5.5 Simulation Deflection Results
Deflection results are useful in predicting cage behavior. Presented here are
qualitative results for a specific material case and maximum deflection results for each
material case. Numeric sign associated with deflection is related to the previously
defined cage coordinate system. For diameter changes, a negative change indicates a
decrease in diameter, while a positive change indicates an increase.
5.5.1 Qualitative Deflection Results
Figure 5.10 shows deflection data of the net cage x-diameter deflection for a
representative case of the VF-800 tested in top-flow at a water speed of one knot at
various cage diameters. Deflection results are identical for the cage y-diameter based on
the symmetry of the geometry and loading. Cage diameter change has a qualitatively
linear trend for the top-flow cage loading. Figure 5.11 shows data of the maximum z-
deflection for the same representative case. The data represents the maximum bending
deflection occurring in each tube and has an expected qualitatively decreasing parabolic
trend as cage size is increased.
Figure 5.12 shows cage y-diameter deflection data for the VF-500 representative
case, but in side-flow. As seen in the geometry deformation of the side flow cage, the
cage y-diameter decreases drastically. No clear trend is visible in the smaller x-diameter
deflection. This is because the multiple bending modes largely affect the x-diameter
cross members and occur differently in each cage size. X-diameter cage deflections must
be considered on a case by case basis for side-flow.