2012

Effect of Pipe Roughness on Pressure Losses of Newtonian Fluids in Concentric Annulus

Pressure loss is one of the important parameters in hydraulic engineering. Especially for the large Reynolds Number, relative roughness has a significant effect on pressure losses in annulus.In this study, water flowing through rough and smooth concentric annulus for turbulent flow is modeled using Computational Fluid Dynamics (CFD). CFD software based on the finite element method predictions of pressure losses are compared with experimental data obtained from the literature. The model predicts measured frictional pressure gradient with an error less than ±15% in all cases. Furthermore, pipe roughness influences on frictional pressure losses of water are also examined for various pipe roughness values, inner and outer diameters and Reynolds Number. The analysis results revealed that as the diameter ratio increases, the influence of roughness on pressure gradient increases.

PDF

___

[1] Blasius, H. Das Ähnlichkeitsgesetz bei Reibungsvorgängen in Flüssigkeiten. Forsch. Arb. Ing.,1913; 134.
[2] Nikuradse, J. Laws of Turbulent Flow in Smooth Pipes. NASA, Report No. TTF-10, 1932.
[3] Prandtl, L. Neuere ergebnisse der turbulenzforschung. VDI Z. (1857-1968), 1933; 77, 105-114.
[4] Colebrook, C.F. Turbulent Flow in Pipes With Particular Reference to the Transition Region Between the Smooth and the Rough Pipe Laws, J. Inst. Civ. Eng. 1939; 11, 133-156.
[5] McKeon, B. J., Zagarola, M. V., and Smits, A. J. A New Friction Factor Relationship for Fully Developed Pipe Flow. J. Fluid Mech. 2005; 538, 429-443.
[6] Moody, L. F. An Approximate Formula for Pipe Friction Factors. Trans. ASME. 1947; 69, 1005-1006.
[7] Haaland, S. E. Simple and Explicit Formulas for the Skin Friction in Turbulent Pipe Flow. ASME J. Fluids Eng. 1983; 105, 89-90.
[8] Manadilli, G. Replace implicit equations with signomial functions. Chem. Eng. 1997; 104 (8), 129-130.
[9] Chen, N. H. An Explicit Equation for Friction Factor in Pipe. Ind.Eng. Chem. Fundam. 1979; 18 (3), 296-297.
[10] Avci, A., Karagoz, I. A novel explicit equation for friction factor in smooth and rough pipes. J. Fluid. Eng. ASME. 2009; 131 (6), 1-4 061203.
[11] Kelessidis V.C., Dalamarinis P., Maglione R. Experimental Study and Predictions of Pressure Losses of Fluids Modeled As Herschel-Bulkley in Concentric and Eccentric Annuli in Laminar, Transitional and Turbulent Flows. Journal of Petrolem Science and Engineering. 2011; 77, 305-312.
[12] ANSYS Version 12.0, 2009. ANSYS Workbench CFD. ANSYS Inc. Southpointe 275 Technology Drive Canonsburg, PA 15317, USA.
[13] Fang, X., Xu Y., and Zhou Z. New Correlations of single-phase friction factor for turbulent pipe flow and evaulation of existing single-phase friction factor correlations. Nuclear Engineering and Design. 2011; 241, 897-902.

Celal Bayar Üniversitesi Fen Bilimleri Dergisi-Cover

ISSN: 1305-130X
Başlangıç: 2005
Yayıncı: Manisa Celal Bayar Üniversitesi Fen Bilimleri Enstitüsü

Arşiv