We compute analytically the probability distribution function P(ε) of the dissipation field ε = (∇θ)2 of a passive scalar θ advected by a d-dimensional random flow, in the limit of large Peclet and Prandtl numbers (Batchelor-Kraichnan regime). The tail of the distribution is a stretched exponential: for ε → ∞, lnP(ε) ∼ −(d2ε)1/3. PACS numbers: 47.10.+g, 47.27.-i, 05.40.+j

The present research examines the joint influence of throughflow and Coriolis force on onset double-diffusive convection with an internal heat source modelled by Darcy’s law. BVP4C routine in MATLAB R2020a is used to solve eigenvalue problem numerically. Critical Rayleigh numbers are obtained for designated values governing parameters. effect parameter, Taylor number, Darcy Peclet number system...

A theoretical model is proposed to predict Darcy-scale mass transport in porous media coupled with nonequilibrium heat transfer and taking into account the thermal diffusion process. volume-averaging technique was used approximations leading a two-equation or two-temperature for macroscale energy balance equations. Because of Soret effect, concentration deviation respect averaged value function...

Chromium (VI) (Cr(VI)) contamination of soil and groundwater is considered a major environmental concern. Bioreduction of Cr(VI) to chromium (III) (Cr(III)) can be considered an effective technology in remediating Cr(VI) contaminated sites. Among the Cr(VI) reducing bacteria, Shewanella oneidensis MR-1 (MR-1) is relatively effective. Reduction of Cr(VI) by MR-1 is defined by the dual-enzyme kin...

Expanding interest in enhanced subsurface natural resource recovery and carbon sequestration motivates study of reacting flows in porous media. In this work, we examine the case of reaction products that increase or decrease the viscosity of the fluid. Parallel reactant streams flow through porous media and react transversely along the centerline. We utilize a pore scale, finite element numeric...

The mechanism of displacement washing of packed bed of porous, compressible and cylindrical particles, e.g., fibers, is presented with the help of an axial dispersion model involving Peclet number (Pe) and Biot number (Bi). Bulk fluid concentration, intra-pore solute concentration and concentration of solute adsorbed on the fiber surface are taken to be the function of washing time and position...

For a wide range of applications of graphene suspensions, a thorough understanding of their rheological properties is crucial. We probe the microstructure of dense suspensions of micron-sized, few-layer, defect-free graphene platelets by measuring their viscoelastic properties at various concentrations up to 39 mg ml(-1). We propose a model to relate the yield strain to the mesh size of the mic...

A backmixing-diffusion model was developed and proposed to describe the mass transport in a reversing continuous countercurrent extractor (RCCE) at steady-state condition. Three variables namely draft, retention time, and extraction temperature were studied according to various experimental trials. Equilibrium distribution coefficient and solute diffusivity were important parameters introduced ...