Question

Mpemba effect. A countercurrent thermal exchange system spontaneously evolving and driven by the energy of the liquid would be an elegant solution.

Answer 1

A countercurrent thermal exchange system forms at the boundary surface. On the outside the heated air RISES to be replaced by more cold air. On the inside, the cooling liquid at the boundary FALLS, cycling through the center of the container. The system is uses the stored energy of the liquid to overcome the inertia of the liquid and the air. Countercurrent thermal exchange systems gain in efficiency with increased gradient. The greater the gradient, the more efficient the system and the sooner it develops. It also adds inertia to a greater amount of air mass which continues to cool the liquid as it sheds inertia even after the liquid cools. Am I on to something here?