Table 1: The first 24 coupled natural angular frequencies of the partially immersed beams in a viscous fluid. Comparison of frequency between FEM and present method.

Order Present FEM Difference

1 4.90 4.86 0.82
2 18.18 17.91 1.50
3 20.26 20.01 1.24
4 21.11 20.86 1.19
5 24.68 24.50 0.73
6 30.48 30.20 0.92
7 31.59 31.44 0.47
8 39.24 38.91 0.84
9 44.68 44.51 0.38
10 47.65 47.31 0.71
11 50.20 49.72 0.96
12 54.68 54.02 1.22
13 56.10 55.33 1.39
14 61.47 61.25 0.35
15 61.90 61.36 0.88
16 64.57 64.15 0.65
17 67.29 66.72 0.85
18 73.47 72.99 0.65
19 79.63 79.21 0.53
20 80.06 79.42 0.80
21 85.67 85.41 0.30
22 87.58 87.09 0.56
23 91.33 90.85 0.52
24 97.44 97.10 0.35