3. Modeling A

3.1. Characteristics of modeling

Modeling includes:

• structural side:

336 shell elements DKT modeling the sphere 1,

6 discrete elements of type K_ TR_L (modeling DIS_TR) modeling the six springs connecting sphere 1 to the massif,

• fluid side:

672 THER_FACE3 thermal elements modeling the fluid/structure interface,

39 445 THER_TETRA4 thermal elements modeling the fluid.

3.2. Characteristics of the mesh

Number of meshes and types: 672 TRIA3 meshes, 39,445 TETRA4, 6 SEG2

3.3. Tested values

Identification	\(\mathrm{Hz}\) Reference
Fashion No. 1	3.1172
Fashion No. 2	3.1183
Fashion No. 3	9.2727
Fashion No. 4	9.8267
Fashion No. 5	22.4400
Fashion No. 6	30.3295

3.4. notes

The difference in the last two natural frequencies is explained by a non-symmetry of the mesh of the fluid/structure (thermal) interface with respect to that of the first. The mesh of the fluid/structure interface (thermal elements) of the second sphere cannot be deduced exactly from that of the first by rotating nautical angles of \(90°,0°,90°\).