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Transition to Turbu...
Abstract
Ämnesord
Stäng
- 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.
Ämnesord
- TEKNIK OCH TEKNOLOGIER -- Maskinteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Mechanical Engineering (hsv//eng)
Nyckelord
- Channel flow
- Polymers
- Turbulent flow
- Viscoelasticity
- Bypass transition
- Disturbance field
- Polymer conformation
- Transition regions
- Transition to turbulence
- Turbulence fields
- Turbulent spots
- Turbulent state
- Turbulence
Publikations- och innehållstyp
- ref (ämneskategori)
- kon (ämneskategori)
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