Passive Drag Reduction of Wall-Turbulent Flows

Research Project

Project/Area Number	61460076
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	Aerospace engineering
Research Institution	University of Tsukuba
Principal Investigator	TSUGE Shunichi Professor, Institute of Engineering Mechanics, University of Tsukuba, 構造工学系, 教授 (50133020)
Co-Investigator(Kenkyū-buntansha)	筒井康賢工業技術院, 機械技術研究所, 主任研究官 TSUTSUI Yasukata Head Investiqator, Mechanical Engineering Laboratory, Agency of Industrial Scien
Project Period (FY)	1986 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥5,900,000 (Direct Cost: ¥5,900,000) Fiscal Year 1987: ¥2,700,000 (Direct Cost: ¥2,700,000) Fiscal Year 1986: ¥3,200,000 (Direct Cost: ¥3,200,000)
Keywords	passive drag reduction / turbulence / レイノルズストレス / 受動制御 / トムス効果 / リブレット / 受動的表面効果 / タテ渦抑制 / トムズ効果 / 纎毛
Research Abstract	The objective of the project is to develop a devise effective for passive drag reduction of wall-turbulent flows. For this purpose two models are proposed to simulate roles of polymers which plays important roles in drag reduction known as Toms' effect. The first model is fine fibre-filament deposited on a flat plate by means of electrostatic method. The drag of the 'woolly' flat plate is measured by a specially designed apparatus using a ballancing method which edtects minute drag force as slight streamwise displacement. The measurements show, however, no drag reduction for the model because of difficulty in obtaining fibre filament fine enough to meet the purpose. The second model is then tested which consists of fishing lines placed on a flat plate and alligned in streamwise direction. For optimum configuration the drag reduction of about 7 % is observed. The height of protuberance for this case turns out to be much smaller than the riblets case.