The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Tasawar Hayat - One of the best experts on this subject based on the ideXlab platform.
-
activation energy and chemical reaction in maxwell magneto nanoliquid with passive control of nanoparticle volume fraction
Journal of The Brazilian Society of Mechanical Sciences and Engineering, 2018Co-Authors: G K Ramesh, Tasawar Hayat, S. A. Shehzad, A. AlsaediAbstract:Two-Dimensional Flow of Maxwell magneto-nanoliquid by stretching surface is investigated. Convective boundary conditions and passive control of nanoparticles volume fraction are used for the analysis of thermal and concentration boundary layers. Flow analysis is created by considering Buongiorno model. Influences of activation energy and chemical reaction are useful application in lubrication practice, oil and water emulsions; therefore, we retained these effects. The differential framework is illustrated numerically via spectral relaxation method. Part of critical parameters on Flow fields and additionally on the skin fiction factor and energy and mass transportation rates are resolved and discussed.
-
impact of chemical reaction on third grade fluid Flow with cattaneo christov heat flux
Journal of Molecular Liquids, 2017Co-Authors: Maria Imtiaz, Ahmed Alsaedi, Anum Shafiq, Tasawar HayatAbstract:Abstract The present article deals with the Two-Dimensional Flow of third grade fluid induced by a linear stretching sheet. Analysis of thermal relaxation time is made by using Cattaneo-Christov heat flux model. Effects of chemical reaction are also taken into account. Suitable transformations lead to a strongly nonlinear differential system which is solved through homotopic technique. Convergent series solutions are derived. Effects of the emerging parameters on the dimensionless velocity, temperature and concentration are investigated. It is found that increasing values of thermal relaxation time corresponds to low temperature. Skin friction coefficient and Sherwood number are also computed and addressed.
-
influence of thermal radiation and joule heating on mhd Flow of a maxwell fluid in the presence of thermophoresis
International Journal of Heat and Mass Transfer, 2010Co-Authors: Tasawar Hayat, Muhammad QasimAbstract:This work investigates the magnetohydrodynamic (MHD) Two-Dimensional Flow with heat and mass transfer over a stretching sheet in the presence of Joule heating and thermophoresis. The resulting partial differential equations are converted into a set of coupled ordinary differential equations. Series solutions have been derived by using homotopy analysis method (HAM). The local Nusselt and Sherwood numbers are also computed. Graphical results for the dimensionless velocity, temperature and concentration fields are reported and examined for some parameters showing the interesting aspects of the obtained solutions.
-
three Dimensional Flow over a stretching surface in a viscoelastic fluid
Nonlinear Analysis-real World Applications, 2008Co-Authors: Tasawar Hayat, Muhammad Sajid, Ioan PopAbstract:This article looks at the hydrodynamic elastico-viscous fluid over a stretching surface. The equations governing the Flow are reduced to ordinary differential equations, which are analytically solved by applying an efficient technique namely the homotopy analysis method (HAM). The solutions for the velocity components are computed. The numerical values of wall skin friction coefficients are also tabulated. The present HAM solution is compared with the known exact solution for the Two-Dimensional Flow and an excellent agreement is found.
Ioan Pop - One of the best experts on this subject based on the ideXlab platform.
-
three Dimensional Flow over a stretching surface in a viscoelastic fluid
Nonlinear Analysis-real World Applications, 2008Co-Authors: Tasawar Hayat, Muhammad Sajid, Ioan PopAbstract:This article looks at the hydrodynamic elastico-viscous fluid over a stretching surface. The equations governing the Flow are reduced to ordinary differential equations, which are analytically solved by applying an efficient technique namely the homotopy analysis method (HAM). The solutions for the velocity components are computed. The numerical values of wall skin friction coefficients are also tabulated. The present HAM solution is compared with the known exact solution for the Two-Dimensional Flow and an excellent agreement is found.
Nicholas T Ouellette - One of the best experts on this subject based on the ideXlab platform.
-
correlating lagrangian structures with forcing in Two Dimensional Flow
Physics of Fluids, 2016Co-Authors: Charlie Hogg, Nicholas T Ouellette, Yang LiaoAbstract:Lagrangian coherent structures (LCSs) are the dominant transport barriers in unsteady, aperiodic Flows, and their role in organizing mixing and transport has been well documented. However, nearly all that is known about LCSs has been gleaned from passive observations: they are computed in a post-processing step after a Flow has been observed and used to understand why the mixing and transport proceeded as it did. In many applications, the ability instead to control the presence or location of LCSs via imposed forcing would be valuable. With this goal in mind, we study the relationship between LCSs and external forcing in an experimental quasi-Two-Dimensional weakly turbulent Flow. We find that the likelihood of finding a repelling LCS at a given location is positively correlated with the mean strain rate injected at that point and negatively correlated with the mean speed, and that it is not correlated with the vorticity. We also find that mean time between successive LCSs appearing at a fixed location is related to the structure of the forcing field. Finally, we demonstrate a surprising difference in our results between LCSs computed forward and backward in time, with forward-time (repelling) LCSs showing much more correlation with the forcing than backwards-time (attracting) LCSs.
-
long range ordering of turbulent stresses in Two Dimensional Flow
Physical Review E, 2015Co-Authors: Yang Liao, Nicholas T OuelletteAbstract:Using filter-space techniques, we study the spatial structure of the turbulent stress that couples motion on different length scales in a quasi-Two-Dimensional laboratory Flow. As the length scale increases, we observe the appearance of long-range, system-spanning spatial order of this stress, even though the Flow field remains disordered. Suggestively, this ordering occurs only in the range of scales over which we find net inverse energy transfer to larger scales. However, we find that a field built from wave vectors with random phases also displays ordering, suggesting that at least some of the ordering we observe is purely kinematic. Our results help to clarify the role played by geometric alignment in the turbulent energy cascade and highlight the importance of the scale-dependent rate of strain in the energy-transfer process.
-
mechanisms driving shape distortion in Two Dimensional Flow
EPL, 2011Co-Authors: A De Chaumont Quitry, Douglas H Kelley, Nicholas T OuelletteAbstract:In order to elucidate the physical processes governing the evolution of material areas in complex Flow, we study the shape dynamics of three-point Lagrangian clusters in an experimental quasi–Two-Dimensional Flow. By comparing our measurements with simulations of triangles evolving purely diffusively, we show that the path taken by the mean triangle shape through a suitably defined phase space is indicative of the underlying Flow dynamics. We demonstrate the existence of organizing curves in shape space for the evolution of triangles with different initial shapes. Our results suggest a detailed, multi-step process governing the shape dynamics of clusters in complex Flow.
F Durst - One of the best experts on this subject based on the ideXlab platform.
-
further contributions on the Two Dimensional Flow in a sudden expansion
Journal of Fluid Mechanics, 1997Co-Authors: N Alleborn, K Nandakumar, H Raszillier, F DurstAbstract:Two-Dimensional laminar Flow of an incompressible viscous fluid through a channel with a sudden expansion is investigated. A continuation method is applied to study the bifurcation structure of the discretized governing equations. The stability of the different solution branches is determined by an Arnoldi-based iterative method for calculating the most unstable eigenmodes of the linearized equations for the perturbation quantities. The bifurcation picture is extended by computing additional solution branches and bifurcation points. The behaviour of the critical eigenvalues in the neighbourhood of these bifurcation points is studied. Limiting cases for the geometrical and Flow parameters are considered and numerical results are compared with analytical solutions for these cases.
Y Shiotani - One of the best experts on this subject based on the ideXlab platform.
-
structural instability of the bifurcation diagram for Two Dimensional Flow in a channel with a sudden expansion
Journal of Fluid Mechanics, 2000Co-Authors: Jiro Mizushima, Y ShiotaniAbstract:Flow in a symmetric channel with a sudden expansion makes a transition from a symmetric Flow to an asymmetric one due to a symmetry-breaking pitchfork bifurcation on a gradual increase of the Reynolds number if the system is perfectly symmetric. However, an unavoidable infinitesimal imperfection of the system may render the pitchfork bifurcation imperfect. A weakly nonlinear stability analysis is proposed to investigate the structural instability of the bifurcation for such a Flow. As a result, an amplitude equation for a disturbance is derived by including the effect of the imperfection of the system, and its coefficients are evaluated numerically. The equilibrium amplitude of the disturbance is calculated from the amplitude equation and compared with the experimental results for the Flow in a channel that is presumed symmetric and also with the numerical solution of the full nonlinear equations for the Flow in a slightly asymmetric channel.
