Toms effect
In fluid dynamics, the Toms effect is a reduction of the drag of a turbulent flow thought a pipeline when polymer solutions are added.[1]
In 1948, B. A. Toms discovered[2] by experiments that the addition of a small amount of polymer into a Newtonian solvent (parts per million by weight), which results in a non-Newtonian fluid solution, can reduce the skin frictional drag on a stationary surface by up to 80% when turbulence is present.[1]
This technology has been successfully implemented to reduce pumping cost for oil pipelines, to increase the flow rate in fire fighting equipment and to help irrigation and drainage.[3][4] It also has potential applications in the design of ship and submarine hulls to achieve an increased speed and reduced energy cost.
See also
[edit]External links
[edit]References
[edit]Perlekar P, Mitra D, Pandit R. Manifestations of drag reduction by polymer additives in decaying, homogeneous, isotropic turbulence. Physical review letters. 2006. [1]
Jin S 2007 Numerical simulations of a dilute polymer solution in isotropic turbulence PhD Thesis Cornell University, Ithaca, NY
Liberzon A., Guala M., Lüthi B., Kinzelbach W. and Tsinober A. Dilute polymers in turbulence Physics of Fluids, 17, 031707, 2005 link
Liberzon A., Guala M., Kinzelbach W., and Tsinober A. On turbulent kinetic energy production and dissipation in dilute polymer solutions Physics of Fluids 18, 125101, 2006 link
Liberzon A., Guala M., Holzner M., Lüthi B., and Kinzelbach W. On turbulent entrainment and dissipation in dilute polymer solutions, Physics of Fluids, 21, 035107, 2009 link
- ^ a b Graebel, William (2001-01-19). Engineering Fluid Mechanics. CRC Press. ISBN 978-1-56032-733-2.
- ^ Toms, B. A. 1948 Some Observation on the flow of linear polymer solutions through straight tubes at large Reynolds numbers. Proc. Int’l Rheological Congress 2, 135–141
- ^ Sellin, R. H. J. & Ollis, M. 1980 Polymer drag reduction in large pipes and sewers: Results of recent field trials. Journal of Rheology
- ^ Khalil, M. F., Kassab, S. Z., Elmiligui, A. A. & Naoum, F. A. 2002 Applications of drag-reducing polymers in sprinkler irrigation systems: Sprinkler head performance. Journal of Irrigation and Drainage Engineering