Abstract：The numeric simulation of wave equation always suffers from the dispersion effect.Using finite-element simulation of acoustic wave equation, the consistent mass matrix plays an opposite role to lumped mass matrix in dispersion error,consistent mass matrix makes the dispersion error to be ahead of the true signal,while the lumped mass matrix makes it to fall behind.Using linear combination of two mass matrixes can effectively suppress numeric dispersion.The velocity has little influence on combining coefficient,and optimal combining coefficient is about 0.5 when the velocity is in 2500~4000 m/s.Using the method for suppressing numeric dispersion is characteristics of neither adding extra computational efforts nor leading the algorithm to complex,which can be adaptive to velocity-changing model.
