Abstract:A scheme for implementing one of the widely used absorbing boundary conditions (ABCs)—Multi-Transmitting Formula (MTF) is proposed by combining MTF into the control equation of the interior nodes adjacent to the artificial boundary. Compared with the original scheme, the new one improves not only accuracy of the boundary condition, reduces the computational domain, but also reveals clearly a relation between the order of truncation error of the ABC and the extended mesh solution, which is commonly used as a benchmark to test ABCs. Limitation is then clarified for improving accuracy of numerical simulation of wave motion via increasing the accuracy order of an ABC. The performance of the new scheme, original one and Givoli-Neta ABC are finally compared via numerical examples concerning a semi-infinite wave guide, and resulted in that the first scheme is better than the other two.