The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Andrea Vacca - One of the best experts on this subject based on the ideXlab platform.
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torque reduction in taylor couette flows subject to an Axial Pressure Gradient
Journal of Fluid Mechanics, 2009Co-Authors: Marcello Manna, Andrea VaccaAbstract:The paper investigates the phenomena occurring in a Taylor-Couette flow system subject to a steady Axial Pressure Gradient in a small envelope of the Taylor-Reynolds state space under transitional regimes. A remarkable net power reduction necessary to simultaneously drive the two flows compared to that required to drive the Taylor-Couette flow alone is documented under non-trivial conditions. The energy transfer process characterizing the large-scale coherent structures is investigated by processing a set of statistically independent realizations obtained from direct numerical simulation. The analysis is conducted with an incompressible three-dimensional Navier-Stokes flow solver employing a spectral representation of the unknowns.
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Torque reduction in Taylor–Couette flows subject to an Axial Pressure Gradient
Journal of Fluid Mechanics, 2009Co-Authors: Marcello Manna, Andrea VaccaAbstract:The paper investigates the phenomena occurring in a Taylor-Couette flow system subject to a steady Axial Pressure Gradient in a small envelope of the Taylor-Reynolds state space under transitional regimes. A remarkable net power reduction necessary to simultaneously drive the two flows compared to that required to drive the Taylor-Couette flow alone is documented under non-trivial conditions. The energy transfer process characterizing the large-scale coherent structures is investigated by processing a set of statistically independent realizations obtained from direct numerical simulation. The analysis is conducted with an incompressible three-dimensional Navier-Stokes flow solver employing a spectral representation of the unknowns.
Marcello Manna - One of the best experts on this subject based on the ideXlab platform.
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torque reduction in taylor couette flows subject to an Axial Pressure Gradient
Journal of Fluid Mechanics, 2009Co-Authors: Marcello Manna, Andrea VaccaAbstract:The paper investigates the phenomena occurring in a Taylor-Couette flow system subject to a steady Axial Pressure Gradient in a small envelope of the Taylor-Reynolds state space under transitional regimes. A remarkable net power reduction necessary to simultaneously drive the two flows compared to that required to drive the Taylor-Couette flow alone is documented under non-trivial conditions. The energy transfer process characterizing the large-scale coherent structures is investigated by processing a set of statistically independent realizations obtained from direct numerical simulation. The analysis is conducted with an incompressible three-dimensional Navier-Stokes flow solver employing a spectral representation of the unknowns.
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Torque reduction in Taylor–Couette flows subject to an Axial Pressure Gradient
Journal of Fluid Mechanics, 2009Co-Authors: Marcello Manna, Andrea VaccaAbstract:The paper investigates the phenomena occurring in a Taylor-Couette flow system subject to a steady Axial Pressure Gradient in a small envelope of the Taylor-Reynolds state space under transitional regimes. A remarkable net power reduction necessary to simultaneously drive the two flows compared to that required to drive the Taylor-Couette flow alone is documented under non-trivial conditions. The energy transfer process characterizing the large-scale coherent structures is investigated by processing a set of statistically independent realizations obtained from direct numerical simulation. The analysis is conducted with an incompressible three-dimensional Navier-Stokes flow solver employing a spectral representation of the unknowns.
Tasawar Hayat - One of the best experts on this subject based on the ideXlab platform.
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Exact Solution for Peristaltic Transport of a Micropolar Fluid in a Channel with Convective Boundary Conditions and Heat Source/Sink
Zeitschrift für Naturforschung A, 2014Co-Authors: Tasawar Hayat, Humaira Yasmin, Bashir Ahmad, Guoqian ChenAbstract:This paper investigates the peristaltic transport of an incompressible micropolar fluid in an asymmetric channel with heat source/sink and convective boundary conditions. Mathematical formulation is completed in a wave frame of reference. Long wavelength and low Reynolds number approach is adopted. The solutions for velocity, microrotation component, Axial Pressure Gradient, temperature, stream function, and Pressure rise over a wavelength are obtained. Velocity and temperature distributions are analyzed for different parameters of interest
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Peristaltic flow of Johnson-Segalman fluid in asymmetric channel with convective boundary conditions
Applied Mathematics and Mechanics, 2014Co-Authors: Humaira Yasmin, Tasawar Hayat, A. Alsaedi, H. H. AlsulamiAbstract:This work is concerned with the peristaltic transport of the Johnson-Segalman fluid in an asymmetric channel with convective boundary conditions. The mathematical modeling is based upon the conservation laws of mass, linear momentum, and energy. The resulting equations are solved after long wavelength and low Reynolds number are used. The results for the Axial Pressure Gradient, velocity, and temperature profiles are obtained for small Weissenberg number. The expressions of the Pressure Gradient, velocity, and temperature are analyzed for various embedded parameters. Pumping and trapping phenomena are also explored.
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Peristaltic motion of Carreau fluid in a channel with convective boundary conditions
Applied Bionics and Biomechanics, 2014Co-Authors: Tasawar Hayat, Humaira Yasmin, A. AlsaediAbstract:We investigate the peristaltic motion of Carreau fluid in an asymmetric channel with convective boundary conditions. Mathematical formulation is first reduced in a wave frame of reference and then solutions are constructed by long wavelength and low Reynolds number conventions. Results of the stream function, Axial Pressure Gradient, temperature and Pressure rise over a wavelength are obtained for small Weissenberg number. Velocity and temperature distributions are analyzed for different parameters of interest. A comparative study between the results of Newtonian and Carreau fluids is given.
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effect of slip on peristaltic flow of powell eyring fluid in a symmetric channel
Applied Bionics and Biomechanics, 2014Co-Authors: Tasawar Hayat, Bashir Ahmad, Irfan S Shah, M MustafaAbstract:Peristaltic flow of non-Newtonian fluid in a symmetric channel with partial slip effect is examined. The non-Newtonian behavior of fluid is characterized by the constitutive equations of Powell-Eyring fluid. The motion is induced by a sinusoidal wave traveling along the flexible walls of channel. The flow is analyzed in a wave frame of reference moving with the velocity of wave. The equations governing the flow are solved by adopting lubrication approach. Series solutions for the stream function and Axial Pressure Gradient are obtained. Impact of slip and other emerging flow parameters is plotted and analyzed graphically.
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peristaltic motion of a carreau fluid in an asymmetric channel
Applied Mathematics and Computation, 2007Co-Authors: Tasawar HayatAbstract:Mathematical modeling and analytical solution are presented for the flow of an incompressible Carreau fluid in an asymmetric channel with sinusoidal wall variations. The peristaltic wave train on the channel walls has different amplitudes and phase. A long wavelength approximation is adopted to solve the flow problem. The explicit forms for the stream function, Axial Pressure Gradient and Pressure drop over a wavelength are obtained using a perturbation technique for a small Weissenberg number. The pumping characteristics, Axial Pressure Gradient and trapping phenomena has been mainly discussed. Comparison is made between the results for the Newtonian and Carreau fluids.
Kenneth G. Powell - One of the best experts on this subject based on the ideXlab platform.
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Similarity solutions for viscous vortex cores
Journal of Fluid Mechanics, 1992Co-Authors: Ernst W. Mayer, Kenneth G. PowellAbstract:Results are presented for a class of self-similar solutions of the steady, axisymmetric Navier-Stokes equations, representing the flows in slender (quasi-cylindrical) vortices. Effects of vortex strength, Axial Gradients and compressibility are studied. The presence of viscosity is shown to couple the parameters describing the core growth rate and the external flow field, and numerical solutions show that the presence of an Axial Pressure Gradient has a strong effect on the Axial flow in the core
Noreen Sher Akbar - One of the best experts on this subject based on the ideXlab platform.
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effects of temperature dependent viscosity on peristaltic flow of a jeffrey six constant fluid in a non uniform vertical tube
Communications in Nonlinear Science and Numerical Simulation, 2010Co-Authors: S Nadeem, Noreen Sher AkbarAbstract:Abstract This paper deals with the influence of heat transfer and temperature dependent viscosity on peristaltic flow of a Jeffrey-six constant fluid. The two-dimensional equations of Jeffrey-six constant fluid are simplified by making the assumptions of long wave length and low Reynolds number. The arising equations are solved for temperature, velocity profile and Axial Pressure Gradient using regular perturbation method and homotopy analysis method. The integration appeared in the Pressure rise is treated numerically to find the solution. The expressions for Pressure rise, temperature, Pressure Gradient and stream functions are sketched for various embedded parameters and interpreted. The graphical results are also presented for five different wave shapes.
