[Sarthak876]

Hi,
My goal is to Generate some random points in space which I have done. But I am not able to figure out how not two points overlap in space(mainly not two points should be in vicinity of other till raidus =1). How to do it !!!

[ghorrocks]

What are the points for? Monitor points? particle seed points? Something else?

[Sarthak876]

Originally Posted by ghorrocks

What are the points for? Monitor points? particle seed points? Something else?

The points basically represent particles with raidus 1 unit.

[ghorrocks]

Are they seed points for a particle tracking model?

[Sarthak876]

I dont know what is Particle tracking model. I am trying to generate model in which I generate Random particle in confined space and then by some potential they interact,potential is only position dependent there should be a finite distance between every particles and that is 1 unit in any direction.

I dont know how to generate coordinates of Particles such that no two particles are in vicinity of each other. Please help

[ghorrocks]

Some explanation of what you are doing would help.

Are you generating these points in the solver, post processor, a solid modelling package or the mesher?

How do the points interact? Do they interact with a fluid? If so then how?

[Sarthak876]

They are interacting via Lenard-Jones potential,with each Iteration there position is changed but with is the confined Volume !! Suppose it as like a gas molecules in box but here they interact with L-J potential.

[ghorrocks]

The L-J potential is an atomic scale effect. CFX cannot model atomic scale effects. It sounds like you are using the wrong software.

[Sarthak876]

I am writting CODE in fortran and then plot my points in gnuplot !!

And I think I know the solution now what you do is generate 1000 or whatever no of particles you want to generate and then calculate distance btw each pair and if it is less than your raidus of paricle or atom replace one of the particles one of the coordinate and it may happen now where you have putted your particle it is in vicinity of any other particle so again do the above thing untill tou find a place where there is no particle in its vicinity.

here's my code for it


!================================================= ===============================================!
!========================ELIMINATING OVER LAPPING OF POINTS======================================!
!================================================= ===============================================!
subroutine Eliminate_overlap(n,x,y,z,sizee)
implicit none
integer::n
real::x(n),y(n),z(n),sizee
integer::i,j
real::xr,yr,zr,dis
integer::m


do i=1,n-1
do j=i+1,n
xr=(x(i)-x(j)) !Distance of ith particle from all particles in X direction
yr=(y(i)-y(j)) !Distance of ith particle from all particles in Y direction
zr=(z(i)-z(j)) !Distance of ith particle from all particles in Z direction

dis=( ((xr)*(xr))+((yr)*(yr))+((zr)*(zr)) )**(0.5)

if ((dis)>1) then
else
if ((dis)<=1) then
call replace(i,j,x,y,z,n,sizee)

end if
end if
end do
end do

return
end subroutine

subroutine replace(i,j,x,y,z,n,sizee)
implicit none
integer::n
real::x(n),y(n),z(n),sizee
integer::i,j
REAL :: r
CALL init_random_seed()
CALL RANDOM_NUMBER(r)
x(i)=(r*sizee)
call Eliminate_overlap(n,x,y,z,sizee)
return
end subroutine
!================================================= ===============================================!

Thanks for you help bro/sis, if there is any problem in this algorithm please tell me.

[ghorrocks]

If you are not using CFX then why are you posting on the CFX forum?