Effect of wavelength of fish-like undulation of a hydrofoil in a free-stream flow

作者： | Thekkethil Namshad, Mukul Shrivastava, Amit Agrawal, Atul Sharma |

作者单位： |
^{1}Indian Institute of Technology Bombay |

刊名： | Sādhanā, 2017, Vol.42 (4), pp.585-595 |

来源数据库： | Springer Nature Journal |

DOI： | 10.1007/s12046-017-0619-7 |

关键词： | Fish-like locomotion; Pitching; Undulation; Wavelength; |

英文摘要： | Fish-like undulating body was proposed as an efficient propulsion system, and various mechanisms of thrust generation in this type of propulsion are found in the literature—separately for undulating and pitching fishes/foil. The present work proposes a unified study for undulating and pitching foil, by varying wavelength \(\lambda \) (from 0.8 to 8.0) of a wave travelling backwards over the NACA0012 hydrofoil in a free-stream flow; the larger wavelength is shown to lead to the transition from the undulating motion to pitching motion. The effect of wavelength of undulation is studied numerically at a Reynolds number \(Re=4000\) , maximum amplitude of undulation \(A_{max}=0.1\) and non-dimensional frequency of undulation \(St=0.4\) , using level-set immersed-boundary-method based in-house... |

原始语种摘要： | Fish-like undulating body was proposed as an efficient propulsion system, and various mechanisms of thrust generation in this type of propulsion are found in the literature—separately for undulating and pitching fishes/foil. The present work proposes a unified study for undulating and pitching foil, by varying wavelength \(\lambda \) (from 0.8 to 8.0) of a wave travelling backwards over the NACA0012 hydrofoil in a free-stream flow; the larger wavelength is shown to lead to the transition from the undulating motion to pitching motion. The effect of wavelength of undulation is studied numerically at a Reynolds number \(Re=4000\) , maximum amplitude of undulation \(A_{max}=0.1\) and non-dimensional frequency of undulation \(St=0.4\) , using level-set immersed-boundary-method based in-house... |