Hawa Singh¹, Paras Ram², Vikas Kumar³

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 521-550, 2014, DOI:10.3970/fdmp.2014.010.521

Abstract The fluctuating flow produced by magneto - hydrodynamic free convection past an impulsively started isothermal vertical plate is studied taking into account the effects of radiation and viscous dissipation. By using the similarity transformation, the governing equations are transformed into dimensionless form and then the system of nonlinear partial differential equations is solved by a perturbation technique. The considered uniform magnetic field acts perpendicular to the plate, which absorbs the fluid with a given suction velocity. A comparison is made in velocity and temperature profiles for two particular cases of real and imaginary time dependent functions. The effects of various… More >

Gnaneswara Reddy Machireddy¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.4, pp. 417-442, 2014, DOI:10.3970/fdmp.2014.010.417

Abstract This study deals with the investigation of the effects exerted by heat radiation and a first-order chemical reaction on the magnetohydrodynamics boundary layer slip flow which is established past a vertical permeable surface embedded in a porous medium (with uniform heat and mass flux). The heat equation includes the relevant terms, i.e. the viscous dissipation, radiative heat flux, Ohmic dissipation, and absorption of radiation. The mass transfer equation takes into account the effects related to the chemically reactive species. A classical model for optically thin media is used for studying the effect of radiation. The resulting non-linear coupled partial differential… More >

Edoardo Bucchignani¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.1, pp. 37-60, 2009, DOI:10.3970/fdmp.2009.005.037

Abstract This article describes an implicit method for the solution of time dependent Navier-Stokes equations written in terms of vorticity and velocity. The field equations are discretized using a finite volume technique over quadrilateral meshes.
The numerical code has been applied to the classical window cavity test, employing a fine stretched non-uniform grid, in order to provide an accurate steady solution for a high value of the Rayleigh number (10⁸). It has also been performed a simulation for a value of Rayleigh larger than the critical value, in order to show the capabilities of the proposed method to properly simulate… More >

I. Ueno¹, T. Kishida²

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.1, pp. 55-60, 2008, DOI:10.3970/fdmp.2008.004.055

Abstract Phenomenon known as `tears of wine' arises on an inclined plate partially submerged in a bulk of alcohol-water mixture. This phenomenon apparently exhibits a periodic ordered structure, the flow field itself evolves quite complex feature; especially in the vicinity of the tear. In the present study, the authors paid their special attention to this unique, complex flow field of O(1 mm) with deformable surface. The flow pattern and the spatio-temporal particle behavior in the tear were reconstructed by applying three-dimensional particle tracking velocimetry (3-D PTV). More >

A. Filali¹, L. Khezzar^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.3, pp. 307-329, 2013, DOI:10.3970/fdmp.2013.009.307

Abstract Numerical investigations of purely-elastic instabilities occurring in creeping flows are reported in planar cross-slot geometries with both sharp and round corners. The fluid is described by the upper-convected Maxwell model, and the governing equations are solved using the finite element technique based on a steady (non-iterative) direct solver implemented in the POLYFLOWcommercial software (version 14.0). Specifically, extensive simulations were carried out on different meshes, with and without the use of flow perturbations, for a wide range of rheological parameters. Such simulations show the onset of flow asymmetries above a critical Deborah number (De). The effect of rounding the corners is… More >

Lazhar Merouani¹, Belkacem Zeghmati², Azeddine Belhamri³

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.3, pp. 267-290, 2013, DOI:10.3970/fdmp.2013.009.267

Abstract The present work is a numerical study of laminar film condensation from vapor-gas mixtures in an inclined channel with an insulated upper wall and an isothermal lower wall coated with a thin porous material. A two-dimensional model is developed using a set of complete boundary layer equations for the liquid film and the steam-air mixture while the Darcy-Brinkman-Forchheimer approach is used for the porous material. The governing equations are discretized with an implicit finite difference scheme. The resulting systems of algebraic equations are numerically solved using Gauss and Thomas algorithms. The numerical results enable to determine the velocity, temperature and… More >

A.H. Ahadi¹, M.Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.4, pp. 397-422, 2012, DOI:10.3970/fdmp.2012.008.397

Abstract The numerical simulations of a thermodiffusion experiment in atmospheric pressure binary mixtures of water and isopropanol subject to micro-vibrations at reduced gravity are presented. The vibrations are induced on board ISS and FOTON-M3 due to many different reasons like crew activity, spacecraft docking or operating other experiments, etc. The effects of micro-gravity vibration were investigated in detail on all of the mixture properties. The influences of different cavity sizes as well as different signs of Soret coefficients in the solvent were considered. In this paper, the thermodiffusion experiment was subjected to two different g-jitter vibrations on board ISS and FOTON-M3… More >

Marcello Lappa^{1, 2}

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.1, pp. 1-20, 2005, DOI:10.3970/fdmp.2005.001.001

Abstract Possible natural transport mechanisms in cubical and shallow cavities with different heating conditions (from below or from the side) are investigated by means of numerical solution of the non-linear model equations and multiprocessor computations. Attention is focused on a variety of three-dimensional steady effects that can arise in such configurations in the case of low-Pr liquids (silicon melt) even for relatively small values of the temperature gradient due to localized boundary effects and/or true instabilities of the flow. Such aspects are still poorly known or completely ignored owing to the fact that most of the existing experiments focused on the… More >

Tiejun Wang¹, Tao Wu^1,*, Amir Homayoon Ashrafzadeh², Jia He¹

CMC-Computers, Materials & Continua, Vol.57, No.1, pp. 81-96, 2018, DOI:10.32604/cmc.2018.03259

Abstract Crowdsourcing is widely used in various fields to collect goods and services from large participants. Evaluating teaching quality by collecting feedback from experts or students after class is not only delayed but also not accurate. In this paper, we present a crowdsourcing-based framework to evaluate teaching quality in the classroom using a weighted average operator to aggregate information from students’ questionnaires described by linguistic 2-tuple terms. Then we define crowd grade based on similarity degree to distinguish contribution from different students and minimize the abnormal students’ impact on the evaluation. The crowd grade would be updated at the end of… More >

Xi Kan¹, Yonghong Zhang^2,*, Linglong Zhu², Liming Xiao², Jiangeng Wang³, Wei Tian⁴, Haowen Tan⁵

CMC-Computers, Materials & Continua, Vol.57, No.1, pp. 49-68, 2018, DOI:10.32604/cmc.2018.02376

Abstract Snow cover plays an important role in meteorological and hydrological researches. However, the accuracies of currently available snow cover products are significantly lower in mountainous areas than in plains, due to the serious snow/cloud confusion problem caused by high altitude and complex topography. Aiming at this problem, an improved snow cover mapping approach for mountainous areas was proposed and applied in Qinghai-Tibetan Plateau. In this work, a deep learning framework named Stacked Denoising Auto-Encoders (SDAE) was employed to fuse the MODIS multispectral images and various geographic datasets, which are then classified into three categories: Snow, cloud and snow-free land. Moreover,… More >