Effect Of Radial Magnetic Field Research Articles

Research on Magnetic-Induced Error of Small-Sized Fiber Optic Gyro Fiber Coil in Space Environment

Spacecraft is severely limited in weight and volume, resulting in a small bending radius of the fiber coil used by IFOG (Interference Fiber Optic Gyroscope). The fiber coil has such a size that the influence of bending on fiber birefringence cannot be ignored. In this paper, we research magnetic-induced errors of small-sized IFOG working in low orbit space. Firstly, we use the Jones matrix to analyze the effects of radial magnetic field and axial magnetic field on IFOG. Secondly, we establish a three-dimensional model for the radial magnetic-induced errors and magnetic-induced errors of minor radius fiber coil. Using the finite element method, we analyze the magnetic-induced error between different levels of the fiber coil. Combined with the birefringence distribution of the minor radius fiber coil, an accurate three-dimensional magnetic-induced error model is established. Thirdly, in the experiment, we design the magnetic-induced error test platform that includes the Fluke standard current source, transconductance amplifier, and Helmholtz coil. The experimental results show that, compared with the traditional calculation method, the three-dimensional magnetic-induced error model reduces the RMSE (Root Mean Square Error) of the radial magnetic field by 56.9% and the RMSE of the axial magnetic field by 35.7%, respectively.

Exergy and energy analysis on ciliated rheology of viscoelastic liquid in a curved pump with porous saturated space: a blood propelling application

ABSTRACT In the current analysis, the rheology of non-Newtonian liquid in a curved pump (CP) is considered. The Jeffrey fluid is used as blood (non-Newtonian liquid) in this investigation. The transportation of fluid takes place due to the metachronal wavy structure of the boundary wall. The combined effects of radial magnetic field and porous medium on flow features are also taken into account. Additionally, mathematical modeling related to avoidable and unavoidable exergy is also used. The physical effects of involved parameters are studied via graphs. The parabolic pattern is noticed in the velocity profile for both viscous fluid (NF) and viscoelastic fluid (when viscoelastic parameter has a small strength), while sharp changes (boundary layer, BL) are noticed near both boundaries under a larger strength of the viscoelastic parameter. The CP has a larger pressure gradient and heat transfer rate as associated with the straight pump (SP). The viscous fluid has a larger heat transfer rate at the upper wall (HTRUW) as associated with the viscoelastic fluid. The CP has a larger entropy generation as associated with the SP. The magnetic and porosity parameters have a vibrant role in augmenting the magnitude of both entropy generation and average entropy generation. The viscoelastic parameter has a remarkable role in enhancing the magnitude of Bejan number as compared with the viscous parameter.

Numerical study of the effect of radial magnetic field on performance of Hall thruster

The Hall-effect thruster has wide applications for commercial aerospace because of the high thrust density and simple structure. In order to further improve the performance of low-power Hall thruster and to solve the problem that the performance of low-power Hall thruster for low-orbit satellites is limited by the input power and maximum magnetic field intensity, the influence of radial magnetic field distribution in the discharge channel on the performance of the thruster is studied by numerical simulation and theoretical analysis in this work through changing the radial magnetic gradient on condition that the axial magnetic profile and the magnetic strength remain unchanged. The results show that the potential of the acceleration zone decreases with the increase of radial distance when the discharge parameters, propellant flow rate and axial magnetic field are unchanged. Therefore, the greater the radial magnetic field gradient near the inner wall of the thruster discharge channel, the greater the kinetic energy of the ions drifting along the axial direction to the thruster outlet, , and the greater the thrust of thruster. The research results of this work provide theoretical support for the magnetic field design and performance optimization of hall thrusters.

Role of Suction/Injection on Natural Convection Flow of Magnetite $$ ({\text{Fe}}_{ 3} {\text{O}}_{ 4} ) $$ Nanoparticles in Vertical Porous Micro-annulus Between Two Concentric Tubes: A Purely Analytical Approach

Natural convection heat transfer analysis was carried out to examine the flow of magnetite–water ferrofluid in an annular zone between a pair of vertical micro-cylindrical tubes under conditions of slip velocity and thermal jump at the porous wall of cylinders. The effects of radial magnetic field and thermal radiation are also considered along with suction/injection at the walls. Linear Rosseland approximation was employed to obtain the expression for thermal radiation. Similarity variables and non-dimensional parameters are introduced to express the resultant flow equations in term of continuity, momentum and energy in a dimensionless fashion. A closed-form solution of the problem was constructed in the form of modified Bessel functions of the first and second kind. The numerical values of the obtained expressions for fluid velocity, temperature profiles, volume flow rate, surface friction and Nusselt number were plotted to examine the significance of different flow parameters. It was found that the fluid velocity was reduced when injection parameter was increased, while it was augmented when the suction parameter was increased. In contrast to this, opposite effects were observed in the temperature distribution. Further, the suction parameter enhances the rate of heat transfer at the inner surface of outer porous cylinder, while the injection parameter has a decreasing effect on the same.

Effect of radial magnetic field on the natural convection in a semi-circular curved enclosure for different aspect ratios

The problem of natural convection in a (2D) semi-circular curved enclosure in the presence of a radial magnetic field is numerically studied in this paper. The selected configuration is such that the convective flow is driven by a mean temperature gradient also directed radially, and the effects of enclosure aspect ratio and the strength of the applied magnetic field are considered. Numerical simulations are carried out using a (3D) MHD code developed by our research group, first at a fixed \(Ra = 10^5 \) and \(Pr = 0.71\) for aspect ratios \(A = 2, 4, 6, 8\) and Hartmann numbers in the range \(Ha = 0-100\). As the aspect ratio is increased, a Rayleigh–Bénard-like convection with the convective cells formed near the symmetric central portion of the enclosure, where the mean temperature gradient is anti-parallel to the gravity, is found to be triggered. Except at the transition, the effect of the imposed radial magnetic field is found to decrease the fluid motion in general, and the convective motion is completely suppressed at \(Ha = 100\) irrespective of the aspect ratio. The critical Hartmann number for the onset of (R–B-like) convection is found to decrease with an increase in the aspect ratio. Numerical simulations are also attempted at a fixed \(A = 10\) and \(Ra = 8000\) for Prandtl numbers \(Pr = 10, 0.1, 0.01\) and Hartmann numbers \(Ha = 0,3,6,9,12\). In the absence of the applied magnetic field, the flow is found to exhibit periodic oscillations of increased amplitude and time-period when Pr is decreased, except at \(Pr = 10\), where a steady-state solution is found. For \(Pr = 0.01\), the oscillatory flow is observed to persist even when the magnetic field strength is increased in the range \(Ha = 3 - 12\). Moreover, the temporal frequency of these flow oscillations is found to be nearly the same for \(Ha \le 9\).

Entropy generation under the influence of radial magnetic field and viscous dissipation of generalized Couette flow in an annulus

This paper investigates the combined effect of radial magnetic field and viscous dissipation on entropy generation in horizontal co-axial cylinders of generalized Couette flow. The analytical solutions for velocity and temperature profiles are obtained and utilized to compute the entropy generation, Bejan number as well as the average entropy generation number. The effect of relevant parameters on temperature field, velocity field, entropy generation, average entropy and Bejan number are portrayed graphically and discussed. We observed that heat transfer irreversibility dominates irreversibility for both isothermal and isoflux heating near the inner surface of the fixed outer cylinder with higher dominance in the case of isoflux heating. The reverse is seen on the moving inner cylinder.

Numerical investigations on magnetic field modeling for Carreau non-Newtonian fluid flow past an isothermal sphere

In the current study, the effects of radial magnetic field, slip and jump conditions on the steady two-dimensional free convective boundary layer flow over an external surface of an isothermal sphere for an electro-conductive polymer are numerically studied. It is assumed that the studied fluid has a non-Newtonian rheological behavior and follows the Carreau fluid model. In this investigation, the formulation of the Carreau fluid model has been used first time for describing the present boundary layer problem, and then the resulting partial differential equations are transformed to ordinary differential equations by using non-similarity transformations. The obtained ordinary differential equations are solved numerically by a well-known method named as Keller-Box method. The finding results show that a weak elevation in temperature is accompanied with the increase in the Carreau fluid parameter, whereas a significant acceleration in the flow is computed near the sphere surface. It is shown also that an increase in the thermal slip parameter allows to strongly decrease both the skin friction coefficient and the local Nusselt number. The skin friction coefficient is also depressed with increasing magnetic body force parameter. Moreover, it is observed that an increase in the momentum slip parameter allows to decrease the skin friction coefficient, whereas the local Nusselt number is reduced with the increase in the Carreau fluid parameter. It is found also that the skin friction coefficient is increased with greater stream-wise coordinate, whereas the local Nusselt number is reduced with the increase in this parameter.

Effect of radial magnetic field on peristaltic transport of Jeffrey fluid in curved channel with heat / mass transfer

In this paper, we deals with the impact of radialiy magnetic field on the peristaltic transport of Jeffrey fluid through a curved channel with two dimensional. The effect of slip condition on velocity, the non-slip condition on temperature and conversation is performed. The heat and mass transfer are considered under the influence of various parameters. The flow is investigated under the assumption of long wave length and low Reynolds number approximations. The distribution of temperature and concentration are discussed for various parameters governing the flow with the simultaneous effects of Brinkman number, Soret number and Schmidt number.

Effect of Radial Magnetic Field on Free Convective Flow over Ramped Velocity Moving Vertical Cylinder with Ramped Type Temperature and Concentration

Effect of Radial Magnetic Field on Free Convective Flow over Ramped Velocity Moving Vertical Cylinder with Ramped Type Temperature and Concentration

Influence of variable viscosity and radial magnetic field on peristalsis of copper-water nanomaterial in a non-uniform porous medium

Paramount idea of this article is to model peristaltic flow of copper-water for spherical and cylindrical shape magneto-nanoparticles in a curved channel. The nanomaterial saturates a non-uniform permeable medium in which the porosity of the medium fluctuate with the distance from the channel boundaries. H–C model is considered to predict the effective thermal conductivity of the nanomaterial. Effects of radial magnetic field, variable viscosity and mixed convection are also accounted. The boundary conditions yield the second order velocity and thermal slip effects. Assumptions of small Reynolds number and large wavelength approximation are utilized to simplify the governing equations. Final form of the system of equations are solved numerically through NDSolved command in Mathematica 8 software. Influence of embedded parameters on velocity, temperature and heat transfer rate of the nanomaterial at upper wall of the channel are physically interpreted. Comparison between the spherical and cylindrical shapes magneto-nanoparticles is also presented. Graphical results shows that pressure gradient and pressure rise are enhanced for both radial magnetic field parameter and nanoparticle volume fraction. Velocity of the nanomaterial increases when variable viscosity parameter is enhanced.

Effect of radial magnetic field on natural convection flow in alternate conducting vertical concentric annuli with ramped temperature

In this article, a numerical analysis has been performed to study the effect of radial magnetic field on natural convection of a viscous incompressible and electrically conducting fluid within the concentric vertical annuli containing a ramped type temperature profile at the surface of inner cylinder taking into account the induced magnetic field. Two cases are considered which are case 1, when inner cylinder is perfectly conducting and outer cylinder is non-conducting and case 2, has opposite configuration. The governing partial differential equations have been solved by using Matlab software. The influence of Hartmann number and magnetic Prandtl number on different profiles has been presented graphically. It is found that the effect of Hartmann number and magnetic Prandtl number is to decrease the velocity profile in both the cases. This study suggest that the heat transfer can be controlled by using ramped temperature and conductivity of the cylinder.

Joule heating and thermal radiation effects on peristalsis in curved configuration

The present paper looks at the effect of radial magnetic field on peristalsis of Sutterby fluid in a curved channel with velocity and temperature slip conditions. The channel walls satisfy the complaint properties. The energy equation is modeled by Joule heating, thermal radiation and viscous dissipation. The nonlinear differential equations for velocity and temperature have been numerically solved under the long wavelength and low Reynolds number approximations. Further the graphical results of axial velocity and temperature for various values of sundry parameters are discussed. It is observed that Hartman number has similar effect on the velocity and temperature profiles. The symmetric nature of velocity is observed for larger values of curvature parameter.

Simultaneous effects of radial magnetic field and wall properties on peristaltic flow of Carreau-Yasuda fluid in curved flow configuration

The objective of present article is to address the magnetohydrodynamic (MHD) peristaltic flow of Carreau-Yasuda fluid in a curved geometry. The channel boundaries satisfy wall slip and compliant properties. The fluid is electrically conducting through an applied magnetic field in the radial direction. Heat transfer is also studied. Governing equation comprised the viscous dissipation effects. The non-linear expressions are first obtained and then approximated using long wavelength and low Reynolds number considerations. The resulting systems are solved for the series solutions. The expressions of velocity, temperature, heat transfer coefficient and stream function are obtained and analyzed via graphical illustrations.

Solar cycle variations of magnetopause locations

The magnetopause location is generally believed to be determined by the solar wind dynamic pressure and by the sign and value of the interplanetary magnetic field vertical (BZ) component. The contribution of other parameters is usually considered to be minor or negligible near the equatorial plane. Recent papers have shown a magnetopause expansion during intervals of a nearly radial IMF but our ability to predict the magnetopause location under steady or slowly changing upstream conditions remains rather weak even if the effect of radial magnetic field is considered. We present a statistical study based on more than 10,000 magnetopause crossings identified in the THEMIS data in the course of the last half of the solar cycle. The observed magnetopause locations are compared with an empirical magnetopause model of Shue et al. (1997) and the sources of differences between observations and model predictions are analyzed. This analysis reveals that the magnetopause location depends on the solar activity being more compressed during the solar maximum. Furthermore, we have found that, beside the solar wind dynamic pressure and vertical magnetic field component, the solar wind speed and ionospheric conductivity (F10.7 used as a proxy) are important physical quantities controlling this compression.

Effect of Radial Magnetic Field and Temperature Gradient on Separation of Components of a Binary Fluid Mixture Confined in an Annular Region

The effect of a radial magnetic field on separation of a binary mixture of incompressible viscous thermally and electrically conducting fluids confined between two concentric cylinders in which the inner is rotating with a uniform angular velocity and having a uniform suction of the mixture with a constant velocity and outer is at rest. The equations governing the motion, temperature and concentration in cylindrical polar co-ordinate are solved analytically. The solution obtained in closed form for concentration distribution is plotted against the radial distances from the surface of the inner cylinder for various values of non-dimensional parameters viz. The Hartmann number, thermal diffusion number, baro diffusion number, suction Reynolds number, the product of Pradtl number and Eckert number, the product of Schmidt number and suction Reynolds number and the suction parameters affects the species separation of rarer and lighter component significantly.

Effect of Radial Magnetic Field on Flow of Blood in a Catheterized Tapered Artery with Mild Stenosis

Effect of Radial Magnetic Field on Flow of Blood in a Catheterized Tapered Artery with Mild Stenosis

Persistent Current in a Mesoscopic Cylinder: Effects of Radial Magnetic Field

In this work, we study persistent current in a mesoscopic cylinder subjected to both longitudinal and transverse magnetic fluxes. A simple tight-binding model is used to describe the system, where all the calculations are performed exactly within the non-interacting electron picture. The current $I$ is investigated numerically concerning its dependence on total number of electrons $N_e$, system size $N$, longitudinal magnetic flux $\phi_l$ and transverse magnetic flux $\phi_t$. Quite interestingly we observe that typical current amplitude oscillates as a function of the transverse magnetic flux, associated with the energy-flux characteristics, showing $N \phi_0$ flux-quantum periodicity, where $N$ and $\phi_0$ $(=ch/e)$ correspond to the system size and the elementary flux-quantum respectively. This analysis may provide a new aspect of persistent current for multi-channel cylindrical systems in the presence of radial magnetic field $B_r$, associated with the flux $\phi_t$.

Geometrical factors affecting magnetic properties of wound toroidal cores

Although toroidal cores wound from grain-oriented silicon iron strip are basically simple devices used in many applications, their magnetic properties are known to vary in a complex manner with core dimensions. The theoretical effects of radial magnetic field and flux density variation, interlamina normal flux, and winding stress on the real and apparent power loss and the permeability of a range of toroids with typical commercial dimensions are discussed. Comparisons are made with actual performance. It is shown that the radial variation of flux densities has a very small effect on the power loss and permeability but the interlamina normal flux has an influential effect, particularly in small-diameter toroids. It is shown that to obtain low losses and magnetizing currents, toroids should be designed using wide strips having large internal diameter and low buildup. >

Hydromagnetic convective heat transfer in vertical pipes

In the present analysis, we consider the effect of radial magnetic field on the steady flow produced by the combined free and forced convection in an annulus between two coaxial vertical cylinders. A numerical solution of the problem is obtained by using Runge-Kutta-Merson method. For Rayleigh number Ra 0, there occurs back flow controlled by the effect of the magnetic field. Further, the influence of Rayleigh number and Hartmann number on the temperature is also discussed.