Manifestations of Drag Reduction by Polymer Additives in Decaying, Homogeneous, Isotropic Turbulence

Perlekar, Prasad; Mitra, Dhrubaditya; Pandit, Rahul

doi:10.1103/physrevlett.97.264501

Cited by 107 publications

(97 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dependence of DR on the polymer concentration parameter c and the Weissenberg number may be found in Ref. [138]. Here we show how the addition of polymers reduces smallscale structures in the turbulent flow: By a comparison of the isosurfaces of |ω| in the left (without polymers) and right (with polymers) panels of Fig.…”

Section: Turbulence With Polymer Additivesmentioning

confidence: 99%

“…In this Subsection, we present a few results from our numerical study [138] of the analogue drag reduction by polymer additives in homogeneous, isotropic turbulence. This requires a DNS of considerably greater complexity than the ones we have described above.…”

Section: Turbulence With Polymer Additivesmentioning

confidence: 99%

“…We have employed a numerical technique that uses a Cholesky decomposition to overcome this problem; we refer the reader to Ref. [138] for these details.…”

Section: Turbulence With Polymer Additivesmentioning

confidence: 99%

See 2 more Smart Citations

Statistical properties of turbulence: An overview

2009

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Turbulence With Polymer Additivesmentioning

confidence: 99%

Section: Turbulence With Polymer Additivesmentioning

confidence: 99%

See 1 more Smart Citation

Statistical properties of turbulence: An overview

2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…(2), we follow the two References [61,62] to solve the FENE-P equation. The polymer feedback stress is computed from the FENE-P evolution equation and used to change the shear modes of the LB [41,52,53].…”

Section: Hybrid Lattice Boltzmann (Lb) Modelsfinite Difference (Fd) Smentioning

confidence: 99%

A lattice Boltzmann study of the effects of viscoelasticity on droplet formation in microfluidic cross-junctions

Gupta

Sbragaglia

2016

Eur. Phys. J. E

View full text Add to dashboard Cite

Abstract. Based on mesoscale lattice Boltzmann (LB) numerical simulations, we investigate the effects of viscoelasticity on the break-up of liquid threads in microfluidic cross-junctions, where droplets are formed by focusing a liquid thread of a dispersed (d) phase into another co-flowing continuous (c) immiscible phase. Working at small Capillary numbers, we investigate the effects of non-Newtonian phases in the transition from droplet formation at the crossjunction (DCJ) to droplet formation downstream of the cross-junction (DC) (Liu & Zhang, Phys. Fluids. 23, 082101 (2011)). We will analyze cases with Droplet Viscoelasticity (DV), where viscoelastic properties are confined in the dispersed phase, as well as cases with Matrix Viscoelasticity (MV), where viscoelastic properties are confined in the continuous phase. Moderate flow-rate ratios Q ≈ O(1) of the two phases are considered in the present study. Overall, we find that the effects are more pronounced with MV, where viscoelasticity is found to influence the break-up point of the threads, which moves closer to the cross-junction and stabilizes. This is attributed to an increase of the polymer feedback stress forming in the corner flows, where the side channels of the device meet the main channel. Quantitative predictions on the break-up point of the threads are provided as a function of the Deborah number, i.e., the dimensionless number measuring the importance of viscoelasticity with respect to Capillary forces.

show abstract

“…As for the polymer evolution given in Eq. (2), we follow the two References [65,66] to solve the FENE-P equation. The polymer stress f (r P )C is computed from the FENE-P evolution equation and used to change the shear modes of the LBM [43,57,58].…”

Section: A Hybrid Lattice Boltzmann Models (Lbm) -Finite Difference Smentioning

confidence: 99%

Effects of viscoelasticity on droplet dynamics and break-up in microfluidic T-Junctions: a lattice Boltzmann study

Gupta

Sbragaglia

2016

Eur. Phys. J. E

View full text Add to dashboard Cite

Abstract. The effects of viscoelasticity on the dynamics and break-up of fluid threads in microfluidic T-junctions are investigated using numerical simulations of dilute polymer solutions at changing the Capillary number (Ca), i.e. at changing the balance between the viscous forces and the surface tension at the interface, up to Ca ≈ 3 × 10 −2 . A NavierStokes (NS) description of the solvent based on the lattice Boltzmann models (LBM) is here coupled to constitutive equations for finite extensible non-linear elastic dumbbells with the closure proposed by Peterlin (FENE-P model). We present the results of three-dimensional simulations in a range of Ca which is broad enough to characterize all the three characteristic mechanisms of breakup in the confined T-junction, i.e. squeezing, dripping and jetting regimes. The various model parameters of the FENE-P constitutive equations, including the polymer relaxation time τ P and the finite extensibility parameter L 2 , are changed to provide quantitative details on how the dynamics and break-up properties are affected by viscoelasticity. We will analyze cases with Droplet Viscoelasticity (DV), where viscoelastic properties are confined in the dispersed (d) phase, as well as cases with Matrix Viscoelasticity (MV), where viscoelastic properties are confined in the continuous (c) phase. Moderate flow-rate ratios Q ≈ O(1) of the two phases are considered in the present study. Overall, we find that the effects are more pronounced in the case with MV, as the flow driving the break-up process upstream of the emerging thread can be sensibly perturbed by the polymer stresses.

show abstract

Manifestations of Drag Reduction by Polymer Additives in Decaying, Homogeneous, Isotropic Turbulence

Cited by 107 publications

References 31 publications

Statistical properties of turbulence: An overview

Statistical properties of turbulence: An overview

A lattice Boltzmann study of the effects of viscoelasticity on droplet formation in microfluidic cross-junctions

Effects of viscoelasticity on droplet dynamics and break-up in microfluidic T-Junctions: a lattice Boltzmann study

Contact Info

Product

Resources

About