TY - GEN
T1 - Variance amplification in channel flows of strongly elastic polymer solutions
AU - Jovanović, Mihailo R.
AU - Kumar, Satish
PY - 2009
Y1 - 2009
N2 - This paper identifies a new mechanism for amplification of stochastic disturbances in channel flows of strongly elastic polymer solutions. For streamwise constant flows with high elasticity numbers μ and non-vanishing Reynolds numbers Re, the O(μRe3) scaling of the variance amplification is established using singular perturbations techniques. This demonstrates that large variances can be maintained in stochastically driven flows occurring in weak inertial/strong elastic regimes. Mathematically, the amplification arises due to nonnormality of the governing equations and, physically, it is caused by the stretching of the polymer stresses by the background shear. The reported developments provide a possible route for a bypass transition to 'elastic turbulence' and suggest a novel method for efficient mixing in micro-fabricated straight channels.
AB - This paper identifies a new mechanism for amplification of stochastic disturbances in channel flows of strongly elastic polymer solutions. For streamwise constant flows with high elasticity numbers μ and non-vanishing Reynolds numbers Re, the O(μRe3) scaling of the variance amplification is established using singular perturbations techniques. This demonstrates that large variances can be maintained in stochastically driven flows occurring in weak inertial/strong elastic regimes. Mathematically, the amplification arises due to nonnormality of the governing equations and, physically, it is caused by the stretching of the polymer stresses by the background shear. The reported developments provide a possible route for a bypass transition to 'elastic turbulence' and suggest a novel method for efficient mixing in micro-fabricated straight channels.
KW - Elastic turbulence
KW - Microfluidic mixing
KW - Polymer additives
KW - Singular perturbations
KW - Variance amplification
KW - Viscoelastic fluids
UR - http://www.scopus.com/inward/record.url?scp=70449627812&partnerID=8YFLogxK
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U2 - 10.1109/ACC.2009.5160632
DO - 10.1109/ACC.2009.5160632
M3 - Conference contribution
AN - SCOPUS:70449627812
SN - 9781424445240
T3 - Proceedings of the American Control Conference
SP - 842
EP - 847
BT - 2009 American Control Conference, ACC 2009
T2 - 2009 American Control Conference, ACC 2009
Y2 - 10 June 2009 through 12 June 2009
ER -