Experimental investigation of drag reduction effects of polymer additives on turbulent pipe flow using ultrasound Doppler velocimetry

Date

2014-01-01

Author

Zeybek Vural, Serife
Bayram, Göknur
Uludağ, Yusuf

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

232
views

0
downloads

Drag reduction in fully developed turbulent pipe flow with 4 concentrations (200 to 500 wppm or mg/kg) of low molecular weight sodium carboxymethylcellulose (CMC) in aqueous solutions was investigated experimentally. Drag reduction was determined by pressure drop measurements. Maximum drag reduction achieved was 22% using 500 wppm CMC solution. To observe the impact of the presence of CMC on the flow, ultrasound Doppler velocimetry (UDV) was employed to monitor the instantaneous velocity distributions. Experimental measurements were used to calculate Fanning friction factor and radial distributions of the axial time-averaged velocity, velocity fluctuation (turbulent intensity), and eddy viscosity. Two impacts of increasing CMC concentration on the flow field were observed. The first effect was the decrease in the mean velocity gradient, especially near the wall, with increasing polymer amount, which in turn gave rise to a lower friction factor or pressure drop. Furthermore, smaller eddy viscosities were obtained in the flow. The second impact of polymer addition was on the velocity fluctuation or turbulent intensity variation along the radial distribution. Presence of the polymer suppressed the velocity fluctuations near the wall while the intensity in the turbulent core region became stronger than in the case of lower or no polymer addition.

Subject Keywords

General Chemistry

URI

https://hdl.handle.net/11511/47657

Journal

TURKISH JOURNAL OF CHEMISTRY

DOI

https://doi.org/10.3906/kim-1303-33

Collections

Department of Chemical Engineering, Article

Suggestions

OpenMETU
Core

Thermal catalytic hydrosilylation of conjugated dienes with triethylsilane in the presence of tricarbonyl(o-xylene)metal (metal = Cr, Mo, W) complexes Kayran, C; Rouzi, P (Walter de Gruyter GmbH, 2001-11-01) The thermal catalytic hydrosilylation of 1,3-butadiene (1), trans-2-methyl-1, 3-pentadiene (2), 2,3-dimethyl-1,3-butadiene (3), and isoprene (4), with triethylsilane were studied in the presence of M(CO)(3) (o-xylene) (M = Cr, Mo, W) complexes in polar and nonpolar solvents such as tetrahydrofuran, hexane and toluene. Mo(CO)(3) (o-xylene) was found to be the only active catalyst for the hydrosilylation of 3 with triethylsilane, which gave 1-triethylsilyl-2,3-dimethyl-2-butene (3a), as hydrosilylated product...
Phase transition of chemically synthesized FePt nanoparticles under high pressure ŞİMŞEK, TELEM; Karci, Ozgur; ÖZCAN, ŞADAN (The Scientific and Technological Research Council of Turkey, 2018-01-01) We present the results of a study related to phase transformation of chemically synthesized FePt nanoparticles under high pressure from face-centered cubic into face-centered tetragonal structure. As-synthesized nanoparticles are around 4.5 nm and show superparamagnetic behavior at 300 K. After annealing under 60 bar pressure of hydrogen at 400 degrees C for 2 h, nanoparticles exhibit strong ferromagnetic behavior with 5391 Oe coercivity. Results show that high-pressure annealing lowers the decomposition te...
ANODIC POTENTIAL HOMO ENERGY RELATIONS OF FLUORENE DERIVATIVES SEN, S; CELEBI, N; TURKER, L; Önal, Ahmet Muhtar (Wiley, 1993-09-01) Anodic oxidation peak potentials (E(p,a)) of some fluorene derivatives were measured on a Pt-degrees electrode versus Ag-degrees/Ag+ in acetonitrile-TBAFB by cyclic voltammetry. The highest occupied molecular orbital (HOMO) energies of the compounds were calculated within the Huckel molecular orbital (HMO) framework. The measured E(p,a) values were correlated to theoretical HOMO energies with a linear regression model.
Voltammetric methods of reboxetine analysis and the mechanism of its electrode reactions Altunöz Erdoğan, Deniz; Erk, Nevin; Kilic, Esma (Walter de Gruyter GmbH, 2013-05-01) Reboxetine (RBX) electrochemical redox behavior at hanging mercury drop (HMDE) and glassy carbon electrodes (GCE) was studied in various pH Britton-Robinson universal buffers using cyclic voltammetry and square-wave voltammetry. RBX was reduced at the HMDE and oxidized at the GCE with reversible adsorption controlled and irreversible diffusion controlled processes respectively. The anodic peak is due to the amine and the cathodic peak may correspond to oxygen protonation. An oxidation reaction mechanism is ...
Economic synthesis of quinaldinium fluorochromate(VI), (QnFC), and solvent-free periodic acid oxidation of alcohols catalyzed by QnFC Özdemir, Melek (The Scientific and Technological Research Council of Turkey, 2014-01-01) A 1: 1: 1 stoichiometric reaction between CrO3, aqueous HF, and quinaldine affords orange crystalline quinaldinium fluorochromate(VI) (QnFC) (C10H9NH[CrO3F]) in 99.4% isolated yield. A highly efficient, simple, chemoselective, and environmentally benign procedure for QnFC (3 mol%) catalyzed oxidation of primary and secondary alcohols to aldehydes and ketones using 1.1 equiv of H5IO6 under solvent-free conditions is described.

Citation Formats

S. Zeybek Vural, G. Bayram, and Y. Uludağ, “Experimental investigation of drag reduction effects of polymer additives on turbulent pipe flow using ultrasound Doppler velocimetry,” TURKISH JOURNAL OF CHEMISTRY, pp. 142–151, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47657.