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Linear stability of the flow of a second order fluid past a wedge
- Publication Year :
- 2020
- Publisher :
- American Institute of Physics (AIP), 2020.
-
Abstract
- The linear stability analysis of Rivlin–Ericksen fluids of second order is investigated for boundary layer flows, where a semi-infinite wedge is placed symmetrically with respect to the flow direction. Second order fluids belong to a larger family of fluids called order fluids, which is one of the first classes proposed to model departures from Newtonian behavior. Second order fluids can model non-zero normal stress differences, which is an essential feature of viscoelastic fluids. The linear stability properties are studied for both signs of the elasticity number K, which characterizes the non-Newtonian response of the fluid. Stabilization is observed for the temporal and spatial evolution of two-dimensional disturbances when K > 0 in terms of increase of critical Reynolds numbers and reduction of growth rates, whereas the flow is less stable when K < 0. By extending the analysis to three-dimensional disturbances, we show that a positive elasticity number K destabilizes streamwise independent waves, while the opposite happens for K < 0. We show that, as for Newtonian fluids, the non-modal amplification of streamwise independent disturbances is the most dangerous mechanism for transient energy growth, which is enhanced when K > 0 and diminished when K < 0.
- Subjects :
- Fluid Flow and Transfer Processes
Physics
Mechanical Engineering
Computational Mechanics
Reynolds number
Mechanics
Flow direction
Condensed Matter Physics
01 natural sciences
Wedge (geometry)
Viscoelasticity
010305 fluids & plasmas
Physics::Fluid Dynamics
symbols.namesake
Boundary layer
Mechanics of Materials
0103 physical sciences
symbols
Spatial evolution
010306 general physics
Second-order fluid
Linear stability
Subjects
Details
- Language :
- English
- ISSN :
- 10706631
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....37de5b860ded32393277c0e432e1c7b1