Kinetic energy spectrum of low-Reynolds-number turbulence with polymer additives

The effects of polymer additives on the behavior of the kinetic energy spectrum in isotropic decaying turbulence were numerically investigated by hybrid Eulerian-Lagrangian simulations making full use of large-scale parallel computation. The kinetic energy spectrum was found to obey the power-law E(k) similar to k(-alpha) in the range below the Kolmogorov length l(K) when the turbulence decayed. The exponent a satisfied 4 < alpha < 5 and decreased with the increase in the Weissenberg number W-i. The value of a obtained by the largest W-i run was close to the values obtained in previous experimental and numerical studies on elastic turbulence, which is characterized by a larger W-i and a Reynolds number of less than unity. The relationship between the results of the present study and the results obtained for elastic turbulence is also discussed.