Screening of Slow Speed Marine Diesel Propulsion Shafting Design Space

Original scientific paper In this paper a systematic exploration of a typical two-stroke slow speed marine diesel propulsion shafting design space is performed. First, a set of the four most influential design parameters is defined, consisting of shafting stiffness, propeller, turning wheel and tuning wheel mass moments of inertia. Then, a full set of 625 design points is defined. For each design point a complete torsional vibration analysis has been performed, and the three most significant results were collected. These are the first torsional natural frequency, crankshaft peak torque and shafting peak torque. Finally, the results are presented in three series of response surface diagrams. Furthermore, the ability of each system parameter to change the system response is analysed by using Saaty’s priority theory. The presented results provide better insight into the propulsion system torsional vibration behaviour and encourage designers to achieve a desired design solution already in the preliminary design phase. Although the key findings are related to the specific diesel engine only, it is believed that the presented behaviour is quite general and hence qualitatively applicable to a much broader range of the two-stroke slow speed diesel propulsion plants.