Lamrad, Haroun2021-07-122021-07-122021http://dspace.univ-msila.dz:8080//xmlui/handle/123456789/24857We consider the 2-dimensional wave equation in non-cylindrical domains, i.e. domains depending on time. We rst use a penalization method depending on a parameter ". The obtained problem is a wave equation, posed in a cylindrical domain, with a penalized weak damping term. If the domain is expanding with time, we show that the solution of the penalized problem converges to the solution of the original problem, as " ! 0. Finally, to obtain a numerical approximation of solutions, we combine this penalization method with an explicit nite di erences approach.enWave equation, non-cylindrical domains, penalization method, nite di erences.Thesis