Initialize Pressure Field in Lattice Boltzmann Method with pressure-based equilibrium

julia.p · November 13, 2017, 07:12

I am currently learning about Lattice Boltzmann Method for incompressible Navier-Stokes Equation. Specifically speaking about free surface waves from the following paper : click here

It used ILBGK pressure-based equilibrium distribution function by Guo.

Basically I understand the overall algorithm of method used in that paper, but I'm confuse how to initialize the distribution function using this model, especially the pressure field which is usually unknown.

I want to simulate the propagation of solitary wave over a flat bottom. From the references I've read so far, initial and boundary condition usually state in velocity while the pressure is unknown. I also read consistent initialization by Mei, but it seems it will lots of iteration. Other reference also say that the initial pressure can be found by solving the pressure-poisson equation by Gauss-Seidel Method. I've tried use the latter, but by using different initial pressure at iterative method, I get different result or is it okay to initialize the pressure by constant value? or am I missing some important concept about LBM?

Thanks in advanced

:

arjun · November 13, 2017, 18:49

if i remember correctly the pressure is result of density and density is equation to sum of probability F functions.

In case of incompressible formulations i am not sure how it would work.

November 13, 2017, 07:12	Initialize Pressure Field in Lattice Boltzmann Method with pressure-based equilibrium	#1
julia.p New Member Julia P. Join Date: Nov 2017 Posts: 1 Rep Power: 0	I am currently learning about Lattice Boltzmann Method for incompressible Navier-Stokes Equation. Specifically speaking about free surface waves from the following paper : click here It used ILBGK pressure-based equilibrium distribution function by Guo. Basically I understand the overall algorithm of method used in that paper, but I'm confuse how to initialize the distribution function using this model, especially the pressure field which is usually unknown. I want to simulate the propagation of solitary wave over a flat bottom. From the references I've read so far, initial and boundary condition usually state in velocity while the pressure is unknown. I also read consistent initialization by Mei, but it seems it will lots of iteration. Other reference also say that the initial pressure can be found by solving the pressure-poisson equation by Gauss-Seidel Method. I've tried use the latter, but by using different initial pressure at iterative method, I get different result or is it okay to initialize the pressure by constant value? or am I missing some important concept about LBM? Thanks in advanced : Last edited by julia.p; November 13, 2017 at 18:51.

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November 13, 2017, 18:49		#2
arjun Senior Member Arjun Join Date: Mar 2009 Location: Nurenberg, Germany Posts: 1,273 Rep Power: 34	if i remember correctly the pressure is result of density and density is equation to sum of probability F functions. In case of incompressible formulations i am not sure how it would work.