[basilwatson]

Hi all
I dont know How to put this , so please bear with me

Im a long time dabbler, Simple cases of flow though objects, Air through boxes , oil through pipes

Not high level at all

Im conversant with fluid flow at a basic level.

I was looking at oil flow through a pipe ( 4mm dia ) with a 3 mm dia pipe of the side and all was good.

So I tried a T junction , same settings but exits with an error message.

I couldnt determine the problem.

inexperience

So, yes I can run all the tutorials and yes I kinda understand the C++ and what each "dictionary does" but when I try and go "off piste" it all goes pear shaped and I need help.

My question eventually is; Is there a place ( here ?) where I can ask? what have I done wrong

How do I use this button

For example My inlet I tried to use Mass flow per second

but then on the outlet side I was unsure what to specify velosity or pressure, i tried both and both gave an error, Hence this post,

I hope this all makes sense.

All I would like to do is stick some oil in at one end and find out how much and how fast it comes out the other end(s)

Kind regards and hoping I could be pointed in a direction

Stephen

[AtoHM]

It might be better if you ask for help on a specific case, show your setup, what error messages you get etc.



However, there are a few places where you can read what combination of boundary conditions work well, I have quickly found this from openfoam: https://doc.cfd.direct/notes/cfd-gen...dary-condition
I remember the CFX documentation also had an overview and also somewhere on the ESI site I can remember seeing something like this.

[Yann]

Originally Posted by AtoHM

somewhere on the ESI site I can remember seeing something like this.

In the OpenCFD branch documentation there is this: https://doc.openfoam.com/2306/tools/...combinations/#

[basilwatson]

Originally Posted by AtoHM

It might be better if you ask for help on a specific case, show your setup, what error messages you get etc.
However, there are a few places where you can read what combination of boundary conditions work well, I have quickly found this from openfoam: https://doc.cfd.direct/notes/cfd-gen...dary-condition
.

Thank you
Yes I got the case running, Mesh size was the problem and just have been running the case changing one variable at a time

Some variable are obvious but others I dont quite get

Example I can input the flow in kg/s and would like to know the output in kg/s ( I know this is a simple case ) but i wasnt 100% sure of the "termanology and how it applied

It ran with static pressure but didnt with uniform velocity So I need to check my understanding of the terminology and usage

Once again thank you for your reply and link

i will don a disquise and lurk in the link

kind regards
Stephen

ps. Yes I had seen that link and the book is on order ,,, Amazing how they do it ,,, printed here in Japan and will be here thursday. In my day it took months for the scribes to finish a copy

[basilwatson]

Originally Posted by Yann

In the OpenCFD branch documentation there is this: https://doc.openfoam.com/2306/tools/...combinations/#

Thank you

Volume flow rate flowRateInletVelocity Static pressure fixedValue Excellent

This is why it worked when the outlet was "static pressure "

fixed value ! ahhh

Thank you !

Stephen