1. But

Define the characteristics necessary for the dynamic study of a flowing structure.

By choosing one of the key factors, the user specifies the type of « flow structure » configuration studied: bundle of tubes under transverse or axial flow, control cluster, co-axial shells. Depending on the type of configuration, the data provided makes it possible to carry out downstream:

• a fluid/structure coupling study: estimation of fluid-elastic force coefficients and calculation of new modal parameters of the structure using the operator CALC_FLUI_STRU [U4.66.02],

• the projection on a modal basis under flow of one or more turbulent excitations defined by their spectral density (s): operators DEFI_SPEC_TURB [U4.44.31] and PROJ_SPEC_BASE [U4.63.14]. It is then possible to calculate the response of the structure to the turbulent excitation, in time and in frequency.

The « DEFI_FLUI_STRU » operator produces a type_flui_stru concept intended to be used downstream by operators FONC_FLUI_STRU [U4.35.02], CALC_FLUI_STRU [U4.66.02] or, indirectly, PROJ_SPEC_BASE [U4.63.14].