The Hardy–Pomeau–Pazzis (HPP) model is a fundamental lattice gas automaton for the simulation of gases and liquids. It was a precursor to the lattice Boltzmann methods. From lattice gas automata, it is possible to derive the macroscopic Navier-Stokes equations.[1] Interest in lattice gas automaton methods levelled off in the early 1990s, due to rising interest in the lattice Boltzmann methods.[2]
It was first introduced in papers published in 1973 and 1976 by Jean Hardy, Yves Pomeau and Olivier de Pazzis,[3] whose initials give the model its name. The model can be used as a simple model for both the movement of gases and fluid.[4]