Dynamics and hydrodynamic efficiency of diving beetle while swimming

Debo Qi; Chengchun Zhang; Zhengyang Wu; Chun Shen; Yongli Yue; Luquan Ren; Liang Yang

doi:10.1016/j.heliyon.2023.e14200

Dynamics and hydrodynamic efficiency of diving beetle while swimming

Heliyon. 2023 Mar 1;9(3):e14200. doi: 10.1016/j.heliyon.2023.e14200. eCollection 2023 Mar.

Authors

Debo Qi¹, Chengchun Zhang^{1

2

3}, Zhengyang Wu^{1

2}, Chun Shen^{1

3}, Yongli Yue¹, Luquan Ren¹, Liang Yang⁴

Affiliations

¹ Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun, 130025, China.
² Weihai Institute for Bionics, Jilin University, Weihai, 264402, China.
³ State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun, 130025, China.
⁴ Lecturer in Marine Renewable Energy System, Cranfield University, Cranfield, MK43 0AL, UK.

Abstract

Diving beetle, an excellent biological prototype for bionic underwater vehicles, can achieve forward swimming, backward swimming, and flexible cornering by swinging its two powerful hind legs. An in-depth study of the propulsion performance of them will contribute to the micro underwater vehicles. In this paper, the kinematic and dynamic parameters, and the hydrodynamic efficiency of the diving beetle are studied by analysis of swimming videos using Motion Capture Technology, combined with CFD simulations. The results show that the hind legs of diving beetle can achieve high propulsion force and low return resistance during one propulsion cycle at both forward and backward swimming modes. The propulsion efficiencies of forward and backward swimming are 0.47 and 0.30, respectively. Although the efficiency of backward swimming is lower, the diving beetle can reach a higher speed in a short time at this mode, which can help it avoid natural enemies. At backward swimming mode, there is a long period of passive swing of hind legs, larger drag exists at higher speed during the recovery stroke, which reduces the propulsion efficiency to a certain extent. Reasonable planning of the swing speed of the hind legs during the power stroke and the recovery stroke can obtain the highest propulsion efficiency of this propulsion method. This work will be useful for the development of a bionic propulsion system of micro underwater vehicle.

Keywords: Added mass force; Diving beetle; Drag force; Hydrodynamic efficiency; Propulsion force.