Reference problem
=====================


Geometry
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It is a parallelepiped with a length :math:`1.m` following :math:`x`, a width :math:`0.2m` following, and a width following :math:`z` and a depth :math:`0.1m` following :math:`y`.


Material properties
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* :math:`\rho =1.3\mathit{Kg}/\mathit{m³}`


* :math:`c=343.+0.jm/s`


Boundary conditions
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The speed imposed on the group 'ENTREE' is :math:`0.014+2.jm/s`.

The impedance imposed on the 'SORTIE' group is :math:`445.9+3.jNs/m` *.*

The pressure imposed on the 'NO600' node is :math:`1.+3.jN/{m}^{2}` *.*

The pressure imposed on the 'NO500' node is :math:`1.+3.jN/{m}^{2}` *.*