Electromagnetic Pump Research Articles

Neutron radiography of particle-laden liquid metal flow driven by an electromagnetic induction pump

Neutron radiography of particle-laden liquid metal flow driven by an electromagnetic induction pump

Thermal, microrotation, electromagnetic field and nanoparticle shape effects on Cu-CuO/blood flow in microvascular vessels

A thermal analysis of Cu-CuO/ blood nanofluids flow in asymmetric microchannel propagating with wave velocity is presented in this study. For the blood, a micropolar fluid model is considered to investigate the microrotation effects of blood flow. Thermal radiation effects and the influence of nanoparticle shape, electric double layer thickness, and electromagnetic fields on the flow are studied. Three types of nanoparticles shapes namely cylinder, bricks and platelets are taken into account. Governing equations are solved under the approximations of long wavelength, low Reynolds number, and Debye-Hückel linearization. Numerical computations are performed for the axial pressure gradient, axial velocity, spin velocity and temperature distribution. The effects of various physical parameters on flow and thermal characteristics are computed and their physical interpretation is also discussed. The outcomes indicate that the axial velocity of Cu-CuO/blood nanoparticles strongly depends on applied electromagnetic field and microrotation. The model's finding will be applicable in designing the smart electromagnetic micro pumps for the hemodialysis and lungs-on-chip devices for the pumping of the blood.

A novel layered stack electromagnetic pump towards circulating metal fluid: Design, fabrication and test

In this paper, a novel structure of electromagnetic pump to efficiently drive metal fluid was proposed, which can be called layered stack electromagnetic pump. Firstly, the coupled interaction mechanism of multi-physics fields was numerically interpreted, and the parameter optimizations of DC-EMP were systemically conducted. The optimization results show that inserting insulation bars can significantly reduce current dissipation by 69.7% in center line. And using closed iron yoke is beneficial to obtain a strong and uniform magnetic field. Moreover, the low flow duct is good to obtain a large pressure head. Based on the optimization results, a five layer structure of flow duct was provided. And a prototype was fabricated and tested. It shows that such pump can provide pressure head 120 kPa @ 300 A and maximum flow rate 6.9 L/min @300 A. It works smoothly and silently, and even, can operate steadily after two year intermittent operation. And this pump operation temperature was limited below 120 °C. Finally, the challenges unsolved and further optimization measures were suggested. Overall, the layered stack DC-EMP presented here enables liquid metal to be rather promising heat transfer fluid in advancing the field of extreme heat flux heat dissipation and thermal energy transportation.

Theoretical exploration of thermal transportation with chemical reactions for sutterby fluid model obeying peristaltic mechanism

In the field of engineering, Biologically-inspired propulsion systems are getting the utmost importance. The theoretical analysis explores the effect of heterogeneous-homogeneous reactions on heat and thermal transfer analysis for incompressible Sutterby fluid. Using low Reynolds number and long wavelength assumptions, the governing system of equations of fluid transport problem is abridged and solved using the perturbation technique. The Nusselt number and skin friction coefficient are also incorporated in this contemplation. Particular attention is given to elastic parameters and Brinkman number and plotted their graph for velocity profile, temperature distribution, and concentration profile. It is initiated that momentum distribution profile is enhanced for higher values of elastic parameters, which is because less resistance occurs at the channel walls. The impact of heterogeneous and homogeneous reactions shows reverse bearing on the concentration field. Brinkman number (viscous dissipation effects) contributes to boosts the thermal profile for all the cases. Moreover, augmentation in skin friction is noticed by escalating the parametric values of damping and rigidity. The present study has a wide range of applications in biomedical engineering and biological functions i.e. electromagnetic peristaltic micro pumps.

Exploratory fire analysis in DONES lithium system

The exploitation of Nuclear Fusion energy in power plants will require the development and qualification of materials able to withstand outstanding neutronic loads for which no operating experience is currently available. Therefore, a Demo-Oriented early NEutron Source (DONES) facility for material irradiation is currently being designed within EUROfusion programme aimed at the production of neutrons with fusion relevant spectrum and fluence by means of D – Li stripping reactions occurring between a deuteron beam impacting a stable liquid lithium flowing film implementing the target. The Lithium System (LS) in DONES shall provide circulation of liquid lithium with suitable thermal-hydraulic characteristics and assure impurity control and heat removal. Given the hazard constituted by liquid lithium inventory and the potential risk of reactions with air eventually resulting into fire events, a preliminary evaluation of the modality of occurrence and evolution of such abnormal events in LS has been performed. In particular, two events have been selected for fire analysis. The first event considers a failure of off-line sampler equipment with water getting in contact with sampled lithium inventory. The initiating event is a failure in the glove box containing the off-line sampler. An air ingress occurs in the glovebox and a break of the Li flask is hypothesized at the same time. The second event assumes a leak at the outlet of the electromagnetic pump with loss of Lithium from the Li pipe in Heat Rejection System in LS room. Simultaneous air ingress is hypothesized as well in LS room (normally filled with inert argon). Fire loads were initially identified for the selected events and the room models developed considering dimensions, lithium inventory and fire compartment assumed to coincide with room limits. The ignition of lithium in contact with air occurs at liquid lithium operating temperature as reported in most conservative observations in literature and lithium fires were simulated as heat flux associated to lithium – air reactions rates observed in literature. A model for both events was implemented in Fire Dynamic Simulator (FDS) code to evaluate fire dynamics and a sensitivity analysis was performed on relevant inventories in the lithium loop area to investigate possible consequences.

Modeling and experimental study on a novel linear electromagnetic collaborative rectification pump

A novel linear electromagnetic collaborative rectification pump (LCP) consisting of two linear electromagnetic drive oscillating pump units (LPUs) is presented in this paper. It is capable of producing high stroke by utilizing linear motor. Moreover, its novel collaborative rectification structure differs from check valve and active valve rectification measures used in conventional hybrid hydraulic pumps driven by smart materials. A mechanical linkage of piston and rectification valve's spool is designed along with coordination of two LPUs achieves the rectification of in-and-out flow at chambers’ ports. Collaborative rectification brings hydraulic coupling effect between two LPUs, which is analyzed in-depth. Moreover, the dynamic model consisting of motor, cylinder and valve is formulated analytically. Following that, a two-units decoupling method with mutual compensation is proposed to achieve synchronous and out-of-phase motions of the pistons. A research prototype of LCP along with test platform has been developed. Experiments are conducted on the output performance of the system. The result shows that the two-units decoupling method can improve the coordination of the two LPUs and the volumetric efficiency of the system significantly. The volumetric efficiency in different load condition and the bandwidth of LCP are got. A positive correlation between LCP bandwidth and the oscillating frequency of the linear motor are revealed.

Electron heating by HF pumping of high-latitude ionospheric F-region plasma near magnetic zenith

Abstract. High-frequency electromagnetic pumping of ionospheric F-region plasma at high and mid latitudes gives the strongest plasma response in magnetic zenith, antiparallel to the geomagnetic field in the Northern Hemisphere. This has been observed in optical emissions from the pumped plasma turbulence, electron temperature enhancements, filamentary magnetic field-aligned plasma density irregularities, and in self-focusing of the pump beam in magnetic zenith. We present results of EISCAT (European Incoherent SCATter association) Heating-induced magnetic-zenith effects observed with the EISCAT UHF incoherent scatter radar. With heating transmitting a left-handed circularly polarized pump beam towards magnetic zenith, the UHF radar was scanned in elevation in steps of 1.0 and 1.5∘ around magnetic zenith. The electron energy equation was integrated to model the electron temperature and associated electron heating rate and optimized to fit the plasma parameter values measured with the radar. The experimental and modelling results are consistent with pump wave propagation in the L mode in magnetic zenith, rather than in the O mode.

Parametric excitation surface waves at plasma boundary under action of p-polarized laser radiation

The parametric excitation of surface waves at the plasma boundary under the action of a p-polarized electromagnetic pump wave is analyzed. The instability, at which the pump wave decays into two surface electromagnetic TM modes, is considered. The dependence of the instability growth rate on the plasma electron density, the angle of incidence of the pump wave, and the direction of propagation of the excited surface waves is investigated. It is shown that the instability growth rate has a maximum value in the case when short-wave quasistatic surface waves are excited.

Real-time gas cooling of flowing liquid lithium limiter for the EAST

Abstract A novel continuously flowing liquid lithium limiter (FLiLi) which employs an in-vessel electro-magnetic pump to drive liquid Li flowing on the surface of limiter has been successfully designed and tested in the experimental advanced superconducting tokamak (EAST) device in 2014. In order to better control the surface temperature, an upgraded design and the real-time gas cooling were performed in 2016. Two kinds of cooling gas, helium (He) and argon (Ar) were tested on the FLiLi system prior to the experiment. It was found that the cooling rates of He and Ar at 2.5 MPa are 34.2 ℃/min, 10.2 ℃/min or 31.7 ℃/kL and 28.1 ℃/kL, respectively. The cooling performance of He is more effective than Ar. Experimental results show that the real-time He cooling could effectively contain the FLiLi surface temperature increase and prevent the strong passive evaporation of lithium during plasma discharges. Limiter heat flux up to 0.2 MW/m2 was removed during ohmic discharge with 2.5 MPa He gas. Finally, Because of the upgraded design and real-time gas cooling, the surface of FLiLi was not damaged by heat flux after entire plasma discharge.

Self‐Actuating Electrocaloric Cooling Fibers

AbstractSolid‐state cooling fibers comprising an electrocaloric polymer, poly(vinylidene fluoride‐trifluoroethylene‐chlorofluoroethylene) terpolymer, spray‐coated on a conductive fiber core electrode, and a coaxially coated single‐walled carbon nanotubes outer electrode are reported. The fiber coolers can be less than 160 µm thin and more than 8 cm long. Measured cooling ΔT of the EC fibers is 0.7 °C at an electric field of 100 V µm−1 applied between the electrodes. The fiber coolers are flexible; 2000 cycles of repeated bending to a 2.5 mm curvature radius do not significantly degrade the cooling ΔT. Self‐actuated bending of the fibers is observed during the EC operation, which allows the EC fibers to move heat from one location to another without any additional driving mechanisms such as electromagnetic motors, pumps, or electrostatic actuation that are commonly used in conventional coolers. The self‐actuating EC fibers represent the first ever active cooler in a thin fiber form factor.

Reliability comparison of natural convection and forced circulation configurations of a FBR thermo-siphon decay heat removal system

Natural convection based passive decay heat removal systems are increasingly being deployed in the newer designs of nuclear reactors with the expectation that they enhance reliability and robustness owing to the elimination of reliance on human operators and external electrical power supply. In the absence of demonstrated experience with passive systems, difficulty in testing them on the field and possible range of phenomena which can degrade their performance, in some designs part of the redundant passive circuits are fitted with pumps to alleviate concerns regarding passive system performance. In this study the two types of designs, one with a set of 4 passive thermo-siphon loops and another with electro-magnetic pumps in part or all of the thermo-siphon loops are studied to bring out the reliability aspects. The decay heat removal function failure frequency is analyzed considering, electromagnetic pump integrity, changes in human interaction aspects for the two different configurations. It is observed that the introduction of electromagnetic pumps in two out of four loops increases the decay heat removal function failure frequency by approximately 64%. If electromagnetic pumps are introduced in all the four loops, the decay heat removal function failure frequency increases by an order. The results are highly sensitive to electromagnetic pump reliability. This study indicates that, there is no change in the uncertainty propagated from input parameters to response parameters, there is no significant advantage in terms of flexibility gained for certain operator actions and higher levels of reliability need to be achieved for the electromagnetic pump if it is to be introduced in all the four loops as compared to introduction in only two loops.

A 50 kW Liquid-Lithium Target for BNCT and Material-Science Applications

A compact Liquid Lithium Target (LiLiT) has been operating at SARAF for several years with beam power of several kW (1.9-2.5 MeV, up to 2 mA). When bombarding the lithium with low energy protons neutrons are generated. The neutron source, mainly used for nuclear astrophysics research, was decommissioned in 2016 towards an upgraded model - with possible applications to Boron Neutron Capture Therapy (BNCT) and material-science studies. The improved version has been designed to sustain 50 kW proton beam power (2.5 MeV, ~20 mA) to provide sufficient neutron flux required for clinical BNCT application. The new model has a 50 mm wide lithium jet to enable dissipation of the higher beam power and an improved heat exchanger to remove the power to a secondary cooling loop. A new Annular Linear INduction electro-magnetic pump (ALIN) has been designed and built to provide the required lithium flow rate. Other mechanical improvements facilitate the maintenance of the system and the robustness of operation. Radiological risks due to the 7Be produced in the reaction are reduced by using an integrated lead shielding of the lithium reservoir. An integrated neutron moderator is being designed to adjust the neutron energy to the spectrum best suited to BNCT. A low power (6 kW) model of the new design with a narrower nozzle (18 mm wide) and a rotating-magnet electro-magnetic pump is operating at SARAF to support the ongoing astrophysics and nuclear research program [1], [2]. To fulfill clinical BNCT, the upgraded LiLiT model will require an accelerator of appropriate energy and intensity. The design features of the new system are presented in this paper.

Improvement of flow and efficiency characteristics of electromagnetic pump using vibration

Improvement of flow and efficiency characteristics of electromagnetic pump using vibration

Biologically inspired transport of solid spherical nanoparticles in an electrically-conducting viscoelastic fluid with heat transfer

Bio-inspired pumping systems exploit a variety of mechanisms including peristalsis to achieve more efficient propulsion. Non-conducting, uniformly dispersed, spherical nanosized solid particles suspended in viscoelastic medium forms a complex working matrix. Electromagnetic pumping systems often employ complex working fluids. A simulation of combined electromagnetic bio-inspired propulsion is observed in the present article. Currents formation has increasingly more applications in mechanical and medical industry. A mathematical study is conducted for MHD pumping of a bi-phase nanofluid coupled with heat transfer in a planar channel. Two-phase model is employed to separately identity the effects of solid nanoparticles. Base fluid employs Jeffery?s model to address viscoelastic characteristics. The model is simplified using long wavelength and creeping flow approximations. The formulation is taken to wave frame and non-dimensionalise the equations. The resulting boundary value problem is solved analytically, and exact expressions are derived for the fluid velocity, particulate velocity, fluid-particle temperature, fluid and particulate volumetric flow rates, axial pressure gradient and pressure rise. The influence of volume fraction density, Prandtl number, Hartmann number, Eckert number, and relaxation time on flow and thermal characteristics is evaluated in detail. The axial flow is accelerated with increasing relaxation time and greater volume fraction whereas it is decelerated with greater Hartmann number. Both fluid and particulate temperature are increased with increment in Eckert and Prandtl numbers, whereas it is reduced when the volume fraction density increases. With increasing Hartmann number pressure rise is reduced

Optimization of outer core to reduce end effect of annular linear induction electromagnetic pump in prototype Generation-IV sodium-cooled fast reactor

An annular linear induction electromagnetic pump (ALIP) which has a developed pressure of 0.76 bar and a flow rate of 100 L/min is designed to analysis end effect which is main problem to use ALIP in thermohydraulic system of the prototype generation-IV sodium-cooled fast reactor (PGSFR). Because there is no moving part which is directly in contact with the liquid, such as the impeller of a mechanical pump, an ALIP is one of the best options for transporting sodium, considering the high temperature and reactivity of liquid sodium. For the analysis of an ALIP, some of the most important characteristics are the electromagnetic properties such as the magnetic field, current density, and the Lorentz force. These electromagnetic properties not only affect the performance of an ALIP, but they additionally influence the end effect. The end effect is caused by distortion to the electromagnetic field at both ends of an ALIP, influencing both the flow stability and developed pressure. The electromagnetic field distribution in an ALIP is analyzed in this study by solving Maxwell's equations and using numerical analysis.

The electromagnetic field distribution in the 1D layered quasiperiodic dispersive media

In the paper, we analyze the layer-by-layer electromagnetic field distribution in a quasiperiodic dispersive aluminum photonic crystal film. We propose the new way to calculate such structures without the finite-difference time-domain (FDTD) numerical computing agreed with both the experimental spectrum and the FDTD simulation. Also, we found the first pore electromagnetic pumping at the photonic bandgap edge which is useful for the various fundamental and engineering applications.

Stabilization of ultrashort pulses by external pumping in an array of carbon nanotubes subject to piezoelectric effects

We study the combined effects of electromagnetic pumping and piezoelectric damping on the propagation of ultrashort pulses in carbon nanotubes. Based on Maxwell’s equations, an effective equation is obtained for the vector potential of the electromagnetic field, which takes into account both the dissipation of the pulse field associated with piezoelectric effects due to the oscillations of the heavy nuclei of the medium and the pumping from an external electromagnetic wave. Our analysis shows that, when the dissipative piezoelectric effects are properly compensated through external pumping, a stable propagation of the ultrashort pulses is achievable. Specifically, we demonstrate the stability of the steady-state form of the electromagnetic pulse at long time scales with variations in various system parameters, including the absorption coefficient of heavy ions as well as the initial pulse field distribution. In addition, the stability of the pulse with respect to angular perturbations—breaking the axisymmetry of the pulse distribution—is substantiated.

Magnetohydrodynamic bio-nano-convective slip flow with Stefan blowing effects over a rotating disc

Microfluidic-related technologies and micro-electromechanical systems–based microfluidic devices have received applications in science and engineering fields. This article is the study of a mathematical model of steady forced convective flow past a rotating disc immersed in water-based nanofluid with microorganisms. The boundary layer flow of a viscous nanofluid is studied with multiple slip conditions and Stefan blowing effects under the magnetic field influence. The microscopic nanoparticles move randomly and have the characteristics of thermophoresis, and it is being considered that the change in volume fraction of the nanofluid does not affect the thermo-physical properties. The governing equations are nonlinear partial differential equations. At first, the nonlinear partial differential equations are converted to system of nonlinear ordinary differential equations using suitable similarity transformations and then solved numerically. The influence of relevant parameters on velocities, temperature, concentration and motile microorganism density is illustrated and explained thoroughly. This investigation indicated that suction provides a better medium to enhance the transfer rate of heat, mass and microorganisms compared to blowing. This analysis has a wide range engineering application such as electromagnetic micro pumps and nanomechanics.

Study on performance of micro heat dissipation system base on liquid metal

This paper introduces an advanced liquid metal microcirculation system that uses a liquid metal cycle driven by an electromagnetic pump to achieve heat dissipation. The overall thickness of the structure can be as flimsy as 0.9mm, and the heat dissipation capacity is more than twice that of the corresponding ultra-thin heat pipe. This paper analyzes the performance of the complex by experimenting with the sample and comparing it with the software simulation results, and demonstrates the theoretical analysis method of the liquid metal microcirculation system.

Transient amplification characteristics of frequency modulated wave in semiconductor plasmas

We perform an analytical investigation of modulational interaction of an electromagnetic pump wave in a transversely magnetized weakly polar semiconductor plasma medium. Based on the hydrodynamic model, a critical examination of frequency modulational amplification is made in a moderately doped III–V semiconductor crystal (n-GaAs) duly shined by pulsed 10.6 µm CO2 laser. The effect of electron-LO phonon interaction and coupled magnetoplasma excitations on the nonlinear interaction of a laser beam adds new dimension to the analysis. Steady state and transient gain coefficients, threshold pump intensity and optimum-pulse duration for the onset of modulational instability are estimated. The paper concentrates on the study of gain characteristics mainly in transient region. Effect of doping and applied magnetic field on the threshold pump intensity and growth rate has been significantly analysed. Graphical analysis interprets strong dependence of transient amplification characteristics on these parameters. So a judicious choice of physical parameters may develop growth at much lower pump intensity improving the cost effectiveness of the system. These results may help to be important for understanding and improving the performance of modulator.