Research On The Rapid Algorithm For Coupled Mode Method

In the light of the high precision of The Coupled Normal Mode (CNM), it is widely adopted as the criterion of the acoustic field computation in complex ocean environments. However, there exists a great mount of computations. The computing speed is not acceptable for practice, either. This paper focus on the problem mentioned above via researching the fast algorithm of solving the CNM amplitude equation.The paper starts from introducing the CNM, Parabolic Equation Method (PEM) and Ray Acoustics Method (RAM). Then the differential equations for solving CNM amplitude are obtained. The CNM-RAM model and CNM-PEM model for high speed normal mode solution are described in detail. Besides, the program for CNM-PEM numeric computation is developed on the Fortran platform. Its computation errors of transition loss in conditions of range dependent and independent are verified through comparison with benchmark problem. Reasons for errors are analyzed via comparing with the Couple07 results.