CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > CFX

[Transient rotating domain initialization from steady state run

Register Blogs Community New Posts Updated Threads Search

 
 
LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
Old   June 13, 2019, 17:28
Post [Transient rotating domain initialization from steady state run
  #1
New Member
 
Andrea Sanchez
Join Date: Nov 2018
Location: Montreal, CA
Posts: 1
Rep Power: 0
asanchez84 is on a distinguished road
Hello,

I'm want to run a transient simulation of an axial pump (stator-rotor - stator) using a converged steady-state result file as the initialization for my transient simulation.

***I started a simple model in which I would like to rotate the second section of the cylinder for a better understanding of the complexity of the problem***

While the initial conditions for the stationary domains are successfully interpolated, I'm receiving the following error:

_______________________________________

| FATAL ERROR :
|
| Initial values are required for all variables in TRANSIENT runs.
| In this simulation, no initial value was set for
|
| Variable: Velocity
| Domain: Impeller
|
| The value can be set using the Initialisation Branch in CFX Pre.
|
| To bypass this message and use default solver initial values,
| set the expert parameter "transient initialisation override = t"

___________________________________

I know that the Domain Initialization tab of the Impeller Domain should be defined in order to proceed with the simulation.

Therefore, I decided to use a Rotating Frame Type to apply the initialization values relative to the Impeller domain and the Automatic Cartesian Velocity components to evaluate the last iteration of my steady run, but this option didn't work.

I would like to use the cartesian velocity components (u,v,w) of the last iteration of the steady state run to start the transient run.

Is there any way I could storage these values on the steady run and use them as a CEL function on my transient run? or which would be the best way to do it? (I'm connecting the CFX blocks instead if loading the solution file for the Initial Values)

I've played around with a Domain Initialization using 0 [m s^-1]for each velocity component (u v w) and static pressure of 0 Pa and the solution correctly integrates the steady and transient run (Image below). But I know this affects the transient run and I would like to take the steady continuous to start the transient one.

I've attached several attachments for a better understanding of my problem

Many thanks!

Andrea
Attached Images
File Type: jpg solution steady run and transient.jpg (117.6 KB, 16 views)
File Type: png steady and transient.png (14.2 KB, 17 views)
File Type: jpg final velocity steady run.jpg (85.5 KB, 23 views)
File Type: jpg solution steady run.jpg (109.8 KB, 13 views)
File Type: jpg initial timestep transient simulation.jpg (96.2 KB, 18 views)
asanchez84 is offline   Reply With Quote

 

Tags
domain initialization, rotary parts, stationary fluid, transient 3d


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Domain Reference Pressure and mass flow inlet boundary AdidaKK CFX 75 August 20, 2018 05:37
Periodic Pressure drop cfd_begin CFX 10 May 25, 2017 07:09
Wrong flow in ratating domain problem Sanyo CFX 17 August 15, 2015 06:20
Has anyone EVER managed to run: compressible steady state subsonic internal flow mihaipruna OpenFOAM Running, Solving & CFD 2 November 9, 2012 11:23
initialization of flow field to enhance convergence rate to steady state vfico Main CFD Forum 0 September 9, 2009 11:23


All times are GMT -4. The time now is 04:59.