Mass Flow Rate on the Interior Surface
 

Hi,

I would like to get the mass flow rate of inflow and outflow on a interior surface. How can I get this data?

Thanks a lot.

Re: Mass Flow Rate on the Interior Surface
 

go to report - fluxes in the main fluent command menus.

Re: Mass Flow Rate on the Interior Surface
 

Hi,

Thanks for your response.

The report-flux is a net-flux. How do I individually get the mass flow rate of inflow or outflow on the same interior surface?

Re: Mass Flow Rate on the Interior Surface
 

For 2-D, create a line where you want the mass flow rate from "Surface>Line/Rake" then go to "Report>Surface integrals> select the created line and mass flow rate..

Rajesh

Re: Mass Flow Rate on the Interior Surface
 

sorry I don't know but if it were me I would look up the index in the documentation.

Re: Mass Flow Rate on the Interior Surface
 

Hi Phil,

If you keep on telling people to look at the documentation you can almost hardly avoid any posts to be replied like that. As a regular reader of this forum for more than 3 years, I understand that some are asking very basic questions which they can get answers for documentation. But if you have a clear answer in your hand, what's the harm in giving those to them? and being a teacher, I know the diffculties of some students who do read documentation but hardly understand some key points due to many problems, one of which is the language. But the same people can easily make it out if some body explains them in a simple manner. I too benefitted from many questions & answers which seemed simple to people like you. This forum is mainly meant for discussion and sharing your ideas. So please don't discourage people to ask and share their ideas with others as this forum, I feel, is more useful to such people who ask basic doubts

:)

Rajesh

Re: Mass Flow Rate on the Interior Surface
 

Rajesh I find you offensive. If you look at my posts I normally answer questions in a very detailed manner or tell people who are trying to avoid bothering doing any work to stop being lazy and read the user guide. I am the top poster being above Mr Second Place by >4x, yet I have only asked 1 or 2 questions myself.

IN THIS SPECIFIC CASE I WAS SIMPLY SUGGESTING USING THE USER GUIDE, AS THIS IS WHAT I WOULD DO MYSELF WHEN I'M SOLVING MY PROBLEMS.

If I don't know the answer to a question I don't post and in this example I only found out later that Barii already knew what I wrote.

WHY DON'T YOU GO AND ANSWER AFEW PEOPLES POSTS THEN COME BACK AND TELL ME WHAT THE POST. I NOTICE YOU HAVE BEEN A READER FOR 3 YEARS AND NOT A RESPONDER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!

Re: Mass Flow Rate on the Interior Surface
 

First thing-Sorry If you feel I was offensive. What made me write that is, I found too many posts of you which contain the same message.

Second thing-This is not a class room my friend, where you are bound to answer for all questions, and its not mandatory that you should answer all the questions, and I don't try giving "free" advices like what you do.

Third thing- Strange!!, you want to be the top poster by posting "free" advices like "read the manuals?"

Re: Mass Flow Rate on the Interior Surface
 

So your reason for posting any reply is to be the top poster. Grow up!

Re: Mass Flow Rate on the Interior Surface
 

Who do you think you are?

I have spent hours on here trying to help people because I enjoy to do so and let me assure you there are other things I could be doing that would benefit me more.

Only very few of my posts have this answer.

I HAD AT LEAST 5 EMAILS YESTERDAY ALONE SAYING THANKS FOR THE ADVICE IT WORKED!! CHECK MY RECENT POSTS.

I never said I wanted to be top poster, just because you are not intelligent enough to understand what I say doesn't give you the right to abuse me. I simply noticed that I happened to be top poster.

I never said this was a classroom. I ONLY TELL PEOPLE TO CHECK THE DOCUMENTATION WHEN I REMEMBER SEEING THE ANSWER THERE BUT NOT WHAT IT ACTUALLY WAS.

WHY ARE YOU ALL HAVING A GO AT ME? I HAVE HELPED LOTS OF PEOPLE ON HERE AND DON'T DESERVE IT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I ONLY HAVE 6 MONTHS CFD EXPERIENCE AND I'M ON HERE TRYING TO LEARN AS WELL!!! IM ONLY A FUCKING STUDENT YOU ARROGANT POMPOUS FUCKS.

Re: Mass Flow Rate on the Interior Surface
 

WHY IS IT THAT YOU HAVE CHOSEN TO INSULT ME WHEN EVERYONE ELSE WHO POSTS ME SAYS THANKS FOR THE HELP. I ONLY USUALLY SAY CHECK THE DOC WHEN I REMEMBER SEEING THE ANSWER THERE.

YOU SHOULD BE ASHAMED OF YOURSELF ABUSING SOMEONE WHO SPENDS ALOT OF TIME HELPING PEOPLE.

IF YOU CHECK MY POSTS I ONLY OCCASIONALLY SAY CHECK THE DOC. AGAIN YOU SHOULD BE ASHAMED OF YOURSELF, UNGRATEFUL GREEDY PEOPLE LIKE YOU ARE WHAT IS WRONG WITH THE WORLD!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Re: Mass Flow Rate on the Interior Surface
 

Don't you call this an insult.

"IM ONLY A FUCKING STUDENT YOU ARROGANT POMPOUS FUCKS"

Even if you were insulted I do not think you should use this kind of language.

Come on, behave yourself and grow up.

Re: Mass Flow Rate on the Interior Surface
 

oh i apologize for being childish!, at least I post helpful comments rather than only saying grow up.

if you're only on here to wind people up then don't you think your life is quite sad?

Re: Mass Flow Rate on the Interior Surface
 

My dear Phil..

I do understand that you are really taking a lot of pains to answer for others post. Believe me! I am regular reader of all of your posts. I am happy that you are giving good hints to others. Please remember that I just commented about your comments to "go through the documentation". What I wanted to say in my first post is, people might've gone though the documentation but could hardly understand the points what they want, ofcourse, there are people who don't spend even 1 minute to read through the documents as well. Instead of telling them "go through the documents" why can't you tell them the answer,if you have one. If you don't have one in your hand, why bother abt those posts?

Then about the abusing... This is your misunderstanding about the posts. Here nobody is trying to abuse you or insult you. This forum is not meant for that but only sharing the thoughts as we friends do. I think you are taking things seriously due to your immature nature(don't get angry on that word!!). Then, the sentence which Josh pointed out ("YOU ARE A ....). Please remember that you are posting in an international forum which people from many parts of the world go through. In some places, these words are considered very bad and not even used in the worst human moods. If you are using such words which seem common in your place, in a reputed forum like this, you can just have a thought about what people will think about you and your place!

regards Rajesh

Re: Mass Flow Rate on the Interior Surface
 

Barii,

Could you solve the problem?

Re: Mass Flow Rate on the Interior Surface
 

No, Josh was trying to wind me up in my opinion. I tell people to check the doc mainly when I know it's there but can't remember exactly what the answer is.

I am sick of your 'constructive criticism', mainly because Josh chose to butt in and try to belittle me. Perhaps I should point out more where in the doc to look but that wasn't what you took it upon yourself to tell me.

If I am "immature" it may be because I'm only 24. I have learned to a high level CFD in 6 months by constantly referring to the tutorials and documentation, and only learned of this site when I had a problem with my model. PERHAPS SOME BEGINNERS ON THIS SITE SOMETIMES JUST NEED REMINDING THAT ALMOST EVERYTHING THEY ASK ON THIS SITE CAN BE FOUND QUICKLY IN THE USER GUIDES?

Finally, the only reason I started posting on this site was that I found I could quickly help people and this is exactly what 75% of my posts do, not to try and be the top poster. I assure you that in my recreational time I have a more exciting life than Josh and hence have no time to come on here to piss people off for kicks.

PS. I AM HAVING A BIG PROBLEM WITH MY MODEL JUST NOW AND HAVE POSTED A QUESTION. CAN EITHER OF YOU HELP?(DOUBT IT!!!) I THOUGHT THIS WAS A FORUM FOR PEOPLE TO GAIN HELP IN SOLVING CFD PROBLEMS RATHER THAN GAINING COACHING IN BEING A MORE MATURE INDIVIDUAL.

Re: Mass Flow Rate on the Interior Surface
 

If the face is lined up with one coordinate (x,y,z) you can get the positive and negative velocities for the face and calcualte the mass flow. If it's not aligned, then you can always use the transform matrix to calculate the velocity normal to the face using field functions.

Re: Mass Flow Rate on the Interior Surface
 

"I THOUGHT THIS WAS A FORUM FOR PEOPLE TO GAIN HELP IN SOLVING CFD PROBLEMS RATHER THAN GAINING COACHING IN BEING A MORE MATURE INDIVIDUAL."

You told this because you are not reading through all forums Phil. If you go to the main forum (..all other forums as well) and see what is being posted, you can see how people are not only being helped in their CFD problems, but in lots of other problems (..like how to behave and comment in a forum too)

"I AM HAVING A BIG PROBLEM WITH MY MODEL JUST NOW AND HAVE POSTED A QUESTION. CAN EITHER OF YOU HELP?(DOUBT IT!!!)"

I am not an expert in Fluent. I use another software and my own code. So I cannot help you. (but I don't like to post "Sorry I don't know, you better check the documents" simply because I don't know the answer) If you have doubt(!!) over that, why did you ask that to us?

Re: Mass Flow Rate on the Interior Surface
 

I used Iso-clip on this surface to create two surface. One is a positive velocity, another is a negative velocity. I used Report->Surface Integrals->Mass Flow Rate to get each flux for the two surface and net flux. However, the net flux value is different from that used Report->Fluxes...->Mass Flow Rate. Why is the difference between the two method?

Re: Mass Flow Rate on the Interior Surface
 

Barii,

The Report>Flux>Mass flow rate calculates the net mass flow rate across ALL inflows and outflows, say If you have 2 inltes and 3 outlets, this will show the individual mass flow rates for all 5 in/out flows, as well as the net mass flow rate through all these faces. You can create ISO-SURAFCES in all inflows and outflows and check the mass flow rates using these ISO-SURFACES with that of Report>Flux>mass flow rate. This is just for checking whether you are doing the iso-surafce mass flow rate calculation correctly. Then you can create another ISO-SURFACE at the location where you want to check the mass flow rate.

Rajesh

Re: Mass Flow Rate on the Interior Surface
 

I think when you split the face using iso-clip, the node values are used and as a results subsequent calculations may be not as accurate as you want. Chances are that even when you add up the areas of the neg. and pos. they won't give you the exact total area either. Maybe a finer mesh (adapt) can help reduce the difference.

I assume you are doing the split on a pre-defined face that you are also able to check the report --> flux, right?

Re: Mass Flow Rate on the Interior Surface
 

AGAIN: When have I ever posted this comment? There may be afew times I have thought someone is just being lazy and decided to write this! I have made this point clear in most of my messages to you! On this actual thread I didn't start my messages with this, you should maybe look at my first post on this thread!!??

After asking advice from several friends on how to get you to just leave me alone - they told me to tell you where to go!, but I have decided to simply say that I will not respond again, and the above text is simply me repeating what I have already said!

Regarding my comments you keep bringing up, I was being sarcastic. You should look up the meaning on the web to better explain this. And in my opinion your behavior is worse than mines, as you have behaved in an arrogant manner, and if you look up the English language meaning of this also on the web or a dictionary you will see that I am correct.

So, to summarize, ok then yes I am immature, but you are arrogant, self righteous, intrusive and rude, as if you have no experience of fluent then you should not comment in the fluent forum and certainly not to someone who has helped(check my recent posts) so many people but maybe didn't indicate where in the documentation the answer was!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Re: Mass Flow Rate on the Interior Surface
 

No comments!

Rajesh

Re: Mass Flow Rate on the Interior Surface
 

I also don't like to comment on this

Rajesh

Re: Mass Flow Rate on the Interior Surface
 

Hi Barii,

You should have access to the Fluent OTS site. Under "Solution 522: Calculate massflow rate and maximum temperature at an interior face " the Fluent guys give a UDF to calculate the mass flow.

If this is a post-processing surface, then Bashu's comments above apply. One other workaround is to go back to your mesh and generate an interior boundary in gambit at the location where you need to monitor. This should help to get more accurate data out.

Thanks for your posting. The last time I has so much fun getting up to speed on the phil.osophy side of CFD was when John C. Chien was still a regular poster.