Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Numerical Investigations on Unsteady Cavitation of a High-Skew CP Propeller with a Hole
Jianqiang Wang1,2,3 ,Min Zhou1
1Marine Design & Research Institute of China,
2Shanghai Jiaotong University,
3Laboratory of Science and Technology on Waterjet propulsion.

Shanghai, China.

cavitation characteristics of the punches in different blade areas areinvestigated by numerical simulations.

ABSTRACTThis paper presents results of the numerical and experimental
investigations of the cavitation characteristics of a high-skew CP
propeller. To improve the cavitation performance, the blade with holesof different sizes and positions has been designed and numericallyresearched. Based on cavity positions, a hole is drilled at the cavity area
to improve the local pressure distribution and cavitating behaviour. The
hole influences the hydrodynamic performance slightly. The holes withspecific size and position near the leading edge alters the position andpattern of the sheet cavity. Similarly, a hole at the root can effectively
decrease the root cavity.

There's been little research on slotting or holing in the propeller blade.
However, ongoing investigations have been conducted on the slots inairfoils and turbo machinery applications.
The first detailed research on the slotted airfoil was performed byWeick(1933). In his study, various combinations of slot area areinvestigated to identify optimized configurations. M. Ramzi and G.
AbdErrahmane (2013) have analyzed the effects of location, width andslope of slots through an extensive 2D-numerical study. The best
configuration was also identified. The numerical results show that amaximum of almost 28% reduction in loss coefficient had been reachedand the flow turning was increased with approximately 50.

KEY WORDS: CPP; cavitation; numerical simulation; hole.
INTRODUCTION
The body of the paper begins with the Introduction. In the Introduction,state the purpose of the paper, or author’s aim, so that the reader will
have a clear concept of the objective(s). Following the Introduction,text should be organized into logical parts or sections that describe theproblem, the means of solution, technical data or substantiation andother information necessary to qualify properly the results presented
and conclusions drawn. Acknowledgments (where applicable),
References, and Appendices (where applicable) follow the Conclusions.
Controllable pitch propellers (CPP) can meet the requirement ofmultiple conditions of the surface ship and improve the propulsion
performance and ship maneuverability under different working
conditions. Compared to conventional propeller, the hub dimeter CP
propellers is much bigger, because of the complicated blade adjustment
mechanism. With regard to the heavy-loaded CP propeller, sheet cavity
and hub root cavity of the blade back are often observed. To reduce thecavity pattern area, much work has been down, for example, pitch
distribution, high skew adjustment and so on. In this paper, a special
method is introduced to improve the CPP cavitation performance, thatis holing the propeller blade in the cavity area. The numerical andexperimental investigations of the cavitation characteristics of a highskew CP propeller in the design condition are presented. Then theFor centrifugal fans with slotted blades some researches have been
conducted with numerical simulation by Yukun Lv et al. (2012) andRui Ronga et al. (2015). The research shows that slotted technique on
centrifugal fan blade is useful to improve the characteristics of bladesurface flow field, resulting in significant energy saving. Liu Fei et al.
(2007) conducted researches of aerodynamic performance on the large
turning angles cascade with chordwise slots. Their simulations showthat reasonable chordwise slots can improve the pressure distribution
along cascade surface by controlling the boundary layer development
near suction surface. Huang Dongtao et al. (2009) improve thecentrifugal fan performance under the variable conditions bycontrolling the length of slotted blade.
For wind turbine with slotted blades, Mohamed Ibrahim et al. (2015)
conducted the wind tunnel experiment and numerical simulations on
slotted blade design. Muraleekrishnan Menon et al. (2016) applied
trailing-edge slotted-flap concept into existing blade designs.
Kutty, Hairuniza Ahmed, Parvathy Rajendran, and Akshay Mule (2017)
discussed CFD method to predict UAV propeller performance for small
scale low Reynolds number propeller with new slotted blade designs. The
performance of slotted propeller blade is influence by the position of the3320