Abstract
Lattice Boltzmann model with a double distribution functions are used to simulate thermal vapor-liquid two-phase flow. In this model, the single component multi-phase lattice Boltzmann model proposed by Zhang and Chen is used to simulate the fluid dynamics. The internal energy is simulated by using a energy distribution functions. By coupling the fluid dynamics and internal energy field through a suitably defined density term, the thermal gas-liquid phase flows are simulating. Numerical results on phase separation show the coexistence curves of numerical simulations are in good agreement with the theoretical predictions for the density of gas-liquid phase, and the internal energy of gas is higher than the internal energy of liquid at the same reduced temperature.