Page 304 - Introduction to Naval Architecture
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VIBRATION, NOISE AND SHOCK 289
Figure 11.6 Cy values
Figure 11.7 C^ values
Three dimensional flow
The work of Lewis and others was based on long cylinders oscillating.
Under these conditions it is reasonable to assume that the flow is two-
dimensional in the section in the plane of motion. For a ship's hull the
flow will be three-dimensional because of the variation in section shape
along the length. Also away from the nodes the displacements are
rather greater than assumed in uniform oscillations and there will be
more movement of water. The overall effect of the three-dimensional
flow is to reduce the virtual added mass per unit length. A three-
dimensional added virtual mass factor, J is used, / being the ratio of the
