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Universal spectrum in the infrared range of two-dimensional turbulent flows Phys. Fluids 26, 025105 (2014); 10.1063/1.4864103Eddy damped quasinormal Markovian simulations of superfluid turbulence in helium II An eddy damped quasi-normal Markovian closure model coupled to a differential approximation model suggested in L'vov, Nazarenko, and Rudenko ["Gradual eddywave crossover in superfluid turbulence," J. Low Temp. Phys. 153, 140 (2008)] is proposed to simulate the full unsteady dynamics of superfluid turbulence from largescale hydrodynamic eddy motion to Kelvin waves that occur on quantized vortices in He III-B at very low temperature. The present model accounts for eddy-wave interactions over crossover scales, and coupling with the two existing models for the Kelvin wave cascade (L'vov and Nazarenko model [V. S L'vov and S. Nazarenko, "Spectrum of Kelvin wave turbulence in superfluids," JETP Lett. 91, 428-434 (2010)] or Kozik and Svistunov model [E. Kozik and B. Svistunov, "Kelvin wave cascade and decay of superfluid turbulence," Phys. Rev. Lett. 92, 035301 (2004)]), are considered. Hydrodynamic kinetic energy spectrum and Kelvin wave energy spectrum are solved separately, allowing for a deep insight into flow physics. A detailed analysis of the bottleneck phenomena is performed thanks to a systematic investigation of the crossover region and the Kelvin cascade model. It is observed that both the shape and the width of the bottleneck region are governed by the eddy-wave interaction model. It is concluded that the bottleneck is robust in the sense that it is observed in all cases, but that a detailed description escapes both present direct numerical simulation and experimental capabilities. C 2012 American Institute of Physics. [http://dx.

International audienceA RANS zonal pseudo-homogeneous 1D radial heat transfer model is derived using an homogenization technique along with high-fidelity microscopic simulation to calibrate the model free parameters. Thus, it is brought to light the importance of the mechanical dispersion in the mixing process, the similarity between turbulent and dispersive dynamics, the existence of a near wall zone characterized by a channeling effect which is responsible for the thermal resistance over the zone. A linear law for the effective thermal conductivity is proposed to assess the heat transfer within the disrupted thermal boundary layer. The model showed its ability to estimate the effective conductivity and the temperature field in the radial direction with satisfaction. Very good agreements are also found in the near wall zone where the temperature gradients are the highest. The model well estimated also the value of the wall temperature and the wall heat transfer coefficient for an imposed heat flux at the wall