Flow-induced vibration characteristics of pivoted cylinders with splitter-plates

Figures & data

Figure 1. Schematic of experiment apparatus.

Table 1. Structural properties of test cylinders with splitter-plates.

Splitter-plate length l/D	M*	I*	Angular stiffness kθ [N m/°]	fn-air [Hz]
0 (i.e. bare cylinder)	1.42	0.75	0.18 < kθ < 1.00	0.51
0.5	1.61	0.71		0.56
1.0	1.50	0.65		0.52
1.5	1.56	0.61		0.52
2.0	1.63	0.56		0.53
2.5	1.71	0.50		0.55
3.0	1.88	0.47		0.55

Figure 2. Experiment arrangement of the pivoted circular cylinder.

Figure 3. Definition schematic for normalized angular excursion of the pivoted cylinder.

Figure 4. Vibration response of pivoted cylinder without splitter-plate.

Figure 5. Frequency response of pivoted cylinder without splitter-plate.

Figure 6. Vibration responses of pivoted cylinder with splitter-plates l = 0.5D, l = 1.0D, l = 1.5D and l = 2.0D.

Figure 7. Vibration responses of pivoted cylinder with splitter-plates l = 2.5D and l = 3.0D.

Figure 8. Frequency responses of pivoted cylinder with splitter-plates of various lengths. (Note: f/f_n axis truncated at f/f_n = 1.5 to aid clarity. Thus, a number of the no splitter-plate data points only are absent).

Figure 9. Average oscillation frequency of each splitter-plate through-out U_r > 10. Note: Upper and lower dashes are offset by 1 standard deviation.

Figure 10. Linear trend-line fits to angular excursion of pivoted circular cylinder with attached N-R splitter-plates l = 0.5D, l = 1.0D, l = 1.5D and l = 2.0D.

Table 2. Galloping onset-reduced-velocity (U_r-critical) for cylinders with splitter-plates.

Splitter-plate length l/D	0.5	1.0	1.5	2.0	2.5	3.0
Ur-critical	4.5	6.5	9.0	9.2	10.5	13.5