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http://dx.doi.org/10.6110/KJACR.2015.27.7.344

Characteristics of Developing Turbulent Oscillatory Flows in a 180° Curved Duct with a Square Sectional by using a LDV  

Yun, Seok-Ju (Department of Mechanical Engineering, Graduate School of Chosun University)
Lee, Haeng-Nam (Department of Mechanical Engineering, Chosun University)
Sohn, Hyun-Chull (Department of Mechanical Engineering, Chosun University)
Publication Information
Korean Journal of Air-Conditioning and Refrigeration Engineering / v.27, no.7, 2015 , pp. 344-353 More about this Journal
Abstract
In the present study the characteristics of turbulent oscillatory flows in a square-sectional $180^{\circ}$curved duct were investigated experimentally. A series of experiments for air flow were conducted to measure axial velocity profiles, secondary flow velocity profiles and pressure distributions. The measurements were made by a Laser Doppler Velocimeter (LDV) system with a data acquisition and processing system which includes Rotating Machinery Resolve (RMR) and PHASE software. The results from the experiment are summarized as follows. (1) The maximum velocity moved toward the outer wall from the region of a bend angle of $30^{\circ}$. The velocity distribution had a positive value extended over the total phase in the region of a bend angle of $150^{\circ}$. (2) Secondary flows were generally proportional to the velocity of the main flow. The intensity of the secondary flow was about 25% as much as that in the axial direction. (3) Pressure distributions were effects of the oscillatory Dean number and respective region.
Keywords
Turbulent oscillatory flow; Velocity distribution; Square sectional curved duct; Amplitude; Secondary flow; Dimensionless angular frequence; Phase angle;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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