Influence on Drag Reduction Characteristics of Jet Hole Shape on Bionic Shark Gill Surface

2014 ◽  
Author(s):  
Gang Zhao ◽  
Fang Li ◽  
Weixin Liu ◽  
Hongshi Bi ◽  
Shu Zhang
Keyword(s):  
Drag Reduction ◽  
Hole Shape ◽  
Reduction Characteristics

scholarly journals Effect of SDBS on the drag reduction characteristics of polyacrylamide in a rotating disk apparatus

2015 ◽  
Vol 4 (3) ◽  
pp. 326 ◽  
Author(s):  
Hayder A. Abdul Bari ◽  
Zainab Yousif ◽  
Zulkefli Bin Yaacob ◽  
Edward Oluwasogaakindoyo
Keyword(s):  
Drag Reduction ◽  
Rotating Disk ◽  
Reynolds Numbers ◽  
Aggregate Structure ◽  
Surfactant Micelle ◽  
Micro Particles ◽  
Transmission Electron ◽  
Speed Up ◽  
Reduction Characteristics

<p>This paper focuses on the determination of the interaction between polymer (Polyacrylamide (PAM)) and surfactant (Sodium dod benzene sulfonate (SDBS)) as a drag reducer using Rotating Disk apparatus (RDA) at various concentrations (500, 700, 1000, 1500 and 2000) ppm individually and in the combined form under turbulent conditions at different rotation speed up to 3000 rpm, as well as studying their mechanisms as a drag reducer. The results show that the maximum percent drag reduction increases to (40, 41, 43, 45 and 48)% by using the combined additives of surfactant and polymer at the above concentrations respectively, with slower degradation and display drag reduction for a larger range of Reynolds numbers. The nano and micro particles formed from the combined PAA and SDBSA was studied using cryo-transmission electron microscopy (cryo-TEM) techniques. The images show the surrounding of polymer chain to the surfactant micelle to form an aggregate structure. A hexagonal crystalline form was suggested to describe the shape of the aggregate structure.</p>

Drag Reduction of Gas-Liquid Two-Phase Flow in Steel Pipes with Different Inclination Geometry

2012 ◽  
Vol 433-440 ◽  
pp. 463-470
Author(s):  
Lei Liu ◽  
Xin Feng Guo ◽  
Qiu Yue Guo ◽  
Hui Qing Fan ◽  
Zhu Hai Zhong
Keyword(s):  
Drag Reduction ◽  
Two Phase Flow ◽  
Vertical Section ◽  
High Energy ◽  
Phase Flow ◽  
Two Phase ◽  
Steel Pipes ◽  
Horizontal Pipes ◽  
Reduction Efficiency ◽  
Reduction Characteristics

It is significant to make researches on drag reduction in two-phase transport pipeline because two-phase flow has high energy dissipation. API X 52 steel pipe with diameter of 40mm is used in this paper to simulate pipeline with different inclination geometry including horizontal, up-inclined and vertical sections. The up-inclined section has an inclination angle of eight degree. Experiments and theoretical analysis are carried out to study the drag reduction characteristics of gas-liquid two-phase flow in these three sections. The drag reducing agents used here is polyacrylamide. It is found that two-phase drag reduction varies with pipe inclination geometry. The largest drag reduction efficiency occurs in horizontal pipes and which is up to seventy percent. Drag reduction efficiency in up-inclined section is up to sixty percent. Drag reduction in vertical section is the lowest and which can be up to about thirty percent. A mechanistic drag reduction model is proposed to predict drag reduction in gas-liquid two-phase flow. The results predicted are in good agreement with the experiment data.

scholarly journals Research Progress on the Collaborative Drag Reduction Effect of Polymers and Surfactants

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 444 ◽  
Author(s):  
Yunqing Gu ◽  
Songwei Yu ◽  
Jiegang Mou ◽  
Denghao Wu ◽  
Shuihua Zheng
Keyword(s):  
Drag Reduction ◽  
Reynolds Numbers ◽  
Research Progress ◽  
Polymer Additives ◽  
Factors Affecting ◽  
Mechanism Model ◽  
Reduction Effect ◽  
Reduction Characteristics ◽  
Degradation Properties ◽  
Degradation Ability

Polymer additives and surfactants as drag reduction agents have been widely used in the field of fluid drag reduction. Polymer additives can reduce drag effectively with only a small amount, but they degrade easily. Surfactants have an anti-degradation ability. This paper categorizes the mechanism of drag reducing agents and the influencing factors of drag reduction characteristics. The factors affecting the degradation of polymer additives and the anti-degradation properties of surfactants are discussed. A mixture of polymer additive and surfactant has the characteristics of high shear resistance, a lower critical micelle concentration (CMC), and a good drag reduction effect at higher Reynolds numbers. Therefore, this paper focuses more on a drag reducing agent mixed with a polymer and a surfactant, including the mechanism model, drag reduction characteristics, and anti-degradation ability.

Rheological and drag reduction characteristics of xanthan gum solutions

1988 ◽  
Vol 27 (6) ◽  
pp. 617-627 ◽  
Author(s):  
H. -W. Bewersdorff ◽  
R. P. Singh
Keyword(s):  
Drag Reduction ◽  
Xanthan Gum ◽  
Reduction Characteristics
Sign in / Sign up

Export Citation Format

Share Document