Propulsive performance of a newly conceptual design of flapping foil with fixed gurney plate- A numerical study. (1st November 2021)

• Record Type: Journal Article
• Authors: Li, Yongcheng; Zhang, Nan; Pan, Ziying
• Is Part Of: Ocean engineering. Volume 239(2021)
• Publication Date: 2021-11-01
• Subjects: Flapping foil -- Propulsive performance -- Fixed gurney plate -- Numerical simulation; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2021.109800
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: In order to improve the propulsive performance of flapping foil, a new conceptual design of flapping foil device is proposed in current study by adding a pair of fixed gurney plates to the trailing end of flapping foil. The two-dimensional transient numerical study has been carried out to analyse the propulsive performance of current flapping foil at a Reynolds number of 1.0 × 10 6 . In addition, the effect of non-dimensional flapping frequency ( S t number), the gurney plate length as well as the gurney plate position along the chord length direction of the foil has also been conducted. The numerical results reveal that the current flapping foil with fixed gurney plate exhibits better propulsive performance than the conventional one by increasing the thrust force within the whole motion period. Similar with the conventional one, the S t number is also a dominant parameter in evaluating the propulsive efficiency and the optimum value leading to highest propulsive efficiency varies around 0.3. The simulation results indicate that the geometric parameter of gurney plate length does not always play a positive role in improving propulsive efficiency and there exists optimal gurney plate length corresponding to highest propulsive efficiency. The numerical results also demonstrates that the more closer the gurney plate is to the trailing edge of flapping foil, the better the propulsive performance of flapping foil will be. Conclusions acquired in this study may provide some guidance for the design of bionic propulsion device or vehicle. Highlights: A novel conceptual design of flapping foil is proposed. An optimum value of St number is reported for acquiring highest efficiency. The flow mechanism has been found to be responsible for good propulsive performance of current flapping foil.