2026 Volume 18 Pages 37-40
We investigate an exact solution of a nonlinear coupled advection equation in a volume-preserving system. The Hamiltonian of the system is obtained by reinterpreting a Poincaré invariant as the Hamiltonian. Hamilton’s equations of motion yield a nonlinear coupled advection equation. We also discuss properties of the nonlinear coupled advection equation related to the exact solution, including constants of motion.