Propulsion system simulations : Making the right choice for the application

The effective use of simulation for the design and analysis of propulsion systems, and for operator training of these systems, requires a clear definition of the simulation's intended purpose and expected results. Issues such as model fidelity, computational performance and data requirements must be carefully balanced against the development effort and costs. The relative importance of each of these factors can only be determined once the purpose and expected outputs from the simulation are known. Experience with some recent marine propulsion simulation initiatives has highlighted the need for clear definitions of model requirements, especially with regard to simulation fidelity and the use of physics-based models. Marine propulsion system simulations can be used for a variety of purposes ranging from machinery performance analysis through maneuvering and seakeeping analysis to equipment health monitoring studies. This wide range of applications, with differing requirements, provides an excellent forum for examining the influence of fidelity on simulation computational performance, data requirements, and development cost. Examples from various marine propulsion machinery simulations are used to illustrate the discussion.