ORTHOGONALITY OF WET MODES IN COUPLED VIBRATION

The orthogonality property of wet modes for arbitrary storage vessels filled or partially filled with compressible fluid is investigated by means of Love's thin shell equations and a linear potential flow theory. The proof shows that the wet modes do possess the orthogonality property for all kinds of fluid-filled tanks with zero boundary energy conditions when incompressible fluid is considered and the effect of free surface waves is neglected. It is pointed out that there is another kind of orthogonality relationship among wet modes when a compressible fluid is contained or (and) the effect of the free surface waves is considered. © 1991.