Author
Mohammed Khalij
Other affiliations: Centre national de la recherche scientifique, Nancy-Université
Bio: Mohammed Khalij is an academic researcher from University of Lorraine. The author has contributed to research in topics: Turbulence & Reynolds number. The author has an hindex of 7, co-authored 11 publications receiving 221 citations. Previous affiliations of Mohammed Khalij include Centre national de la recherche scientifique & Nancy-Université.
Papers
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TL;DR: In this paper, the authors derived and validated new correlations for the drag, lift and pitching torque coefficients for non-spherical particles and a large range of Reynolds numbers Rep and aspect ratios w.
115 citations
TL;DR: In this article, the authors compared the available correlations in the literature through a comparison with numerical results of the forces acting on a particle given by a full body-fitted direct numerical simulation (DNS) in the case of a uniform flow, for three different ellipsoidal particles.
80 citations
TL;DR: In this article, the hydrodynamic force and pitching torque acting on the non-spherical particles has been carried out with recent expressions valid outside the Stokes flow regime, with the data extracted from the DNS, a statistical analysis of the particle spatial distribution, orientation, and translational and angular velocities is carried out.
Abstract: Direct numerical simulations (DNSs) have been performed to examine the inertia, shape, and gravity field effects on the dynamics of ellipsoidal particles within a vertical turbulent channel flow. To investigate the effects induced by the particle inertia and shape, computations have been conducted for three aspect ratios and two response times. The influence of gravity has been examined through a comparison with DNS data provided in earlier studies without gravity. The originality of this study is that the prediction of the hydrodynamic force and pitching torque acting on the non-spherical particles has been carried out with recent expressions valid outside the Stokes flow regime. With the data extracted from the DNS, a statistical analysis of the particle spatial distribution, orientation, and translational and angular velocities is carried out. Results show that the presence of a significant mean relative velocity between the dispersed and continuous phases greatly modifies the dynamics of non-spherical...
29 citations
TL;DR: In this paper, the performance of a Probability Density Function (PDF) model for particle temperature statistics in turbulent non-isothermal fully-developed turbulent gas-solid channel flow for a large range of particle inertia was examined.
19 citations
TL;DR: In this article, a model based on accurate modeling of the directional dependence of the fluid Lagrangian time scales is proposed and tested against experimental data in a gas-solid channel flow.
Abstract: In order to investigate the dispersion of small particles in a turbulent shear flow, a new model based on accurate modelling of the directional dependence of the fluid Lagrangian time scales is proposed and tested against experimental data in a gas–solid channel flow. The continuum phase is described by a nonlinearlow-Reynolds k-ϵ model, thus allowing a fine description of turbulence anisotropy and near-wall effects. The dispersed phase is described by a Lagrangian stochastic method, which is formulated in order to take into account the nonhomogeneity and the anisotropy of turbulence. The fluid Lagrangian time scales in each direction are assessed following a recent proposal supported by channel flow DNS computations. The integral time scales of the fluid seen by the particles are then estimated in taking the inertia and crossing trajectory effects into account. The numerical predictions (particle and fluid statistical quantities) obtained by means of this time scale model and previously available time sc...
16 citations
Cited by
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TL;DR: Anisotropic particles are common in many industrial and natural turbulent flows as discussed by the authors, and when these particles are small and neutrally buoyant, they follow Lagrangian trajectories while exhibiting rich orientational dynamics from the coupling of their rotation to the velocity gradients of the turbulence field.
Abstract: Anisotropic particles are common in many industrial and natural turbulent flows. When these particles are small and neutrally buoyant, they follow Lagrangian trajectories while exhibiting rich orientational dynamics from the coupling of their rotation to the velocity gradients of the turbulence field. This system has proven to be a fascinating application of the fundamental properties of velocity gradients in turbulence. When particles are not neutrally buoyant, they experience preferential concentration and very different preferential alignment than neutrally buoyant tracer particles. A vast proportion of the parameter range of anisotropic particles in turbulence is still unexplored, with most existing research focusing on the simple foundational cases of axisymmetric ellipsoids at low concentrations in homogeneous isotropic turbulence and in turbulent channel flow. Numerical simulations and experiments have recently developed a fairly comprehensive picture of alignment and rotation in these cases, and t...
257 citations
TL;DR: In this article, the authors present an exhaustive overview of the main experimental papers dealing with underexpanded jets, from those where there is clearly a lack of confidence, and some clues are given on the numerical methods that may be used if one wants to study such jets numerically, together with an emphasis on the specific thermodynamic difficulties associated to this kind of extreme conditions.
189 citations
TL;DR: In this paper, the authors derived and validated new correlations for the drag, lift and pitching torque coefficients for non-spherical particles and a large range of Reynolds numbers Rep and aspect ratios w.
115 citations
TL;DR: In this article, the drag, lift and torque coefficients of non-spherical particles were determined using the lattice Boltzmann method with multi-relaxation time in the Reynolds number range 0.1 to 2.1 for different incident angles ϕ.
110 citations
TL;DR: The Stokes-Newton equation was proposed in this article as a landmark for the relation between the drag coefficient and the Reynolds number, and the results of this landmark correlation were cross-compared with the estimates of the direct and indirect correlations and with the data set of the historical Standard Drag Curve.
72 citations