether your suggestion is proper for this case or not? I don't think so. :D:cool::)

Bests,

hi amir,
taking a look at post #7 (2011 not post #1 in 2002!!), I think ac problem is a simple duct(2d) and wants to solve a fully developed flow with pressure gradient changing by a function. so it is not a general periodic flow which I had mentioned that needs a periodic BC I post #13. so I think I am careful enough!!

Quote:

Originally Posted by m2montazari (Post 326813)

Dear Mohammad,

I just wanted to show you restrictions of your suggestion; but that's not a reason for which I wanted you to be more careful, you completed your suggestion in a relatively long discussion and I'll be wonder if you were aware of all its aspects from the beginning.
Additionally, you have to notice all of the posts before answering regardless of dates! or at least explain restrictions from beginning. Anyway, this thread is always open for you if you can find a good suggestion for general case which cover all the posts without JOURNAL. :D

Bests,