2. Benchmark solution#
2.1. Calculation method used for the reference solution#
For the calculation of the added coefficients:
we show [bib1] that the added mass and damping coefficients depend on the permanent potential of the fluid velocities \(\stackrel{ˉ}{\phi }\) as well as on two fluctuating potentials \({\phi }_{1}\) and \({\phi }_{2}\): these potentials can be written in the case of the flexural movement of the plate [bib1]:
For the first mode:
For the second mode:
However, the added modal coefficients projected onto these flexure modes can be written as:
either:
Digital applications:
An added damping calculation was made which corresponds, for the given speed, to a damped vibratory behavior of the structure:
Speed \({V}_{0}\) to \(4{\mathrm{m.s}}^{-1}\)
The values of the mechanical system are:
The mass added by the flow is equal to:
The depreciation added is equal with \({V}_{0}=4{\mathrm{m.s}}^{-1}\):
The added stiffness applies with \({V}_{0}=4{\mathrm{m.s}}^{-1}\):
2.2. Benchmark results#
Analytical result.
2.3. Bibliographical references#
ROUSSEAU G., LUU H.T.: Mass, damping and stiffness added for a vibrating structure placed in a potential flow - Bibliography and implementation in the*Code_Aster - HP-61/95/064
BLEVINS R.D: Formulas for natural frequency and mode shape. Ed. Krieger 1984