[Kislay]

Dear Sir,
I am running close cycle simulation (IVC to EVO) of a diesel engine(Twin cylinder diesel engine; 909cc) for dual fuel case by using methane and diesel. When I am not using crevice model, the in cylinder pressure plot had slight mismatch with experimental pressure plot (at expansion side) and we included crevice model to bring it closer to experimental plot for validation. But when I am adding crevice model in converge, the pressure plot is not matching as peak pressure is coming very low as compared to experimental/without crevice model even after entering correct crevice dimensions as specified by engine. Why is this happening?

I have not added crevice geometry in full geometry, but I am adding crevice model in converge. Is this correct way of adding crevice ?

[usamaubk]

Originally Posted by Kislay

Dear Sir,
I am running close cycle simulation (IVC to EVO) of a diesel engine(Twin cylinder diesel engine; 909cc) for dual fuel case by using methane and diesel. When I am not using crevice model, the in cylinder pressure plot had slight mismatch with experimental pressure plot (at expansion side) and we included crevice model to bring it closer to experimental plot for validation. But when I am adding crevice model in converge, the pressure plot is not matching as peak pressure is coming very low as compared to experimental/without crevice model even after entering correct crevice dimensions as specified by engine. Why is this happening?

I have not added crevice geometry in full geometry, but I am adding crevice model in converge. Is this correct way of adding crevice ?

Hello, I think you dont need to add crevice into the geometry itself (i mean in the design), Defining it in CONVERGE itself is enough. Besides to get the peak pressure you can play with Compression ratio a bit, in my opinion....as adding crevice results in loss in pressure which can be somehow compensated by increasing CR....Thanks

[arajendran]

Originally Posted by Kislay

Dear Sir,
I am running close cycle simulation (IVC to EVO) of a diesel engine(Twin cylinder diesel engine; 909cc) for dual fuel case by using methane and diesel. When I am not using crevice model, the in cylinder pressure plot had slight mismatch with experimental pressure plot (at expansion side) and we included crevice model to bring it closer to experimental plot for validation. But when I am adding crevice model in converge, the pressure plot is not matching as peak pressure is coming very low as compared to experimental/without crevice model even after entering correct crevice dimensions as specified by engine. Why is this happening?

I have not added crevice geometry in full geometry, but I am adding crevice model in converge. Is this correct way of adding crevice ?

Hi Kislay,


Like Usama mentioned, implementing the crevice model through CONVERGE settings is sufficient; you do not need to make any changes to the geometry. Please refer to the CONVERGE manual to make sure you are implementing it right.



You may also refer to Crevice model details (slide 28) in the 'ICE01 pistonvalve' training resource found at Downloads-> Converge 3.0-> Training materials->Converge for Internal Combustion Engines-> Presentation Slides at the Converge hub (https://hub.convergecfd.com/login). You will get free access to it once you make an account there.


If you can provide further context on how you are setting up the model here, that would be helpful in suggesting further improvements on your setup too.