有限要素法による室内音場解析におけるCOCG法の収束性

抄録

An iterative method, namely COCG (Conjugate Orthogonal Conjugate Gradient) method, is applied to finite element sound field analysis of rooms. First of all, convergence of COCG method applied to finite element sound field analysis of three rooms is investigated from the following viewpoints: (1) sound source frequency; (2) absorption coefficient of a wall; and (3) sound source location. The results show that: (1) A lower frequency engenders faster convergence of COCG method in all rooms. (2) A higher absorption coefficient engenders faster convergence of COCG method except for a small cubic cavity. (3) Convergence of COCG method is affected by the sound source location in rectangular rooms. As an application of the results, we propose efficient parallel computation method using the relationship between frequency and convergence of COCG method. In addition, the results obtained by the numerical experiments for the three rooms are validated on a large-scale room.