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Séminaire ISTerre
Introduction to perturbation theory of acoustic fields using operators
jeudi 16 juin 2022 - 15h00
Alberto Giuliano Albo - Istituto Nazionale di Ricerca Metrologica, Torino, Italia---
Since only a very limited number of physical problem can be solved exactly, in the real world, the solutions are often found using perturbation methods. Those methods assume the problem can be defined starting from the parametrisation of a similar system that can be solved and then the solution is built by modifying the obtained zero-approximation using converging series. Since the calculations of the series expansion is usually difficult a complete solution is not the scope of the process. When the problem is well posed, only the first two or three terms are needed to obtain approximations with accuracy comparable with that of the laboratory measurements. In this work, principles of a perturbation theory of acoustic fields based on operators is applied to simple examples like steady state acoustic fields when temperature gradient occurs or when simple geometrical imperfections alter the acoustic field.