Hello! I am using the Lattice Boltzmann method to simulate multiphase flow. The details are not important but the main drive behind multiple phases being simulated is interparticle forces. Now I am trying to visualise intuitively how such interparticle forces will cause a fluid to experience surface tension. As known, in 2d, this will ultimately cause the liquid phase to form a circle. Basically my suggestion is to take a square and then comparing a particle at the edge of the square with a particle at a corner of the square. Not forces are only considered due to neighbouring nodes on the mesh and the forces are attractive and dependent on nearby densities. My argument is that because these two particles will consider different forces the geometry has to change. This change will continue until it forms a circle because this is the only case where the forces are equal for all particles. Still I am having trouble visualising this myself. Although I can understand the forces experienced are different I am unsure as to how. A look at the figure might help to show what I am trying to accomplish. Any help would be appreciated. View attachment 19169 Red circles represent the two nodes under consideration and the yellow dots show the eight neighbouring needs which provide attractive forces based on the density at their positions.