The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Tasawar Hayat - One of the best experts on this subject based on the ideXlab platform.
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effect of homogeneous heterogeneous reactions in stagnation point flow of third grade fluid past a variable thickness stretching sheet
Neural Computing and Applications, 2018Co-Authors: Tasawar Hayat, Asmara Kiran, Maria Imtiaz, Ahmed AlsaediAbstract:Present work addresses the stagnation point flow of third grade fluid past a variable thicked stretching sheet. Homogeneous and heterogeneous reactions are considered. Impact of thermal radiation and variable wall temperature is studied here. System of nonlinear ordinary differential equations is obtained by suitable transformations. Convergence of series solutions is achieved. Fluid flow, temperature and Concentration Field are deliberated through graphs for different parameters. It is seen that velocity and temperature Fields increase for higher shape parameter. Increasing values of homogeneous parameter decline the Concentration profile. Velocity profile enhances when wall thickness parameter and ratio of free stream velocity and stretching velocity are increased.
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soret and dufour effects in three dimensional flow over an exponentially stretching surface with porous medium chemical reaction and heat source sink
International Journal of Numerical Methods for Heat & Fluid Flow, 2015Co-Authors: Tasawar Hayat, S A Shehzad, Taseer Muhammad, A AlsaediAbstract:Purpose – The purpose of this paper is to study the Soret and Dufour effects in three-dimensional flow induced by an exponential stretching surface in a porous medium. Design/methodology/approach – Series solutions are developed. Findings – The authors observed that the temperature profile and thermal boundary layer thickness are enhanced when the authors increase the values of Dufour number. It is also examined that the Concentration Field and its associated boundary layer thickness are higher for the larger values of Soret number. Originality/value – Such investigation is not available in the literature.
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thermophoresis particle deposition in mixed convection three dimensional radiative flow of an oldroyd b fluid
Journal of The Taiwan Institute of Chemical Engineers, 2014Co-Authors: S A Shehzad, A Alsaedi, Tasawar Hayat, M S AlhuthaliAbstract:Abstract This article describes heat and mass transfer characteristics in three-dimensional flow of an Oldroyd-B fluid. The flow caused is due to bidirectional stretching surface. Radiation effects are taken into account via Rosseland approximation. In addition the thermophoresis effects are considered. Results of velocities, temperature and Concentration are constructed. The obtained results are plotted and discussed for interesting physical parameters. We have seen that the increasing values of thermophoretic parameter leads to a decrease in the Concentration Field and Concentration boundary layer thickness. Also it is noticed that the Concentration Field corresponding to thermophoretic parameter decays quickly in comparison to Concentration Field for Schmidt number.
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influence of compliant walls on peristaltic motion with heat mass transfer and chemical reaction
International Journal of Heat and Mass Transfer, 2012Co-Authors: S Hina, Tasawar Hayat, S Asghar, Awatif A HendiAbstract:Abstract In this work the fundamental problem of peristalsis with heat and mass transfer is investigated in the presence of a chemical reaction. An incompressible viscous fluid is considered in a channel with compliant walls. Mathematical modeling is based upon the laws of mass, linear momentum, energy and Concentration. Analysis is presented not only for long wavelength and low Reynolds number but also for small Grashof number. The solutions are carried out for the stream function, temperature, Concentration Field and heat transfer coefficient. The results of various interesting parameters are plotted and discussed.
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effects of heat and mass transfer on the peristaltic flow of hyperbolic tangent fluid in an annulus
International Journal of Heat and Mass Transfer, 2011Co-Authors: Noreen Sher Akbar, Tasawar Hayat, S Nadeem, Awatif A HendiAbstract:This article deals with the influence of heat and mass transfer on peristaltic flow of a hyperbolic tangent fluid in an annulus. The two dimensional equations of tangent hyperbolic fluid are simplified by making the assumptions of long wave length and low Reynolds number. Exact solutions are evaluated for both heat and Concentration Field, while analytical and numerical solutions are carried out for velocity profile. Comparison of both the solution is presented through graph and table. The expressions for pressure rise, temperature, Concentration Field and pressure gradient are sketched for various embedded parameters and interpreted.
Erich J Plate - One of the best experts on this subject based on the ideXlab platform.
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wind tunnel study of Concentration Fields in street canyons
Atmospheric Environment, 1999Co-Authors: Petra Kastnerklein, Erich J PlateAbstract:Abstract The paper presents results from a case study of gaseous pollutant dispersion in street canyons. Tracer-gas experiments were performed in a neutrally stratified wind tunnel. Vehicle emissions were simulated as line sources. Concentration profiles along building walls were measured. A two-dimensional street canyon was considered as the reference case. The influence of systematic parameter variations on the Concentration Field is studied and discussed. Building dimensions, upwind building configuration, wind direction and roof geometry were found to be important parameters. Data sets from the study may be used for evaluation of numerical models and for expert estimates of air quality in the urban environment
A Abdul K Hakeem - One of the best experts on this subject based on the ideXlab platform.
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velocity slip effects on heat and mass fluxes of mhd viscous ohmic dissipative flow over a stretching sheet with thermal radiation
Ain Shams Engineering Journal, 2016Co-Authors: M Kayalvizhi, R Kalaivanan, Vishnu N Ganesh, B Ganga, A Abdul K HakeemAbstract:Abstract In the present article, we discussed the velocity slip effects on the heat and mass fluxes of a viscous electrically conducting fluid flow over a stretching sheet in the presence of viscous dissipation, Ohmic dissipation and thermal radiation. A system of governing nonlinear PDEs is converted into a set of nonlinear ODEs by suitable similarity transformations. The numerical and analytical solutions are presented for the governing non-dimensional ODEs using shooting method and hypergeometric function respectively. The results are discussed for skin friction coefficient, Concentration Field, non-dimensional wall temperature and non-dimensional wall Concentration. The non-dimensional wall Concentration increases with slip and magnetic parameters and decreases with Schmidt number. Furthermore, comparisons are found to be good with bench mark solutions.
Paul J. Sullivan - One of the best experts on this subject based on the ideXlab platform.
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mean square values of Concentration in a contaminant cloud
Environmetrics, 1995Co-Authors: F Labropulu, Paul J. SullivanAbstract:A simple and relatively general analytic expression for the distributed second central moments of scalar Concentration is derived. The ‘fluctuations’ or mean-square values are given in terms of the mean Concentration Field and apply in either an inertial or cloud centre-of-mass reference frame. Clouds in homogeneous grid turbulence, in the neutral atmospheric boundary layer, and in the inertial sub-range are used as illustrative examples.
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a simple representation of a developing contaminant Concentration Field
Journal of Fluid Mechanics, 1995Co-Authors: Brian L. Sawford, Paul J. SullivanAbstract:Chatwin & Sullivan have demonstrated that, for a wide range of self-similar scalar Fields, the moments of the probability density function of Concentration have a very simple form. Here, an extension to this simple form which takes account of the source distribution is developed. This extension has two effects. Firstly it modifies the values of the two parameters appearing in the original theory and in particular explains the observed behaviour of these parameters very near to a line source of heat in grid turbulence. Secondly, it introduces an additional parameter in the description of each moment beyond the second. It is shown that these additional parameters are necessary in order to describe measurements of the first four central moments throughout the Concentration Field from a continuous line source of heat in grid-generated turbulence
B Ruck - One of the best experts on this subject based on the ideXlab platform.
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influence of trees on the dispersion of pollutants in an urban street canyon experimental investigation of the flow and Concentration Field
Atmospheric Environment, 2007Co-Authors: C Christof B Gromke, B RuckAbstract:Flow Field and Concentration measurements have been performed in an idealized model of an urban street canyon with one row of trees arranged along the center axis. The model was set up in an atmospheric boundary layer wind tunnel and the approach flow was directed perpendicular to the street axis. A line source embedded in the bottom of the street was used to release tracer gas for the simulation of traffic exhaust emissions. Trees with spherical crowns were modeled and positioned inside the street canyon, varying crown diameter, crown permeability, trunk height and tree spacing. Traffic-induced turbulence was simulated by rotating belts with thin plates. Concentrations were measured at the facades of the street canyon. For small tree crowns, only little changes in Concentration were measured, however, increasing crown diameters led to increasing Concentrations at the leeward street canyon wall associated with a reduction of local Concentrations at the windward wall. For some cases, a variation of trunk height led to a modification of the Concentration pattern on the walls. Increasing the tree spacing resulted in a noticeable Concentration decrease. When compared to the situation with standing (but emitting) traffic, the traffic-induced turbulence by two-way car movements always contributed to a more homogenous Concentration Field inside the street canyon yielding to reduced mean Concentration levels.