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-   -   Initialization by MAP files. (https://www.cfd-online.com/Forums/converge/240882-initialization-map-files.html)

XjtuBryant January 28, 2022 08:24

Initialization by MAP files.
 
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The MAP file is generated at Crank angle of 690. When the MAP file is used to initialize all regions, the profile of fuel film, liquid fuel and fuel vapor mass in the "Intake port Region" are different with that calculated by the simulation which generates the MAP file. Why? Initialization by MAP file is convenient for PFI engine because of fuel film dynamic. However, the above phenomenon indicates MAP file change the profile of fuel film mass. So i want to know the reason of this results and the solution. Thanks!:p

nitesh.attal January 28, 2022 08:35

Quote:

Originally Posted by XjtuBryant (Post 821175)
The MAP file is generated at Crank angle of 690. When the MAP file is used to initialize all regions, the profile of fuel film, liquid fuel and fuel vapor mass in the "Intake port Region" are different with that calculated by the simulation which generates the MAP file. Why? Initialization by MAP file is convenient for PFI engine because of fuel film dynamic. However, the above phenomenon indicates MAP file change the profile of fuel film mass. So i want to know the reason of this results and the solution. Thanks!:p



Mapping is performed on a grid that your simulation starts with.

AMR (if active) will generate cells after the first time step (2 and onward).

Now, the Map file contains data associated with AMR cells too so the effective number of cells the case has when you generated the map file is much larger than the case you are using the map file in (there is a loss of resolution because AMR cells are not present). In this situation CONVERGE maps the data in map file to the nearest grid point available in the mapped simulation. Thus the mapped field will look smeared.



A workaround is to have an embedding that lasts 1 or 2 timestep with a resolution equal to the finest resolution you have in the map file. This will ensure that the mapped data gets mapped without any smearing.



Let me know if that worked for you.


Also, take a look at the 3D files to compare the mapping filed to the mapped filed.


Thanks,

XjtuBryant June 15, 2022 23:24

Quote:

Originally Posted by nitesh.attal (Post 821177)
Mapping is performed on a grid that your simulation starts with.

AMR (if active) will generate cells after the first time step (2 and onward).

Now, the Map file contains data associated with AMR cells too so the effective number of cells the case has when you generated the map file is much larger than the case you are using the map file in (there is a loss of resolution because AMR cells are not present). In this situation CONVERGE maps the data in map file to the nearest grid point available in the mapped simulation. Thus the mapped field will look smeared.



A workaround is to have an embedding that lasts 1 or 2 timestep with a resolution equal to the finest resolution you have in the map file. This will ensure that the mapped data gets mapped without any smearing.



Let me know if that worked for you.


Also, take a look at the 3D files to compare the mapping filed to the mapped filed.


Thanks,

thank you very much, the way you recommended worked for me.


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