The iterative simulation equation set of high accuracy surface modeling

HASM3

is upgraded into HASM4 on the basis of numerical tests repeatedly in order to give a solution to the computing time problem of HASM3.The experimental results show that HASM4 has greatly shortened the computing time comparing with HASM3.With increase of total number of grid-cells in the computational domain

the computing time of HASM4 becomes shorter and shorter

which can be formulated by a function of negative power exponent.In the meanwhile

iteration times of HASM4 for reaching its convergence rectilinearly decrease with increase of total number of grid-cells in the computational domain

comparing with the ones of HASM3.HASM4 has not only shortened computing time

but also enhanced simulation accuracy

comparing with HASM3.