An extended lattice Boltzmann (LB) equation was developed for the simulatio
n of the phase-change problem governed by the heat conduction equation inco
rporated with enthalpy formation. Mathematical consistency between the prop
osed extended LB equation and the governing equation was accomplished by th
e Chapman-Enskog expansion. Illustrative examples include one-dimensional h
alf-space melting and solidification as well as two-dimensional solidificat
ion in a corner. Phase change at a single temperature and with a mushy zone
are both demonstrated. Two types of boundary condition, prescribed tempera
ture and prescribed heat flux, are considered in the illustrative examples.
Different thermal diffusivities in the separated phases/zones are accompli
shed through varying the relaxation times in the LB equation. All numerical
results obtained by the present scheme agree very we with previous analyti
cal or numerical results in the literature.