Hybrid simulations for the mechanical degradation of polymer solution by turbulence

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In this study we examined the mechanical degradation of polymer solution by turbulence and its effects on turbulence statistics by performing the numerical simulations which include the cut-off process of long-chain polymers. It is known that the kinetic energy dissipation of turbulent flows is reduced by polymer additives. It was found that the longer chain polymers have larger influence on the turbulence statistics like the kinetic energy dissipation. When the elasticity of polymers was much stronger, turbulent motions were maintained by stretching polymers even when the turbulence sufficiently decayed. Then the kinetic energy spectrum showed the characteristic power-law decay in the wavenumber range below the Kolmogorov scale. We also found that the reduction rate of the kinetic energy dissipation was gradually decreased with time due to the decreasing of the number of longer chain polymers by cutting.