Propulsive capability of manta rays' flapping pectoral fins has inspired many to incorporate these fins as propulsive mechanisms for autonomous underwater vehicles. In particular, geometrical factors such as sweep angle have been postulated as being influential to these fins' propulsive capability, specifically their thrust generation. Although effects of sweep angle on static/flapping wings of aircrafts/drones have been widely studied, little has been done for underwater conditions. Furthermore, the findings from air studies may not be relatable to the underwater studies on pectoral fins because of the different Reynolds number (compared to the flapping wings) and force generation mechanism (compared to the static wings). This paper aims to establish a relationship between the sweep angle and thrust generation. An experiment was conducted to measure the thrust generated by 40 fins in a water channel under freestream and still water conditions for chord Reynolds number between 2.2 × 104 and 8.2 × 104. The fins were of five different sweep angles (0 deg, 10 deg, 20 deg, 30 deg, and 40 deg) that were incorporated into eight base designs of different flexibility characteristics. The results showed that the sweep angle (within the range considered) may have no significant influence on these fins' thrust generation, implying no significant effects on thrust under uniform flow condition and on the maximum possible thrust under still water. Overall, it can be concluded that sweep angle may not be a determinant of thrust generation for flapping pectoral fins. This knowledge can ease the decision-making process of design of robots propeled by these fins.
A Relationship Between Sweep Angle of Flapping Pectoral Fins and Thrust Generation
Waurn Ponds 3216, VIC, Australia;
National University of Singapore,
Contributed by the Mechanisms and Robotics Committee of ASME for publication in the JOURNAL OF MECHANISMS AND ROBOTICS. Manuscript received April 25, 2018; final manuscript received October 4, 2018; published online December 10, 2018. Assoc. Editor: Robert J. Wood.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Arastehfar, S., Chew, C., Jalalian, A., Gunawan, G., and Yeo, K. S. (December 10, 2018). "A Relationship Between Sweep Angle of Flapping Pectoral Fins and Thrust Generation." ASME. J. Mechanisms Robotics. February 2019; 11(1): 011014. https://doi.org/10.1115/1.4041697
Download citation file:
- Ris (Zotero)
- Reference Manager