ON THE ADDED MASS AND DAMPING OF PERIODIC ARRAYS OF FULLY OR PARTIALLY POROUS DISKS
✍ Scribed by B. MOLIN
- Book ID
- 102591083
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 195 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0889-9746
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✦ Synopsis
In"nite and periodic arrays of porous disks are considered, in oscillatory #ow perpendicular to their planes. This con"guration is of interest for the o!shore oil industry, for instance to be used as dampers to reduce the heave motion of truss SPAR platforms. The hydrodynamic problem is solved by the method of matched eigenfunction expansions, under the assumptions that losses of head, proportional to the square of the traversing velocities, occur at the disks, and that potential #ow theory is applicable. Added mass and damping coe$cients are derived, as functions of the relative spacings between the disks, and of the parameter (A/a) (1! )/(2 ), where A is the #ow motion amplitude, a the disks radii, the porosity, or open-area ratio, and a discharge coe$cient, close to 0.5. Results are also given for disks that are partially porous, from their axis to some radial distance. The practical applicability of the obtained results is discussed.