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.
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http://dx.doi.org/10.3390/ma13020444 | DOI Listing |
ACS Appl Mater Interfaces
March 2025
Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, P. R. China.
Slippery liquid-infused porous surfaces (SLIPSs), a class of functional bioinspired surface, have earned a position at the forefront of many areas such as anticorrosion, anti-icing, antifogging, antibacterial, anticontaminant, microflow control, and drag reduction. However, the fast self-replenishing ability of SLIPS remains extremely challenging due to limited lubricant storage capacity or microstructure impeding fluid flow. Herein, a superhydrophobic surface was prepared by spraying the sepiolite/zeolitic imidazolate framework-8 hybrid material with a layered three-dimensional (3D) fibrous porous network structure on the magnesium (Mg) alloy surface.
View Article and Find Full Text PDFJ R Soc Interface
March 2025
Hefei University of Technology, Hefei, Anhui, China.
The lateral moving resistance of a liquid droplet on a solid surface generally increases with velocity and is dominated by the non-viscous wetting line friction. Many superhydrophobic man-made and biological surfaces have minimal, nevertheless speed-sensitive, water droplet friction, limiting their potential to reduce drag at high speeds in natural situations. Using an surface force apparatus, we demonstrated low and remarkably speed-insensitive (over 300-fold) water bridge sliding friction on a goose feather vane.
View Article and Find Full Text PDFPLoS One
February 2025
College of Mechanical and Electrical Engineering, Qingdao Agricultural University, Qingdao, China.
Aiming at the problems of high working resistance and high energy consumption in potato crop harvesting in sticky soil, this paper designs a potato bionic drag-reducing digging shovel based on the streamline shape of catfish head. Based on the theoretical analysis and discrete element method (DEM) simulation, the main factors affecting the digging resistance are the angle of entry, forward speed and vibration frequency, and the digging resistance increases with the increase of forward speed, and decreases with the increase of vibration frequency. Through the orthogonal test in the field, the optimal working parameters of the drag reduction performance are determined with the digging resistance as the test index, and the comparative test of the different shovel shapes is carried out with this parameter.
View Article and Find Full Text PDFMethods Protoc
February 2025
Department of Swimming, Wroclaw University of Sport and Health Sciences, 51-612 Wroclaw, Poland.
This study explores the application of the Least Squares Method to analyze and model the kinematic parameters in monofin swimming, focusing on stroke rate, stroke length, and the amplitudes of joint displacements at the hip, knee, and ankle. The primary aim is to evaluate whether this method provides an objective and diagnostic tool for assessing monofin swimming techniques. Three elite monofin swimmers were evaluated under a progressive fatigue test.
View Article and Find Full Text PDFLangmuir
March 2025
School of Marine Science and Technology, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
The liquid-liquid interface (LLI), which is the key to cause flow slippage and thus promote drag reduction of liquid-infused surfaces (LISs), does suffer from the action of flow shear. In the current study, the transverse many-body dissipative dynamics simulation method is applied to explore the shear evolution of LLI and the corresponding slippage over a periodically grooved LIS. Results show that a relatively small shear rate only induces a slight deformation of LLI and the corresponding effective slippage is dependent on the shear rate.
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