TURBULENCE TRANSPORT OF SURFACTANT SOLUTION FLOW DURING DRAG REDUCTION DEGENERATION

• Published in: Journal of hydrodynamics. Series B Vol. 24; no. 4; pp. 479 - 487
• Main Authors: GU, Wei-guo, WANG, De-zhong
• Format: Journal Article
• Language: English
• Published: Singapore Elsevier Ltd 01.09.2012; Springer Singapore; School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
• Subjects: CTAC; Degeneration; Drag reduction; drag reduction degeneration; Engineering; Engineering Fluid Dynamics; Fluid dynamics; Fluid flow; Hydrology/Water Resources; Numerical and Computational Physics; quadrant analysis; Quadrants; Simulation; surfactant; Surfactants; Turbulence; turbulence transport; Turbulent flow; 十六烷基三甲基氯化铵; 变性过程; 液流; 湍流减阻; 粒子图像测速; 表面活性剂; 运输过程; turbulence transport; drag reduction degeneration; surfactant; quadrant analysis
• ISSN: 1001-6058; 1878-0342
• DOI: 10.1016/S1001-6058(11)60269-2

Turbulence transport of surfactant solution flow during drag reduction degeneration is investigated experimentally in a two-dimensional channel. Particle Image Velocimetry （PIV） system is used to take two-dimensional velocity frames in the stream- wise and wall-normal plane. The additive of surfactant is cetyltrimethyl ammonium chloride （CTAC） with the mass concentration of 25 ppm. Drag reduction degeneration happens in the CTAC solution flow, exhibiting the maximal drag reduction at Re = 25 000 and losing drag reduction completely at Re - 40 000. The velocity frames are statistically analyzed in four quadrants which are divi- ded by the u - axis and v - axis. It is found that the phenomenon of ＂Zero Reynolds shear stress＂ is caused by the decrease of wall- normal fluctuations and its symmetrical distribution in quadrants. The increase of Reynolds number leads to the enhancement of tur- bulence burst phenomenon. During the drag reduction degeneration, the CTAC solution flow contains both high turbulence intensity and drag reduction states.