Improved hydrodynamic performance of a collective and cyclic pitch propeller by numerical evaluation of the blade design
Dubois, A and Leong, ZQ and Nguyen, HD and Binns, JR, Improved hydrodynamic performance of a collective and cyclic pitch propeller by numerical evaluation of the blade design, Ocean Engineering: An International Journal of Research and Development, 220 Article 108404. ISSN 0029-8018 (2021) [Refereed Article]
The collective and cyclic pitch propeller (CCPP) is a novel concept designed to propel and manoeuvre autonomous underwater vehicles (AUVs). Collective pitch control governs the generated thrust, while through cyclic pitch control a manoeuvring force/side-force is generated. Recent work concluded that new solutions are needed to achieve large side-forces without compromising the observed phase shift. In this paper, increasing the blade surface area is rationalised as the most effective pathway to achieve improved CCPP performance. A three-dimensional numerical RANS-based periodic numerical model was used to evaluate three alternative blade designs. Clear performance improvements were realised by the new blade design, manifested in the ability to generate larger side-forces, both absolute and relative based on the actual surface area, at much smaller phase shifts. A performance improvement relation was established, stating that optimal improvement is realised by increasing both the blade's surface area and aspect ratio. At higher aspect ratios, the side-force is produced in a more efficient manner, both from a general force behaviour and a side-force force generation perspective. Finally, an important note was made regarding the future introduction of blade twist in order to address an observed effect on the ‘neutral’ pitch angle.
collective and cyclic pitch propeller, CFD, blade design, propulsion, manoeuvring