Natural convection in 3D irregular domain

All spatial operators are discretized using RBF-FD with $r^3$ PHS radial basis functions, augmented with monomials up to order $2$, with the closest $25$ nodes used as a stencil. For the time discretization time step $\Delta t=10^{-3}$ was used for all cases. Nodal distance $h=0.01$ is used for simulations in 2D and $h=0.25$ for simulations in 3D. Boundaries with Neumann boundary conditions are additionally treated with ghost nodesGhost nodes (theory).