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Seminar: Fluid Mechanics

Transition to turbulence in pipe flow of Non-Newtonian solutions

Speaker: Devranjan Samanta
Organization: Indian Institute of Technology Ropar
Time: 2018-06-14 10:30
Place: Teknikringen 8

Abstract

The transition to turbulence in pipe flow with dilute polymer solutions has been investigated. Compared to the Newtonian case, transition is delayed. At higher concentrations however Newtonian like transition disappears. Instead disordered motion sets in globally and onset of transition is independent of additional perturbation to the flow. This new type of instability , a combined effect of elastic and inertial effects, termed as elasto-inertial instability sets in and ultimately results in the asymptotic state of maximum drag reduction (MDR). Most strikingly disordered motion is observed at much lower Re than Newtonian turbulence.