As shown in Figure 22, it is clear that the dimensionless amplitude of the UMP with plate ([L.sub.p]/D = 1.0342) is much smaller than that of the bare UMP.
The dimensionless amplitude s of the UMP with plate and the bare UMP are 0.013508 and 0.847339, respectively.
As shown in Figure 23, the RMS of total lift coefficient is also reduced relative to the bare UMP by comparing the CFD simulation results with the optimization results (obtained from the BP neural network and genetic algorithm).
As shown in Figures 24 and 25, they are the vorticity cloud images of bare UMP and UPM with [L.sub.p]/D = 1.0342, respectively.
The overall can be seen in Figure 26(a), and the bare UMP's wake region pressure changes significantly.
Under the action of current flow, the UMP suspended in seawater will undergo vortex-induced vibration, so that it can lose its value.
In fact, qualitatively, the mixed SAGE composed of rotor offset and stator convex and concave deformation (especially the concave deformation) will actually bring in larger UMP than the mixed one indicated in the table.
This paper investigates the impact of different SAGE forms on the rotor UMP. The whole work is primarily carried out through the theoretical analysis and the numerical FEM calculation, together with some experiment studies.
(1) The occurrence of SAGE, no matter which kind it is, will bring in amplitude increments at each even harmonic component of the UMP and the rotor vibration, especially the 2nd harmonic component.
(2) Among the single SAGE types, the rotor offset has the most sensitive effect on the rotor UMP and vibration, while the stator ellipse deformation has the weakest impact.
(3) The mixed SAGE conditions composed of rotor offset and stator concave, stator convex, and stator ellipse deformation will induce a larger rotor UMP and drastic vibration compared to the single concave, convex, and ellipse deformation, but meanwhile a smaller rotor UMP and weaker vibration than the single rotor offset form.
For example, the stator ellipse deformation without a serious extent can be generally ignored due to the very tiny UMP induced by this kind of SAGE, while the rotor offset form needs careful modification work on the rotor to avoid further deterioration and potential damage.