I Dropped the −1/2 and the Viscosity Came Back Six Times Too Large — the Δt/2 Left Behind by LBM's Discretisation
·6 min read
One trapezoidal integration and one change of variables leave a Δt/2 in three separate places: the viscosity, the velocity, and the stress. A scalar ODE and a D2Q9 lattice measure all three.
I Plugged in Pressure Directly and a Still Interface Started to Shiver — Two Forms of Nonideal LBM Forcing
·6 min read
When a van der Waals fluid is solved with lattice Boltzmann, putting pressure p in the force term versus chemical potential mu agrees in the continuum but splits on the lattice.
Where Half the Force Goes in LBM — Four Forcing Schemes and 1−1/(2τ)
·9 min read
Comparing lattice Boltzmann body-force schemes and pinning down the half-force correction