Furthermore, a parametric study is performed to investigate the influence of the mass and connecting stiffness of the attached pipes on the mean-square velocity of the hull.
Then, its normal mean-square velocity can be expressed as
The normal mean-square velocity which embodies the distribution of velocity on the hull can be the representation of spatial averaging results on the surface of the hull.
and the physical quantities such as mean-square velocity and power flow can be expressed as
When b represents mean-square velocity, [b.sub.ref] = [([10.sup.-9] m/s).sup.2]; when b represents power flow, [b.sub.ref] = [10.sup.-12] W.
Figure 11 shows that the normal mean-square velocity of the hull surface varies with the attached pipes mass.
Figure 12 shows the normal mean-square velocity of the hull surface varies with the connecting stiffness.
Caption: FIGURE 4: Comparison of the synthesized FRFs and the simulated results excited by single-sourced single-direction force: (a) displacement of the lower isolator in z-direction; (b) displacement of the lower isolator in %-direction; (c) displacement of point between hull and attached pipes in z-direction; (d) mean-square velocity of hull surface.