Abstract: In order to carry out aerodynamic analysis with the FLUENT software and constant averaged acceleration Newmark method on dynamic mesh, the algorithm in the Newmark method needs to be changed due to the limitation of the data transfer mode. For the validation of this modification, numerical tests were simulated to show the deficiency in the algorithm. Based on these tests, we propose a hypothesis that numerical damping is introduced by the algorithm. This assumption was proved by mathematics method, and theoretical formula was provided to calculate the numerical damping. The effectiveness of this formula was validated by calculating numerical dumping in a test and calibrating the algorithm with the calculated numerical dumping. Moreover, this formula was applied to some engineering applications.