Toms effect

The first reports on the drag reduction phenomenon are found in publications by Blatch (1906), Forrest (1931), as well as by Brautlecht (1933), who measured the flow behaviour of paper pulps. In independent studies made by Mysels (1949) and Toms (1948) this phenomenon was observed in the turbulent flow of gasoline in pipes when aluminum soaps were added and, in Toms experiments, when polymethylmethacrylate in monochlorobenzene was used. The reduction of friction is therefore often termed the Toms effect . This flow behaviour is also known in the literature as the Non-Newtonian- , visco-elastic- , Texas- or Texas-Toms-effect , due to the contributions made by Texan researchers. It is also more generally known, and this term will be used in this paper exclusively, as the drag-reduction effect of flow additives. 

Fabula AG, Lumley JC, Taylor WD (1966) Some interpretations of the Toms-effect in Modem development in the mechanics of continua ed Eskinazi S, Academic Press, New York, p. 145... 

Lockett FJ (1964) Fluid dynamics approach to the Toms effect Nature 222 937... 

Vlasak P. (1995), The Toms effect in capsule-liquid flows, In 8th Int. Freight Pipeline Society Symposium , p. 93. 

Fabula, A.G. Lumley, J.L. Taylor, W.D. Some interpretations of the Toms effect. In Modem Developments in the Mechanics of continua. Proceedings of the International Conference on Rheology, Pinebrook, New York, Aug 23-27, 1965 Eskanazi, S., Ed. Academic Press New York, 1966 145-164. 

The Toms effect is essentially dependent on the molecular parameters of the dissolved additive the most important of these are the molecular weight and the molecular weight distribution. In this paper the influence of these parameters in the case of water-soluble polymers is. investigated, whereby experiments were carried out with extremely pure laboratory polyacrylamides (PAAm). ... 

Fig.3. Value of Toms effect vs. elasticity of macromolecular chains...

Anisimov, I.A. Mironov, B.P. Dependence of Toms effect on size of polymer macromolecules. In "Vliyanie polimernykh dobavok i uprugosti poverkhnosti na pristennuyu turbu-lentnost", ITF, Novosibirsk, 1978, p. 7-15. 

The importance of "drag reduction" as it is called today -another name for it being "Toms effect" - seems to have been overlooked for quite a number of years, and it was not until the late fifties that scientists started their interest in it. 

Ahrnbom/ L./ Hagstrand/ U. Toms effect in district heating system. Full scale demonstration test. Varmeteknisk Forsknung/ projekt P-56/ 1980... 

Subsequently, in the effort to extent the Toms effect to other polymers, a series of polysaccharides from aquatic plants, microscopic algae, and bacteria were been investigated. Interesting results were found by J.W. Hoyt [1063] and P. Kenis [1071-1073]. 

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