スギモト タケシ   Sugimoto Takeshi
  杉本 剛
   所属   神奈川大学  工学部 情報システム創成学科
    神奈川大学大学院  工学研究科 工学専攻(情報システム創成領域)
   職種   教授
言語種別 日本語
発行・発表の年月 2009/02
形態種別 学術雑誌
査読 査読あり
標題 Revisiting the energetics of porpoising in penguins
執筆形態 単著
掲載誌名 Theor. & Appl. Mech. Jpn
巻・号・頁 57,331-338頁
概要 Some insist penguins porpoise to save the energy at high speeds. Some believe penguins porpoise to breathe without losing their speed. Others think penguins porpoise to watch predators in the air and on the shore. The present proposal is introduction of equations of motion: a penguin is treated as a particle; the conventional aerodynamics and hydrodynamics is used; added mass is incorporated to capture the effect due to splash; constant power is assumed. As the penguin dashes out of the water, it sprays water around: the added mass in the water is assumed as an impact, whilst the added mass in the air is neglected; no wave resistance is incorporated, because penguins are quite streamlined. Parameters are determined so as to explain the existing field data. The results show the following facts: to porpoise almost half of the power is used to the vertical motion; constant speed swimming consumes half the power of porpoising at the same average speed.