English  |  正體中文  |  简体中文  |  Items with full text/Total items : 28611/40649
Visitors : 636292      Online Users : 70
RC Version 4.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Adv. Search

Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/24429

Title: 3D Measurements of the Mean Velocity and Turbulence Structure Within the Near Wake of a Rotor Blade
Authors: Francesco Soranna;Yi-Chih Chow;Oguz Uzol;Joseph Katz
Contributors: NTOU:Department of Systems Engineering and Naval Architecture
Keywords: Measurement;Turbulence;Wakes;Rotors;Blades
Date: 2005
Issue Date: 2011-10-20T08:12:17Z
Publisher: ASME 2005 Fluids Engineering Division Summer Meeting
Abstract: Abstract:Stereoscopic PIV measurements examine the flow structure and turbulence within a rotor near wake located in a non-uniform field generated by a row of Inlet Guide Vanes (IGVs). The experiments are performed in a refractive index matched facility that provides unobstructed view of the entire flow field. The data are acquired at 10 closely spaced radial planes located near mid-span, which enable measurements of all the components of the mean strain rate and Reynolds stress tensors. Chopping and variations of advection speed of the upstream IGV wakes, as they pass along the rotor blade, create a non-uniform flow that shears the rotor wake. However, the phase averaged flow at mid span remains almost two-dimensional. Due to the overwhelming effects of the non-uniform strain field, the presently observed trends of the Reynolds stresses within the sheared wake differ from those measured in previous studies of curved wakes. The axial velocity fluctuations increase along the suction/outer side of the wake, while the other components decay. On the pressure/inner part of the wake the circumferential velocity fluctuations are higher. The shear stress has a complex distribution, but is also higher on the suction side. To explain these trends the stresses and production rates are examined in coordinate systems aligned with the principal strain directions. As expected, the production is high along the compressive directions and low, even negative, in the extensive directions. Accordingly, the compressed normal stress component increases along the wake, while the extended component decays. The in-plane shear stress component and its associated production remain very high in the principal coordinate system of the strain. Projecting the stresses back to the laboratory coordinate system explains the observed inhomogeneous anisotropic distribution of Reynolds stresses within the kinked wake.
Relation: FEDSM2005-77315, pp.1289-1307
URI: http://ntour.ntou.edu.tw/handle/987654321/24429
Appears in Collections:[系統工程暨造船學系] 演講及研討會

Files in This Item:

There are no files associated with this item.

All items in NTOUR are protected by copyright, with all rights reserved.


著作權政策宣告: 本網站之內容為國立臺灣海洋大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用,請合理使用本網站之內容,以尊重著作權人之權益。
網站維護: 海大圖資處 圖書系統組
DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback