Influence of geometric detail in component modeling

摘要

In any computational approach it is necessary to idealize the structure modeled to some extend. In much of the work completed to date using boundary element methods to model shipboard impressed current cathodic protection systems (ICCP) propellers have been idealized as solid disks. While this simplified geometry may capture the shadowing nature of the component it may not capture essential features of the near hull potential field in the vicinity of the propeller. Earlier work utilized the disk representation of propellers as a required compromise between modeling and problem size limitations. Recent advances in computing power coupled with advances in solid modeling programs have resulted in the ability to readily create complex geometries without significant concerns related to mesh size. In this work three different representations of propellers are evaluated. The hull geometry studied is that of the US Navy CVN aircraft carrier class, This hull class has 4 propellers. Two methods of representing details of propeller geometry are examined. In one case the propeller is modeled in detail including individual blades. In the second detailed approach a propeller is modeled as a solid that is shaped to simulate the complex geometry of a rotating assembly, Calculated potential fields for these two advanced geometric representations are compared with results based on the solid disk representation.