Mysterious Heat Formation in Two-Phase Advection-Diffusion System

Hi, the system I’m working with consists of two phases, namely polymer and filler, and two lattices. In both lattices, there are adiabatic temperature boundaries on the left and right sides, as well as some area of space adjacent to each boundary—in these spaces all cells are attributed AdvectionDiffusionRLBdynamics. In between these two spaces (in the center of the system) is where there is polymer and filler. In the first lattice, the polymer has AdvectionDiffusionRLBdynamics and the fillers (dispersed randomly or arranged in lines) are BounceBack particles. In the second lattice, it is the opposite. I run both lattices at the same time, updating each lattice with the changes in temperature from the other lattice, and doing some interlattice updates and calculations. However, one issue I’ve noticed is that in the beginning of the simulations—before I introduce any heat pulse—is that some extra heat seems to be produced seemingly from nowhere. Right near the boundaries between the filler particles and the polymer particles, some, although not much, heat is produced. Where is this heat coming from?

The other issue is that once the heat pulse has been introduced and the system reaches it’s theoretically maximum temperature, the total heat in the system (summed densities of each particle) continues to increase over time. I’m confused about this, since I thought the RLBdynamics would stabilize this kind of situation. Is there a fix?

Nevermind this post; I’ve realized that it’s not heat formation, but simply part of the interlattice reaction. In other words, what’s happening should happen.

Well actually, just don’t mind the first part of the post. The total heat problem is still an issue.