Abstract
Numerical acoustic analysis methods using the immersed boundary method can simulate the acoustic characteristics of structures with curved or sloping surfaces using cubic cells by providing estimates obtained from the boundary conditions on a cubic grid in the vicinity of the object boundary. Numerical analysis is possible even when the boundaries of the object and the lattice do not coincide, which has the advantage of allowing simulation when the object is moving. The numerical accuracy of the immersed boundary method when applied to acoustic analysis has not been fully investigated. In this paper, we investigate the accuracy of the immersed boundary method by numerically simulating the case where a cylinder is placed in a two-dimensional sound field. The directional characteristics of sound pressure and error rate as well as the root-mean-square error rate were calculated. The numerical results using the immersed boundary method showed almost the same characteristics as the analytical solution. Under the conditions of this paper, the calculation accuracy was found to be equivalent to that of the numerical results using the cubic grid. In the future, we plan to investigate the possibility of improving the accuracy of the difference scheme.
