Propeller Excitation of Longitudinal Vibration Characteristics of Marine Propulsion Shafting System

Table 2

Calculated stiffness and damping of oil film based upon equivalent viscosity and variable viscosity.

Shafting rotating speed (rpm)	40	60	80	100
Stiffness (×10^9 N/m)
Variable viscosity	0.59	1.66	3.38	6.06
Equivalent viscosity	0.63	2.09	4.51	7.80
Damping (×10^8 N/m)
Variable viscosity	1.94	3.63	5.43	7.90
Equivalent viscosity	2.83	9.20	16.14	22.32