1. But

Project one or more turbulence spectra onto one (or more) modal basis (s). Spectra are defined by the operator DEFI_SPEC_TURB [U4.44.31]. The modal base (s) may or may be defined by:

• a melasflu-like concept produced by the operator CALC_FLUI_STRU [U4.66.02],

• a mode_meca concept produced by the operator CALC_MODES [U4.52.02],

• a list of concepts such as cham_no_depl_r corresponding to deformations.

Allows to calculate an interspectral matrix of generalized excitations for each defined modal base. If necessary, one option allows only autospectra to be calculated.

The product concept is of an interspectrum type.