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

Parameter setting

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 5, 2019, 04:11
Default Parameter setting
  #1
New Member
 
Join Date: Jan 2019
Posts: 7
Rep Power: 7
Christina123 is on a distinguished road
Hello, I want to ask you some questions:
1. I want to define the EGR rate by the species of the intake air. May I define it in the“ boundary→inflow→species boundary conditions”, or define it in the“ region and initialization→intake→species”?
2. Now I don't have cylinder pressure data. Can I use torque calibration instead of cylinder pressure calibration?
3. (★) Since a large part of the soot is oxidized in the later stage of combustion, so, is the soot quality in the cylinder the same as the soot quality emitted by the engine when the exhaust valve is opened?If there is an error, is the error large ? I mean, is there still a part of the soot that will be oxidized after the exhaust valve is opened? So how do I accurately view the soot quality of the engine in the CONVERGE software?
Thank you very much. Looking forward to your reply.
Christina123 is offline   Reply With Quote

Old   February 7, 2019, 17:32
Default
  #2
Senior Member
 
nitesh.attal's Avatar
 
Nitesh Attal
Join Date: Sep 2017
Location: Convergent Science, Northville MI
Posts: 113
Rep Power: 8
nitesh.attal is on a distinguished road
Quote:
Originally Posted by Christina123 View Post
Hello, I want to ask you some questions:
1. I want to define the EGR rate by the species of the intake air. May I define it in the“ boundary→inflow→species boundary conditions”, or define it in the“ region and initialization→intake→species”?
2. Now I don't have cylinder pressure data. Can I use torque calibration instead of cylinder pressure calibration?
3. (★) Since a large part of the soot is oxidized in the later stage of combustion, so, is the soot quality in the cylinder the same as the soot quality emitted by the engine when the exhaust valve is opened?If there is an error, is the error large ? I mean, is there still a part of the soot that will be oxidized after the exhaust valve is opened? So how do I accurately view the soot quality of the engine in the CONVERGE software?
Thank you very much. Looking forward to your reply.

1) Yes, you can define them under boundary→inflow→species boundary conditions. Now the simulation may also be initialized with appropriate quantity of EGR composition in the cylinder region but passive EGR in the subsequent engine cycles will be predicted by CONVERGE.


2) Using CONVERGE you can calculate the in-cylinder pressure and post process (using CONVERGE Studio) to get IMEP/torque for comparison with experimental data. Note that this post process is a calculation of area under the curve which may be same for two completely different curves, thus we recommend you to compare the pressure trace from the experiment with CONVERGE results.


3) If you are measuring soot in the exhaust near the engine cylinder then you can compare with EVO soot values but if the experimental measurement is further downstream in the exhaust and you expect soot oxidation while the gases transfer to the measurement point, we recommend you to include this portion of the exhaust in your computational domain and ensure combustion and emission modeling is active in these regions. Furthermore, we recommend you to start with compare the soot trends as getting the absolute values is often difficult (for many reasons, such as soot is modeled as gas in the simulation but in reality is solid particles)
__________________
Nitesh Attal
Principal Engineer | Applications
CONVERGECFD
nitesh.attal is offline   Reply With Quote

Reply

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
[ICEM] Setting Shear Parameter on ANSYS ICEM yeongjia ANSYS Meshing & Geometry 0 July 11, 2018 04:02
Negative Volume Expert Parameter awesim CFX 18 July 17, 2017 09:05
Question on running CFX simulations in workbench parameter set table Anna Tian CFX 0 September 20, 2014 02:51
Setting BC parameter values for a buoyantBoussinesq run NJG OpenFOAM Running, Solving & CFD 0 March 5, 2013 12:19
compile errors of boundary condition "expDirectionMixed" liying02ts OpenFOAM Bugs 2 February 1, 2010 21:11


All times are GMT -4. The time now is 08:29.