|
[Sponsors] |
Boundary condition for alternating material inflow |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
May 24, 2018, 11:50 |
Boundary condition for alternating material inflow
|
#1 |
New Member
MAR
Join Date: May 2018
Location: Germany
Posts: 1
Rep Power: 0 |
Hello,
I want to have an inflow of two materials through the same inlet however, alternately rather than simultaneously. The model being used is Multiphase - Volume of Fluid. The velocity of the mixture will be fixed while the volume fraction for each material would be continously and alternatingly switched from 1 to 0 and vice versa, so as to simulate slug flow with slugs of defined lengths. These lengths would obviously depend on the switching times, which in turn would be a function of the mixture velocity and the time step size. From what I have read, it seems that I need to write a User Defined Function to change the boundary condition continuously during the calculation. My first question is whether or not this approach would be correct. Additionally, I understand that I could use two inlets instead of a single inlet but, a changing boundary condition would certainly save me a lot of time. If UDF is the way to go, I believe that I would need to call the volume fraction, the mixture velocity, and the time step size in my UDF. I do not understand how to reference these variables in C. Would anyone be kind enough to point me in the right direction? I would like to thank you in advance. Best regards, MAR |
|
May 24, 2018, 13:56 |
|
#2 |
Member
zobekenobe
Join Date: Mar 2009
Location: Dublin, Ireland
Posts: 72
Rep Power: 17 |
Hi Mar,
You can use the FLUENT udf manual You mainly have to use the defined the macros to interact with the conditions for your domain. the DEFINE_PROFILE macro should allow you to define the boundary conditions on whichever boundary you specify to apply it. CURRENT_TIME is the fluent special macro that would allow you use the flow time to give a periodic boundary condition for different inlet conditions. there are multiphase macros which you can then explore to access each phase and their volume fraction I hope this helps you get started cheers!! |
|
Tags |
boundary condition, fluent - udf, vof multiphase |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Radiation in semi-transparent media with surface-to-surface model? | mpeppels | CFX | 11 | August 22, 2019 08:30 |
My radial inflow turbine | Abo Anas | CFX | 27 | May 11, 2018 02:44 |
Problem in setting Boundary Condition | Madhatter92 | CFX | 12 | January 12, 2016 05:39 |
Question about heat transfer coefficient setting for CFX | Anna Tian | CFX | 1 | June 16, 2013 07:28 |
An error has occurred in cfx5solve: | volo87 | CFX | 5 | June 14, 2013 18:44 |