u4.25.01 Operator DEFI_FLUI_STRU# 1. But 2. Syntax 3. Operands 3.1. Keyword FAISCEAU_TRANS 3.2. Keyword GRAPPE 3.3. Keyword FAISCEAU_AXIAL 3.4. Keyword COQUE_COAX 3.5. Keyword INFO 4. Complements concerning configurations of the « bundles of tubes under transverse flow » type 4.1. Defining the characteristics of the beam 5. Complements concerning « coaxial cylindrical shells » configurations 5.1. Singular input pressure loss coefficients 5.2. Singular output pressure loss coefficients 6. Bibliography