Next Article in Journal
Evaluation of Water Content in an Active Layer Using Penetration-Type Time Domain Reflectometry
Previous Article in Journal
Ambient Pressure Laser Desorption—Chemical Ionization Mass Spectrometry for Fast and Reliable Detection of Explosives, Drugs, and Their Precursors
Article Menu
Issue 6 (June) cover image

Export Article

Open AccessArticle
Appl. Sci. 2018, 8(6), 934; https://doi.org/10.3390/app8060934

Effects of Regular Waves on Propulsion Performance of Flexible Flapping Foil

1
College of Engineering, Ocean University of China, Qingdao 266100, China
2
Beijing Aerospace Unmanned Vehicles System Engineering Research Institute, Beijing 100094, China
3
School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
4
Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone, Qingdao 266033, China
5
Science and Technology on Underwater Vehicle Laboratory, Harbin Engineering University, Harbin 150001, China
*
Authors to whom correspondence should be addressed.
Received: 26 April 2018 / Revised: 28 May 2018 / Accepted: 1 June 2018 / Published: 5 June 2018
View Full-Text   |   Download PDF [2488 KB, uploaded 5 June 2018]   |  

Abstract

The objective of the present study is to analyze the effects of waves on the propulsive performance and flow field evolution of flexible flapping foil, and then offer a way to take advantage of wave energy. The effects of regular waves on the propulsive performance of a two-dimensional flexible flapping foil, which imitated the motion and deformation process of a fish caudal fin, were numerically studied. Based on computational fluid dynamic theory, the commercial software Fluent was used to solve the Reynolds-averaged Navier–Stokes equations in the computational domain. Several numerical models were employed in the simulations, which included user-defined function (UDF), numerical wave tank (NWT), dynamic mesh, volume of fluid (VOF), post-processing, and analysis of the wake field. The numerical tank was also deep enough, such that the tank bottom had no influence on the surface wave profile. First, the numerical method was validated by comparing it with experimental results of rigid foil, flapping under waves. The effects of three key wave parameters on the propulsive performance of flexible and rigid foils were then investigated; the results show that higher performance can only be obtained when the motion frequency of the foil was equal to its encounter frequency with the wave. With this precondition, foils were able to generate higher thrust force at larger wave amplitudes or smaller wavelengths. Similarly, the percentage of wave energy recovery by foils was higher at smaller wave amplitudes or wavelengths. From a perspective of wake field evolution, increasing foil velocity (relative to water particles of surrounding waves), could improve its propulsive performance. In addition, flexible deformation of foil was beneficial in not only enhancing vortex intensity but also reducing the dissipation of vortices’ energy in the flow field. Therefore, flexible foils were able obtain a better propulsive performance and higher wave energy recovery ability. View Full-Text
Keywords: flexible flapping foil; propulsion performance; computational fluid dynamics; regular wave; wake field flexible flapping foil; propulsion performance; computational fluid dynamics; regular wave; wake field
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Liu, P.; Liu, Y.; Huang, S.; Zhao, J.; Su, Y. Effects of Regular Waves on Propulsion Performance of Flexible Flapping Foil. Appl. Sci. 2018, 8, 934.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Appl. Sci. EISSN 2076-3417 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top