The Experiment and Numerical Calculation of Propeller Performance with Surface Roughness Effects

抄録

As well known, propeller and hull of ship are fouled and their surface are roughened due to various causes such as adhesion of sea-lives, painting degradation, cavitation erosion etc. The surface roughness induces so not only the crease of hull frictional resistance, but also the deterioration of propeller performance gets worse undesirably.
This paper investigates the influence of surface roughness on propeller performance. A series of experiments are carried out in order to investigate how the propeller performance is affected by its surface roughness using a model propeller of which blade surface has been roughened artificially.
A numerical estimation method of roughness effects on propeller performance is developed by the use of a model that the propeller blade section is deformed apparently by the boundary layer displacement thickness. The validity of this method is confirmed by the comparison of experimental results. Further this method is applied for estimating the fouling effect of an actual propeller of the training ship “FUKAE-MARU” of Kobe University of Mercantile Marine.