Parameter setting
 

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)