Rheological Modelling of Turbid River Water

Sumia Salih Mahmoud, Isam Mohammed Abdel-Magid, Sarra Ahmed Mohamed Saad


This study focused on impact of sediment laden water of the Nile - especially during flood season - on viscosity, rheological properties and flow characteristics of water within water network and piping systems. Laboratory experiments, performed at the National Research Centre Laboratories at Khartoum, were conducted on water samples collected from the Blue Nile and for carefully prepared synthetic slurries that resembled turbid flood water during the period 2009 to 2011. Experiments showed that water viscosity increased due to an increase in amount of sediment load and concentration in tested water samples. Moreover, laboratory investigations revealed that viscosity of water laden with sediment increased whenever sediment remained within the water for a period of time. Experimental results on rheological

characteristics of samples showed that slurries and water laden sediments have flow properties of Non-Newtonian fluids with thixotropic characteristics and flow behavior. This may be attributed to the nature of suspended loads, characteristics of colloidal solids and particulate matter constituting the sediments. Such behavior will have its critical impact on pumping of such waters, their transportation and conveyance within networks and piping lines. SPSS program was used for analyzing laboratory data to deduce an equation that would suitably reflect and explain the relationship between water viscosity and sediment concentration. Likewise, the study achieved same results as laboratory investigations and findings. Modeling through COMSOL multiphysics program. enabled developing a relationship between viscosities, pressures and flow velocities within water network systems. Flow pattern, streamlines, changes in velocity, variations in velocity gradients, pressures, currents and pattern of flow under different structural, loading and hydraulic conditions were significant. Results and findings showed the decrease of velocity of flow with an increase in sediment concentration and load. The integrated holistic modelling tested in this research work reflected the influence of rheological aspects of quality factors (such as viscosity), engineering design parameters (such as hydraulic loading conditions), geometry and shape (such as size and area of conduits). Such modelling approach will have its significant impacts on decision making, design concepts and economical costs and benefits relationships when dealing with transportation and conveyance of turbid sediment laden waters.


rheological properties; Nile water; modelling

Full Text:



Mahmoud, S. S., Interactive Rheological Modeling of Turbid Water. Ph.D. Thesis. Council of Biological, New Technologies & Environmental Studies at Sudan Academy for Sciences, 2011.

University of California and the Mediterranean, The Nile River Report, URL: http://www.Cal-Cat.Com/Nileriver_04.Htm, Nov. 2008. 3. Sochi, T., Non-Newtonian flow in porous media, Polymer 51, 2010, pp. 5007-5023, www.elsevier.com/locate/polymer. 4. Mendes, P. R. S., Marchesini, F. H. and Varges, P. R., Gravity-driven azimuthal flow of a layer of thixotropic fluid on the inner surface of a horizontal tube, Journal of Non-Newtonian Fluid Mechanics 166, 2011, pp. 1004–1011, http://www.elsevier.com/locate/jnnfm. 5. Evankoa, C. R., Delisioa, R. F. 1, Dzombak, D. A. and Novak, J. W., Influence of aqueous solution chemistry on the surface charge, viscosity and stability of concentrated alumina dispersions in water, Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 125, Issues 2-3, 2 June 1997, pp. 95-107, http://www.sciencedirect.com/science/article/pii/S0927775796038745 6. Sherwood, J. D., Transient flow of viscoelastic, thixotropic fluid in a vane rheometer or infinite slot, J. Non-Newtonian Fluid Mech. 154, 2008, pp. 109–119, www.elsevier.com/locate/jnnfm. 7. Scott, B., Thickeners rheology guide, published online by Scott Bader Co., URL: http://www.scottbader.com/downloads/UK_PDF_Datasheet_Files/Rheology %20Brochure%20.pdf, Apr. 2008. 8. Mhaisalkar1, V.A. Paramasivam, R. and, Bhole, A.G., Optimizing physical parameters of rapid mix design for coagulation-flocculation of turbid waters, Water Research, Volume 25, Issue 1, January 1991, pp. 43-52, http://www.sciencedirect.com/science/article/pii/004313549190097A 9. Jenkinson, I. R. and Sun, J., Rheological properties of natural waters with regard to plankton thin layers. A short review, Journal of Marine Systems, Volume 83, Issues 3-4, November 2010, Pages 287-297, http://www.sciencedirect.com/science/article/pii/S0924796310000692. 10. Muyibi, S. A. and Evison, L. M., Optimizing physical parameters affecting coagulation of turbid water with Morninga oleifera seeds, Water Research, Volume 29, Issue 12, December 1995, pp. 2689-2695, http://www.sciencedirect.com/science/article/pii/0043135495001336 11. Perona, P., Rheology and non-Newtonian fluid mechanics with applications, Institute of Environmental Engineering, Switzerland, available online via URL: http://www.luiw.ethz.ch/FC_Labor/Projekte/Wasserwirtschaft/ Rheology_and_non-Newtonian_fluid.pdf, Feb. 2009. 12. Ferraris, C. F., Measurement of the rheological properties of high performance concrete, Journal of Research of The National Institute of Standards and Technology, Vol. 104-5, p.p. 461-478, 1999, Jan.2009. 13. Abdel-Magid, I. M., Hassan, A. H., Alloba, M. A. A., The influence of local filter Aids on Sewage sludges dewatering practice, The Bulletin of High Institute of Public Health, Alexandria University, Egypt, Vol. 25(1), pp. 145-153, 1995 14. Kurlat, A. D. H., Bisceglia, M., Ginzberg, B., Baikauskas, L. and Romano, S. D. , Induced electric birefringence and viscosity studies in microemulsions, Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 106, Issue 1, 10 January 1996, Pages 11-21.

Beris A. N., Stiakakis E., and Vlassopoulos, D. A thermodynamically consistent model for the thixotropic behavior of concentrated star polymer suspensions, J. Non-Newtonian Fluid Mech. 152, 2008, pp. 76–85, 16. Livescu S., Roy, R. V. and Schwartz, L. W., Leveling of thixotropic liquids, J. Non-Newtonian Fluid Mech. 166, 2011, pp. 395–403, www.elsevier.com/locate/jnnfm. 17. Lee C. H. Moturi, V. and Lee, Y., Thixotropic property in pharmaceutical formulations, Journal of Controlled Release 136, 2009, pp. 88–98, www.elsevier.com/locate/jconrel. 18. Abdel-Rahem, R., Gradzielski and Hoffmann, M. H., A novel viscoelastic system from a cationic surfactant and a hydrophobic counter ion, Journal of Colloid and Interface Science, Volume 288, Issue 2, 15 August 2005, Pages 570-582, http://www.sciencedirect.com/science/article/pii/S0021979705003000. 19. Andree, S., Wilms, H. and Helfmann, J., Feasibility of dermal water content determination by spatially resolved reflectance, Medical Laser Application, Volume 26, Issue 3, August 2011, Pages 109-118 20. Poole, R. J. and Escudier, M. P., Turbulent flow of non-Newtonian liquids over a backward-facing step: Part I. A thixotropic and shear-thinning liquid, Journal of Non-Newtonian Fluid Mechanics, Volume 109, Issues 2-3, 1 February 2003, Pages 177-191 21. Billingham, J. and Ferguson J.W.J., Laminar, unidirectional flow of a thixotropic fluid in a circular pipe, Journal of Non-Newtonian Fluid Mechanics, Volume 47, June 1993, Pages 21-55. 22. Negrão, C. O.R., Franco, A. T. and Rocha L. L.V., A weakly compressible flow model for the restart of thixotropic drilling fluids, Journal of Non-Newtonian Fluid Mechanics, 166, 2011, pp.1369–1381, http://www.elsevier.com/locate/jnnfm. 23. COMSOL Group, COMSOL Multiphysics User’s Guide, Matlab Interface Guide, Version 3.5, COMSOL AB., 2008. 24. Goranovid, G. and Bruus, H., Simulations In Microfluidics, Microsystem Engineering of Lab-on-a-Chip Devices - Chapter 5, VCH-Wiley, Weinheim, 2003. 25. Bruus, H., Theoretical Microfluidics, Oxford University Press, Oxford, 2007. 26. IBM Corporation, IBM SPSS Statistics, Version 19.0.0, USA, 2010. 27. Tasneem Isam Abdel-Magid, Mohammed Hashim Siddig, and Ali Mohammed Alsiori., Simulation of blood circulatory system through the portal vein. Sudan Engineering Society Journal, Vol. 57 (2), pp. 65-77. Sept. 2011 (In Arabic).


  • There are currently no refbacks.

Sudan Eng. Society Journals