Level set method---reinitiallization and boundary conditions

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

 September 4, 2015, 04:56 Level set method---reinitiallization and boundary conditions #1 Senior Member   Freedom Join Date: May 2014 Posts: 209 Rep Power: 12 Hello, friends, Now I use level set method to simulate the premixed flame. However, I encounter two problems as follows, About the reinitiallization process : I use Sussman's method (1994) to reinitialize the level set field to enforce the level set to sign distance function. I solve the reinitialization equation using the level set field as the initial field and then impose this reinitialized level set field to the initial level set field. About the boundary conditions for level set equation and reinitialization equation. I use zeroGradient boundary condition for both fields and for all of the patches. But I privately think that the fixedGradient boundary condition should be implemented to the reinitialization equation. Because the sign distance function should be satisfied. PS: The initial level set field is initialized with the funkySetFields tool to meet the sign distance function. I am not sure whether the methods described above are right. But the problem is that the zero level set surface does not move a little!!!! Could anyone give me some suggestions? Many thanks. Every idea is appreciated! Best, Wen

September 13, 2015, 23:02
#2
Senior Member

Freedom
Join Date: May 2014
Posts: 209
Rep Power: 12
Now I figure it out that if I do not use the reinitialization step, the zero level set does can capture the flame front at the first times. However, the front will biased as the time proceeds.

When the initialization step is implemented into the level set process, the zero level set moves with a irregular routine. The reinitialization step code is as follows:
Quote:
 fvScalarMatrix GReinitialEqn ( fvm::ddt(GEReinitial) == signG0*(scalar(1.) - mag(fvc::grad(GEReinitial))*dimChange1)*dimChange2 ); GReinitialEqn.solve(mesh.solver("GRe"));
Any one could give me some hints what's wrong with the reinitialization step?

Best regards,
Wen

February 28, 2018, 11:43
0 level set
#3
Member

Yuanwei Cao
Join Date: Jun 2017
Location: Munich,Germany
Posts: 54
Rep Power: 8
Quote:
 Originally Posted by wenxu Now I figure it out that if I do not use the reinitialization step, the zero level set does can capture the flame front at the first times. However, the front will biased as the time proceeds. When the initialization step is implemented into the level set process, the zero level set moves with a irregular routine. The reinitialization step code is as follows: Any one could give me some hints what's wrong with the reinitialization step? Thank you in advance! Best regards, Wen
It is a long time. May I ask you how to use funkySetFields to initialize the yero level set?

Best Regards
CYW