Hartmann number

About: Hartmann number is a research topic. Over the lifetime, 2593 publications have been published within this topic receiving 61342 citations.

Study of variable magnetic field and endoscope on peristaltic blood flow of particle-fluid suspension through an annulus

Abstract: In this article, the effects of variable magnetic field and endoscope on peristaltic motion of non-Newtonian blood flow of particle-fluid suspension through an annulus have been studied. The non-uniform annulus having incompressible, irrotational and electrically conducting fluid which is filled with rigid particles of different shapes. An assumption of long wavelength and zero Reynolds number approximation is applied to model the governing flow problem. A sinusoidal wave is traveling on the outer tube whereas the inner tube is considered as rigid and moving with a constant velocity. The expressions of velocity (u f , u p ) and pressure gradient have been obtained analytically and closed form solutions are presented. Numerical computation has been performed using symbolic computational software “Mathematica” to calculate the expressions for pressure rise and friction forces for outer and inner tube. The influence of all the physical parameters is discussed for pressure rise and friction forces. It is found that pressure rise increases due to the influence of magnetic field. It is also observed that friction forces for outer tube have greater magnitude as compared to friction forces for the inner tube. When the fluid depicts non- Newtonian behavior, then the pressure rise also diminishes. Moreover, the presence of particles in a fluid tends to resist the pressure. Higher values of Hartmann number diminish the friction forces significantly, however the friction forces for outer tube has greater magnitude as compared to inner tube. The present results are also presented for Newtonian fluid by taking λ 1 →0, as a special case of our study.

Application of dtm on mhd jeffery hamel problem with nanoparticle

Abstract: In this paper, the MHD Jeffery Hamel problem with nanoparticles for various values of Hartmann number has been investigated. The present study discusses about the velocity profile in the steady 2-dimensional flow of a MHD fluid with nanoparticles between two nonparallel walls. At first a similarity transformation is used to reduce the partial differential equations modeling the flow, to a single third-order nonlinear differential equation containing the semi angle between the plates, Reynolds number, the magnetic field strength and nanoparticle volume fraction as parameters. Differential Transformation method (DTM) has been used in order to study the problem and finally the obtained analytical results have been compared with numerical solutions and results achieved from pervious works in some numerical cases.

A numerical study of the effect of the magnetic field on turbulent fluid flow, heat transfer and entropy generation of hybrid nanofluid in a trapezoidal enclosure

Abstract: The purpose of this research is the numerical study of turbulent flow field, heat transfer and entropy generation of a Cuo-MWCNT-oil hybrid nanofluid in a trapezoidal enclosure under the influence of a magnetic field in natural convection. The enclosure side walls are insulated, the top wall is cold and the bottom one is hot. The study is done on Rayleigh numbers 107 to 1010, Hartmann numbers 0 to 500, and volume fractions 0 to 1 percent of nanoparticles. The governing equations were solved numerically using a finite volume method and SIMPLER algorithm. According to numerical results, it was observed that the application and increase of a magnetic field increases the flow tendency to vortices. In all Rayleigh numbers and for all the studied Hartmann numbers, the stream function and average Nusselt number reduced by increasing the volume fraction of nanoparticles. It was also observed that for smaller Rayleigh numbers, increasing the Hartmann number will have a more tangible effect on reducing the average Nusselt number. By increasing the Rayleigh number in all the studied Hartmann numbers and volume fractions, the total entropy generated increased. The optimal mode for each Rayleigh number in terms of the minimum value of entropy generation is the least volume fraction and the most Hartmann number.

Analytical investigation for Lorentz forces effect on nanofluid Marangoni boundary layer hydrothermal behavior using HAM

Abstract: In this paper, semi analytical approach is applied to investigate nanofluid Marangoni convection in presence of magnetic field. Koo–Kleinstreuer–Li model is taken into account to simulate nanofluid properties. Homotopy analysis method is utilized to solve the final ordinary equations which are obtained from similarity transformation. Roles of Hartmann number and nanofluid volume fraction are presented graphically. Results show that temperature augments with rise of nanofluid volume fraction. Impact of nanofluid volume fraction on normal velocity is more than tangential velocity. Temperature gradient enhances with rise of magnetic number.