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


Geometry
---------


.. image:: images/1000312400003132000010F3F9BB25D640E5B0FC.svg
    :width: 634
    :height: 218


.. _RefImage_1000312400003132000010F3F9BB25D640E5B0FC.svg:

:math:`L=50m`

:math:`{R}_{i}=1m`

:math:`{R}_{e}=1.1m`

:math:`C`: pivot point of the external structure


Material properties
------------------------

Fluid: density :math:`{\rho }_{g}=1000\mathrm{kg}/{m}^{3}` (water).

Structure: :math:`{\rho }_{s}=7800\mathrm{kg}/{m}^{3}`; :math:`E={2.10}^{11}\mathrm{Pa}`; :math:`\nu =0.3` (steel).


Boundary conditions and loads
-------------------------------------

Fluid:


* to simulate the permanent flow, a normal speed of :math:`–4m/s` is imposed on the fluid inlet face (by thermal analysis, a normal heat flow equivalent to —4 is imposed),


* to calculate the fluid disturbance caused by the movement of the Dirichlet external cylinder at a fluid node.

Structure:

the external cylinder is subjected to a displacement of the type

.. image:: images/Object_9.svg
    :width: 634
    :height: 218


.. _RefImage_Object_9.svg:

at the nodes of the mesh of this cylinder.