Turbulent dynamics of polymer solutions

@article{Balkovsky2000TurbulentDO,
  title={Turbulent dynamics of polymer solutions},
  author={Balkovsky and Fouxon and Lebedev},
  journal={Physical review letters},
  year={2000},
  volume={84 20},
  pages={
          4765-8
        }
}
We study properties of dilute polymer solutions. The probability density function (PDF) of polymer end-to-end extensions R in turbulent flows is examined. We show that if the value of the Lyapunov exponent lambda is smaller than the inverse molecular relaxation time 1/tau then the PDF has a strong peak at the equilibrium size R0 and a power tail at R>>R0. This confirms and extends the results of J. L. Lumley [Symp. Math. 9, 315 (1972)]. There is no essential influence of polymers on the flow in… 

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References

SHOWING 1-10 OF 27 REFERENCES

Mechanical models of dilute polymer solutions in strong flows

In strong flows, such as turbulence, it is suggested that randomly coiled macromolecules might become nearly fully extended. To investigate this extended state, four models are considered which show

Dynamic Properties of an Extended Polymer in Solution

Extended polymers are relevant in a variety of situations ranging from the classic coil-stretch problem to recent single molecule polymer experiments with DNA. We present theoretical calculations and

Polymer stretching by turbulence

  • Chertkov
  • Physics
    Physical review letters
  • 2000
The stretching of a polymer chain by a large-scale chaotic flow is considered. The steady state which emerges as a balance of the turbulent stretching and anharmonic resistance of the chain is

The dynamics of partially extended single molecules of DNA

This work finds that the motion of the DNA can be described by linearly independent normal modes, and it is shown that the spectrum of relaxation times obeys a power law.

Coil-stretch transition of dilute flexible polymers under ultrahigh velocity gradients

Because the hydrodynamic interactions are reduced by stretching, a solute polymer coil should unwind abruptly when a certain critical value of the velocity gradient is reached. Depending on the

Drag reduction in turbulent flow by polymer additives

A brief survey is given of the drag reduction phenomenon, emphasizing the aspects which must be explained by any theory: onset, the existence of intrinsic drag reduction, the Newtonian plug,

Drag Reduction by Additives

An examination is made of the experimental evidence for the reduction of skin friction in dilute solutions of high molecular weight linear polymers below that of the solvent alone. Inferences are

Statistics of a passive scalar advected by a large-scale two-dimensional velocity field: Analytic solution.

The change of variables that allows one to map the matrix problem onto a scalar one is found and to prove the central limit theorem for the stretching rate statistics, valid for any finite correlation time of the velocity field.

Small-Scale Turbulent Dynamo

Kinematic dynamo theory is presented here for turbulent conductive fluids. We describe how inhomogeneous magnetic fluctuations are generated below the viscous scale of turbulence where the spatial

Relaxation of a single DNA molecule observed by optical microscopy.

A rescaling analysis showed that most of the relaxation curves had a universal shape and their characteristic times (lambda t) increased as lambda t approximately L 1.65 +/- 0.13, in qualitative agreement with the theoretical prediction of dynamical scaling.