Document Type : Original Article
Authors
1
Professor, Department of Mechanical Power Engineering, Menoufia University, Shebin El-Kom, Egypt.
2
Associate Professor, Department of Mechanical Power Engineering, Menoufia University, Shebin El-Kom, Egypt.
3
Lecturer, Department of Mechanical Power Engineering, Menoufia University, Shebin El-Kom, Egypt.
4
Graduate student, Department of Mechanical Power Engineering, Menoufia University, Shebin El-Kom, Egypt.
Abstract
Experimental studies of the total loss coefficient and pressure distribution, for turbulent Newtonian and drag reduction flows in bends and tees are presented. Dilute solutions of polyethylene glycol in water were used as the drag reducing fluids. Drag reduction was deduced from plots of experimental pipe flow data, on Prandtl-Karman coordinates. Two main test sections were studied. The first test section was a commercial 90° bend,while the second was a commercial tee section. The later test section was studied in different situations such as a distributer , a collector, a by-pass and a bend. Estimation of the total loss coefficient required an evaluation of a kinetic energy correction factor. Based on previous theoretical and experimental verifica-tions, this factor was determined from the friction factor Reynolds number pipe flow data, for the different flowing fluids. Thus, a reasonally accurate evaluation of the total loss coeffi-cient could be obtained. The results showed that drag reducing polymer additives cause a reduction in the total loss coefficient for all flow situations studied. Pressure distributions along the different sections were presented both with physical inter-pretations and discussion of some flow separation aspects. The results showed that the pressure distributions along the studied sections had the same trend for both Newtonian and drag reduction flows.
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