CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > Siemens > STAR-CCM+

Non-iterative method in CCM+

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   June 13, 2020, 04:01
Default Non-iterative method in CCM+
New Member
Join Date: Dec 2017
Posts: 7
Rep Power: 4
Kukka is on a distinguished road
Dear all,

I am a new user of CCM+ and I have used Fluent for quite sometime.

My work is related to swirling flows for which I am using LES closure with WALE Subgrid Scale model. My CCM+ settings include a constant density flow, Implicit unsteady with time step size of 0.1ms (this resulted in convective Courant number of less than 5) and 2nd-order temporal discretization, High-Accuracy Temporal Discretization Option with Optimized 2nd-order (5), MinMod limiter method, MUSCL 3rd-order/CD Convection in Segregated flow, Maximum Inner Iterations were 5 (default) and this has resulted in residuals to fall below 0.001 except axial velocity, that did not go below 0.01. No Synthetic Turbulence Specification in the initial conditions were considered. For Relaxation Scheme,Gauss-Seidel approach has been used. Regarding the mesh, I have tried both uniform trimmer mesh (without prism layers over the walls) as well as block structured mesh generated in ICEM CFD.

With these settings, I am unable to extract the correct RMSE values (calculated from Variance of the flow variables). In the regions where the velocity fluctuations are very large (experimentally), the solver elucidates significantly damped fluctuation levels; at some locations, instead of a shoot up, I can see a dip! Did I do something wrong with the solver settings? Inlet is velocity inlet, outlet is pressure outlet (zero gauge pressure), and rest all walls with no-slip condition.

Secondly, in Fluent (using LES), I have used non-iterative scheme with fractional time step, and this has reduced the wall-clock time per time step calculation. Unfortunately, I could not find any such setting in CCM+. I have also searched in the user guide as well as Siemens support portal but could not find any. Are there non-iterative options for incompressible turbulent flows in CCM+ similar to fractional time step option?

Any reference on this would also help me a lot.
Kukka is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Vortex Panel Method Rafaelle55 Main CFD Forum 1 December 17, 2018 10:16
Finite element method ANSYS CFX tomd97 CFX 2 April 4, 2018 04:10
Convergence of Gauss Seidel Iterative Method mechie94 Main CFD Forum 5 September 20, 2017 11:35
" SLOR " iterative method Klashincovisky Main CFD Forum 0 February 1, 2013 12:27
Info on method of lines approach charlie ryan Main CFD Forum 2 August 9, 2007 11:06

All times are GMT -4. The time now is 08:53.