Transition to Turbulence in Viscoelastic Channel Flow
2015 (English)In: Procedia IUTAM, Elsevier, 2015, 519-526 p.Conference paper (Refereed)
The influence of viscoelasticity on bypass transition to turbulence in channel flow is studied using data from direct numerical simulations by Agarwal et al. (2014) 1. The initial field is a superposition of a laminar base state and a localized disturbance. Relative to the Newtonian conditions, the polymeric FENE-P flow delays the onset of transition and extends its duration. The former effect is due to a weakening of the pre-transitional disturbance field, while the prolonged transition region is due to a slower spreading rate of the turbulent spots. Once turbulence occupies the full channel, a comparison of the turbulence fields shows that energetic flow structures are longer and wider in the polymeric flow. The final turbulent state is compared to elasto-inertial turbulence (EIT), where the polymer conformation field takes the form of elongated sheets with wide spanwise extent. © 2015 The Authors.
Place, publisher, year, edition, pages
Elsevier, 2015. 519-526 p.
Channel flow, Polymers, Turbulent flow, Viscoelasticity, Bypass transition, Disturbance field, Polymer conformation, Transition regions, Transition to turbulence, Turbulence fields, Turbulent spots, Turbulent state, Turbulence
IdentifiersURN: urn:nbn:se:kth:diva-176124DOI: 10.1016/j.piutam.2015.03.083ISI: 000380499200060ScopusID: 2-s2.0-84940666204OAI: oai:DiVA.org:kth-176124DiVA: diva2:866197
8th IUTAM-ABCM Symposium on Laminar Turbulent Transition, LTT 2014, 8 September 2014 through 12 September 2014
QC 201511022015-11-022015-11-022016-08-30Bibliographically approved