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mas July 19, 2010 23:53

Incylinder dynamic mesh with volumetric reaction
1 Attachment(s)
Hi all,

I'm doing (volumetric reaction) methane-air combustion.
I'm using a 3D in-cylinder dynamic mesh with 0.005deg CA / timestep.
I set the mesh to update every timestep.
The calculation and the ignition start at TDC.
For the time being I'm using high temperature patching method to initiate the reaction.

I have problem only with the dynamic mesh.
The mesh doesn't change when I switched on the volumetric reaction.

I have performed several tests to verify this problem:
1. When I switched off the volumetric reaction, the mesh changes accordingly. Piston moving down and the volume increases.
2. When I switched on the volumetric reaction, the reaction occurred accordingly but the mesh doesn't change at all. Piston remains at TDC and volume constant.

The figure in this attachment is a cross-section of the combustion chamber at 37.4deg after TDC. The bottom wall is the (should-be-moving) piston with cavity. The volume remains constant as it is at TDC.

Am I missing something? Please help.
Any thought/comment/advice is appreciated.

Thank you.

mas July 22, 2010 22:15

Since there is no answer in this thread, I would like to rephrase my question.
Is Fluent capable of calculating 3D incylinder dynamic mesh with volumetric reaction?

kmpang March 5, 2011 07:26

Coupling of dynamic mesh and volumetric reaction
Dear Mas,

I have tested the coupling of dynamic mesh and volumetric reaction. Fluent is capable of calculating 3D incylinder dynamic mesh with volumetric reaction.

May I know,
1) what crank period value that you have used?
2) how do you simulate the ignition?

mas March 6, 2011 23:04

Dear kmpang,

Thank you for your reply.
FYI, I have abled to solve this problem quite some time ago.

My lesson learnt: Fluent cannot re-mesh if the piston displacement is extremely small. This limitation is caused by single precision calc., extremely small time-step/CA, or extremely low piston velocity.

MLAiroldi May 3, 2012 10:22

Meshing Internal Combustion Engines Simulation

I want mo make an alternative engine combustion simulation using ICEM and FLUENT but i don't know how to make the dynamic mesh using this two softwares. Can you guys help me out?

I just need to know how the procedure works, because I am already familiar with meshing process in ICEM.


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