{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,7]],"date-time":"2025-10-07T11:48:33Z","timestamp":1759837713322},"reference-count":28,"publisher":"Cambridge University Press (CUP)","license":[{"start":{"date-parts":[[2006,4,26]],"date-time":"2006-04-26T00:00:00Z","timestamp":1146009600000},"content-version":"unspecified","delay-in-days":5474,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Fluid Mech."],"published-print":{"date-parts":[[1991,5]]},"abstract":"<jats:p>Measurements of wall pressure, and mean and r.m.s. velocities of the confined flow about a disk of 50 % area blockage have been carried out for two Newtonian fluids and four concentrations of a shear-thinning weakly elastic polymer in aqueous solution encompassing a Reynolds-number range from 220 to 138000. The flows of Newtonian and non-Newtonian fluids were found to be increasingly dependent on Reynolds numbers below 50000, with a decrease in the length of the recirculation region and dampening of the normal Reynolds stresses. At Reynolds numbers less than 25000, the recirculation bubble lengthened and all turbulence components were suppressed with increased polymer concentration so that, at a Reynolds number of 8000, the maximum values of turbulent kinetic energy were 35 and 45% lower than that for water, with 0.2% and 0.4% solutions of the polymer. Non-Newtonian effects were found to be important in regions of low local strain rates in low-Reynolds-number flows, especially inside the recirculation bubble and close to the shear layer, and are represented by both an increase in viscous diffusion and a decrease in turbulent diffusion to, respectively, 6% and 18% of the largest term of the momentum balance with a 0.4 % polymer solution at a Reynolds number of 7700. The asymmetry and unsteadiness of the flow at Reynolds numbers between 400 and 6000 is shown to be an aerodynamic effect which increases in range and amplitude with the more concentrated polymer solutions.<\/jats:p>","DOI":"10.1017\/s0022112091002471","type":"journal-article","created":{"date-parts":[[2006,4,26]],"date-time":"2006-04-26T14:36:47Z","timestamp":1146062207000},"page":"475-496","source":"Crossref","is-referenced-by-count":11,"title":["Flow of non-Newtonian fluids over a confined baffle"],"prefix":"10.1017","volume":"226","author":[{"given":"F. T.","family":"Pinho","sequence":"first","affiliation":[]},{"given":"J. H.","family":"Whitelaw","sequence":"additional","affiliation":[]}],"member":"56","published-online":{"date-parts":[[2006,4,26]]},"reference":[{"key":"S0022112091002471_ref019","unstructured":"Nouri, J. M. :1988 Single and two-phase flows in ducts and stirred reactors. Ph.D. thesis,University of London."},{"key":"S0022112091002471_ref004","doi-asserted-by":"crossref","unstructured":"Berman, N. S :1978 Drag reduction by polymers.Ann. Rev. Fluid Mech. 10,47.","DOI":"10.1146\/annurev.fl.10.010178.000403"},{"key":"S0022112091002471_ref017","doi-asserted-by":"crossref","unstructured":"Metzner, A. B. & Metzner, A. P. ,1970 Stress levels in rapid extensional flows of polymeric fluids.Rheol. Ada 9,174.","DOI":"10.1007\/BF01973476"},{"key":"S0022112091002471_ref028","doi-asserted-by":"crossref","unstructured":"Yianneskis, M. , Popiolek, Z. & Whitelaw, J. H. ,1987 An experimental study of the steady and unsteady flow characteristics of stirred reactors.J. Fluid Mech. 175,537.","DOI":"10.1017\/S002211208700051X"},{"key":"S0022112091002471_ref025","doi-asserted-by":"crossref","unstructured":"Tsai, C. F. & Darby, R. ,1978 Non Linear viscoelastic properties of very dilute drag reducing polymer solutions.J. Rheol. 22,219.","DOI":"10.1122\/1.549480"},{"key":"S0022112091002471_ref022","doi-asserted-by":"crossref","unstructured":"Pinho, F. T. & Whitelaw, J. H. ,1990 Flow of non-Newtonian fluids in a pipe.J. Non-Newtonian Fluid Mech. 34,129.","DOI":"10.1016\/0377-0257(90)80015-R"},{"key":"S0022112091002471_ref005","unstructured":"De Bruijn, R. A. :1987 Inelastic shear-thinning model liquids.Unilever Rep. PA\/7306\/mk."},{"key":"S0022112091002471_ref011","doi-asserted-by":"crossref","unstructured":"Hinch, E. J. :1977 Mechanical models of dilute polymer solutions in strong flows.Phys. Fluids Suppl. 20 S22.","DOI":"10.1063\/1.861735"},{"key":"S0022112091002471_ref024","unstructured":"Taylor, A. M. K. P. & Whitelaw, J. H. 1984 Velocity characteristics in the turbulent near wakes of confined axisymmetric bluff bodies.J. Fluid Mech. 139,391."},{"key":"S0022112091002471_ref015","unstructured":"Larsen, P. S. & Christensen, E. M. ,1985 Velocity distributions of water and viscarin solutions in straight channel.Technical University of Denmark, Dept of Fluid Mechanics. Rep. AFM 85\u201305."},{"key":"S0022112091002471_ref008","doi-asserted-by":"crossref","unstructured":"Dairenieh, I. S. & McHugh, A. J. ,1985 Viscoelastic fluid flow past a submerged spheroidal body.J. Non-Newtonian Fluid Mech. 19,81.","DOI":"10.1016\/0377-0257(85)87013-0"},{"key":"S0022112091002471_ref013","doi-asserted-by":"crossref","unstructured":"Kwade, M. :1982 Beeinflussung der Turbulenzstruktur in der Ebenen Mischungsschicht zweier Str\u00f6me durch Polymerzus\u00e4tze.Rheol. Acta 21,120.","DOI":"10.1007\/BF01736413"},{"key":"S0022112091002471_ref006","doi-asserted-by":"crossref","unstructured":"Calvert, J. R. :1967 Experiments on the low speed flow past cones.J. Fluid Mech. 27,273.","DOI":"10.1017\/S002211206700031X"},{"key":"S0022112091002471_ref021","unstructured":"Pinho, F. T. & Whitelaw, J. H. ,1988 Flow characteristics of a non-Newtonian fluid. In 4th Intl Symp. on Applications of Laser Anemometry to Fluid Mech., 11\u201314 July 1988, Lisbon (ed. D. F. G. Durao , R. J. Adrian , T. Asanuma , F. Durst & J. H. Whitelaw ), Paper 1.23."},{"key":"S0022112091002471_ref002","doi-asserted-by":"crossref","unstructured":"Aecoumanis, C. , Hadjiapostolou, A. & Whitelaw, J. H. ,1987 Swirl center precession in engine flows.Soc. Automotive Bngrs. Paper 870370.","DOI":"10.4271\/870370"},{"key":"S0022112091002471_ref026","doi-asserted-by":"crossref","unstructured":"White, D. A. :1967 Velocity measurements in axisymmetric jets of dilute polymer solutions.J. Fluid Mech. 28,195.","DOI":"10.1017\/S0022112067001995"},{"key":"S0022112091002471_ref023","unstructured":"Srvasegaram, S. & Whitelaw, J. H. ,1985 Vortex shedding in disk stabilised flames. Internal Rep. FS\/85\/01 .Imperial College,London."},{"key":"S0022112091002471_ref014","doi-asserted-by":"crossref","unstructured":"Koziol, K. & Glowacki, P. ,1989 Turbulent jets of dilute polymer solutions.J. Non-Newtonian Fluid Mech. 32,311.","DOI":"10.1016\/0377-0257(89)85013-X"},{"key":"S0022112091002471_ref007","doi-asserted-by":"crossref","unstructured":"Cherdron, W. , Durst, F. & Whitelaw, J. H. ,1978 Asymmetric flows and instabilities in symmetric ducts with sudden expansions.J. Fluid Mech. 84,13.","DOI":"10.1017\/S0022112078000026"},{"key":"S0022112091002471_ref003","doi-asserted-by":"crossref","unstructured":"Barker, S. J. :1973 Laser Doppler measurements on a round turbulent jet in dilute polymer solutions.J. Fluid Mech. 60,721.","DOI":"10.1017\/S0022112073000431"},{"key":"S0022112091002471_ref001","doi-asserted-by":"crossref","unstructured":"Adachi, K. , Yoshioka, N. & Sakai, K. ,1977\/78 An investigation of non-Newtonian flow past a sphere.J. Non-Newtonian Fluid Mech.,3,107.","DOI":"10.1016\/0377-0257(77)80044-X"},{"key":"S0022112091002471_ref016","unstructured":"Mena, B. , Manero, O. & Leal, L. G. 1987 The influence of rheological properties on the slow flow past spheres.J. of Non-Newtonian Fluid Mech. 26,247."},{"key":"S0022112091002471_ref009","doi-asserted-by":"crossref","unstructured":"Ftjjii, S. , Gomi, M. & Eguchi, K. ,1978 Cold flow tests of a bluff flame stabilizer.Trans. ASME I: J. Fluids Engng. 100,323.","DOI":"10.1115\/1.3448673"},{"key":"S0022112091002471_ref012","unstructured":"Hockey, R. , Nouri, J. M. & Pinho, F. T. ,1989 Flow visualization of Newtonian and non-Newtonian fluids in a stirred reactor. In5th Intl Symp. on Flow Visualization, Praha, CSSR, August 21\u201325."},{"key":"S0022112091002471_ref020","unstructured":"Nouri, J. M. & Whitelaw, J. H. & Yianneskis, M. 1987 Particle motion and turbulence in dense two-phase flows.Intl. J. Multiphase Flow 13,729."},{"key":"S0022112091002471_ref010","unstructured":"Ghorashi, B. & Hirsch, D. ,1987 Laminar flow of a non-Newtonian fluid in a heated pipe.Cleveland State University, Chem Engng Rep."},{"key":"S0022112091002471_ref027","doi-asserted-by":"crossref","unstructured":"Willmarth, W. W. , Wei, T. & Lee, C. O. ,1987 Laser anemometer measurements in turbulent channel flow with drag reducing polymer additives.Phys. Fluids 30,933.","DOI":"10.1063\/1.866278"},{"key":"S0022112091002471_ref018","doi-asserted-by":"crossref","unstructured":"Nakano, A. & Minouha, Y. ,1975 Effects of solvent and concentration on scission of polymers at high speed stirring.J. Appl. Polymer Sci.,19,2119.","DOI":"10.1002\/app.1975.070190806"}],"container-title":["Journal of Fluid Mechanics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0022112091002471","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,6,6]],"date-time":"2019-06-06T13:53:49Z","timestamp":1559829229000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0022112091002471\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1991,5]]},"references-count":28,"alternative-id":["S0022112091002471"],"URL":"https:\/\/doi.org\/10.1017\/s0022112091002471","relation":{},"ISSN":["0022-1120","1469-7645"],"issn-type":[{"value":"0022-1120","type":"print"},{"value":"1469-7645","type":"electronic"}],"subject":[],"published":{"date-parts":[[1991,5]]}}}