On the numerical approximation of high-frequency multiple scattering problems by circular cylinders

International audience ; The aim of this paper is to proposea numerical strategy for computing the solution of two-dimensional time-harmonicscattering problems at high-frequency. The scatterers are assumed to be circular leading thereforeto semi-analytical representation formulae of the scattered field through the solutionof a large linear system of equations. An adapted numerical solution is proposed, taking careof the special block Toeplitz structure of the matrix involved in the formulation. Thisyields large memory savings. Moreover, a specific preconditioned iterative and fastalgorithm is given and analyzed for computing the field scattered by general configurations.Several numerical experiments are presented to show the efficiency of the numerical method.