scholarly journals Numerical Study of the Magnetic Damping Effect on the Sloshing of Liquid Oxygen in a Propellant Tank

Fluids ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 88
Author(s):  
Yutaro Furuichi ◽  
Toshio Tagawa
Keyword(s):  
Magnetic Field ◽  
Numerical Study ◽  
Pressure Fluctuations ◽  
Liquid Oxygen ◽  
Magnetic Flux Density ◽  
Baffle Plate ◽  
Two Phase ◽  
Gaseous Oxygen ◽  
Damping Effect ◽  
3.0 T

Nowadays, the use of baffle plates is anticipated to be one of potential devices used to dampen the sloshing of propellant in rocket tanks. However, some of previous studies reported that the use of a baffle plate may cause larger pressure fluctuations in the tank. In this study, aiming at damping the sloshing without a baffle plate, we paid attention to the characteristic that liquid oxygen is paramagnetic and numerically investigated damping effect of a magnetic field when liquid oxygen sloshing occurs. An incompressible gas–liquid two-phase flow of gaseous oxygen and liquid oxygen was assumed in a spherical spacecraft tank with a diameter of 1 m in a non-gravitational field, and a triangular impact force was assumed to be imposed as the excitation force. In addition, an electric circular coil was placed outside the spherical tank to generate a static magnetic field. For the sake of simplicity, the effect of heat was not taken into consideration. As a result of computation, the sloshing was damped to a certain extent when the magnetic flux density at the coil center was 1.0 T, and a sufficient damping effect was obtained by setting it to 3.0 T. In fact, it is anticipated that less than 3.0 T is sufficient if the coil is placed on the tank surface. This may contribute to damping of the movement of the center of gravity of a spacecraft and prevention of mixing of ullage gas into the piping.

Numerical Study on the Mechanism of Heat Transfer Enhancement in Fe3O4 Nanoferrofluids With Magnetic Field

2019 ◽  
Author(s):  
Chenfei Wang ◽  
Dongdong Gao ◽  
Minli Bai ◽  
Peng Wang ◽  
Yubai Li
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Fe3o4 Nanoparticles ◽  
Volume Fraction ◽  
Numerical Study ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Enhancement Of Heat Transfer

Abstract Nanofluids is reported to significantly enhance heat transfer but with little cost of pressure loss. To further the enhancement of heat transfer using Fe3O4 nanofluids, a magnetic field is employed to control the trajectory of Fe3O4 nanoparticles. A numerical study is conducted with commercial soft ANSYS FLUENT and the simulations are done with a two-phase flow approach named Euler-Lagrange. By comparing heat transfer of laminar flow in a horizontal tube with magnetic field or not, various volume fraction (0.5%/2%) and Reynolds numbers (Re = 200–1000) are considered. Results show that magnetic field contributes an average 4% promotion in convective heat transfer coefficients compared with the condition of no magnet. The mechanism of the enhancement of heat transfer with magnetic field is explored based on the analysis of velocity field. Fe3O4 Nanoparticles move up and down under the magnetic force, and convective heat transfer is enhanced because of the disturbance of the Fe3O4 nanoparticles. Slip flow between the base fluid and nanoparticles also contributes to the enhancement of heat transfer.

scholarly journals Thermomagnetic Convection of Paramagnetic Gas in an Enclosure under No Gravity Condition

Fluids ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 49 ◽  
Author(s):  
Kewei Song ◽  
Shuai Wu ◽  
Toshio Tagawa ◽  
Weina Shi ◽  
Shuyun Zhao
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Heat Transfer Performance ◽  
Magnetic Energy ◽  
Space Environment ◽  
Magnetic Flux Density ◽  
Transfer Performance ◽  
Gaseous Oxygen ◽  
Thermomagnetic Convection ◽  
Energy Product

The thermomagnetic convection of paramagnetic gaseous oxygen in an enclosure under a magnetic field was numerically studied to simulate the thermomagnetic convection in a space environment with no gravity. The magnetic field in the enclosure was non-uniform and was generated by a permanent magnet which had a high magnetic energy product. The magnet was placed at different locations along one of the adiabatic walls with magnetic poles perpendicular to the hot and cold walls of the enclosure. The heat transfer performance, flow field, and temperature field were studied with each location of the magnet. The results show that the thermomagnetic convection in the enclosure was obviously affected by the location of the magnet. There was an optimum magnet location in terms of the best heat transfer performance in the enclosure. The optimum magnet location changed slightly and moved toward the hot wall as the magnetic flux density increased. The value of the Nusselt number, defined as the ratio of convection to conduction, reached up to 2.54 in the studied range of parameters. By optimizing the magnet location, the convection was enhanced by up to 77% at the optimum magnet location.

scholarly journals Numerical Study of the Effect of Magnetic Field on Nanofluid Heat Transfer in Metal Foam Environment

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Hamid Shafiee ◽  
Elaheh NikzadehAbbasi ◽  
Majid Soltani
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Porous Medium ◽  
Porous Media ◽  
Fluid Flow ◽  
Volume Fraction ◽  
Numerical Study ◽  
Computational Simulation ◽  
Thermodynamic Efficiency ◽  
Two Phase

The magnetic field can act as a suitable control parameter for heat transfer and fluid flow. It can also be used to maximize thermodynamic efficiency in a variety of fields. Nanofluids and porous media are common methods to increase heat transfer. In addition to improving heat transfer, porous media can increase pressure drop. This research is a computational simulation of the impacts of a magnetic field induced into a cylinder in a porous medium for a volume fraction of 0.2 water/Al2O3 nanofluid with a diameter of 10 μm inside the cylinder. For a wide variety of controlling parameters, simulations have been made. The fluid flow in the porous medium is explained using the Darcy-Brinkman-Forchheimer equation, and the nanofluid flow is represented utilizing a two-phase mixed approach as a two-phase flow. In addition, simulations were run in a slow flow state using the finite volume method. The mean Nusselt number and performance evaluation criteria (PEC) were studied for different Darcy and Hartmann numbers. The results show that the amount of heat transfer coefficient increases with increasing the number of Hartmann and Darcy. In addition, the composition of the nanofluid in the base fluid enhanced the PEC in all instances. Furthermore, the PEC has gained its highest value at the conditions relating to the permeable porous medium.

scholarly journals MHD CASSON NANOFLUID FLOW OVER A STRETCHING SURFACE EMBEDDED IN A POROUS MEDIUM: EFFECTS OF THERMAL RADIATION AND SLIP CONDITIONS

2021 ◽  
Vol 51 (4) ◽  
pp. 229-239
Author(s):  
Sameh E. Ahmed ◽  
R.A Mohamed ◽  
A.M Ali ◽  
A.J Chamkha ◽  
M.S Soliman
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Thermal Radiation ◽  
Numerical Study ◽  
Physical Parameters ◽  
Radiation Parameter ◽  
Two Phase ◽  
Casson Nanofluid ◽  
Non Linear ◽  
The Magnetic Field

This article presents a numerical study for a magnetohydrodynamic flow of a non-Newtonian Casson nanofluid over a stretching sheet embedded in a porous medium under the impacts of non-linear thermal radiation, heat generation/absorption, Joule heating and slips boundary conditions. A two-phase nanofluid model is applied to represent the nanofluid mixture. The porous medium is represented via the Darcy model. A similar solution is obtained for the governing equations and a numerical treatment based on the Runge-Kutta method is conducted to the resulting system of equations.  In this study, the controlling physical parameters are the Casson fluid parameter , the magnetic field , the radiation parameter , the Brownian motion parameter  and the thermophoresis parameter . The obtained results reveal that an increase in the Casson parameter enhances both of the local Nusselt and the Sherwood number while they are reduced as the non-linear radiation parameter increases. In addition, an increase in the magnetic field parameter supports the skin friction coefficient regardless the value of the Casson parameter.

Numerical study on the bubble rising behavior in liquid oxygen under magnetic field

Cryogenics ◽  
2019 ◽  
Vol 101 ◽  
pp. 43-52
Author(s):  
Rui-Ping Zhang ◽  
Shi-Ran Bao ◽  
Chen-Jie Gu ◽  
Li-Min Qiu ◽  
Xiao-Qin Zhi ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Numerical Study ◽  
Liquid Oxygen ◽  
Bubble Rising

A comparative analysis on the single-phase and two-phase mixture models for calculation of ferrofluid convective heat transfer in the presence of a magnetic field: a numerical study

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hamed Jafari ◽  
Mohammad Goharkhah ◽  
Alireza Mahdavi Nejad
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Single Phase ◽  
Numerical Study ◽  
Phase Method ◽  
Two Phase ◽  
Content Type ◽  
Phase Models

Purpose This paper aims to analyze the accuracy of the single and two-phase numerical methods for calculation of ferrofluid convective heat transfer in the presence of a magnetic field. The findings of current study are compared with previous single-phase numerical results and experimental data. Accordingly, the effect of various parameters including nanoparticles concentration, Reynolds number and magnetic field strength on the performance of the single and two-phase models are evaluated. Design/methodology/approach A two-phase mixture numerical study is carried out to investigate the influence of four U-shaped electromagnets on the hydrodynamic and thermal characteristics of Fe3O4/Water ferrofluid flowing inside a heated channel. Findings It is observed that the applied external magnetic field signifies the convective heat transfer from the channel surface, despite local reduction at a few locations. The maximum heat transfer enhancement is predicted as 23% and 25% using single and two-phase models, respectively. The difference between the results of the two models is mainly attributed to the slip velocity effect which is accounted for in the two-phase model. The magnetic field gradient leads to a significant increase in the slip velocity which in turn causes a slight difference in velocity and temperature profiles obtained by the single and two-phase models in the magnetic field region. According to percentage error calculation, the two-phase method is generally more accurate than the single-phase method. However, the percentage error of both models improves by decreasing either magnetic field intensity or Reynolds number. Originality/value For the first time in the literature, to the best of the authors’ knowledge, the current work analyzes the accuracy of the single and two phase numerical methods for calculation of ferrofluid convective heat transfer in the presence of a magnetic field.

THE INFLUENCE OF A MAGNETIC FIELD ON THE DIELECTRIC CONSTANTS OF GASEOUS AND LIQUID NITROGEN AND OXYGEN

1935 ◽  
Vol 13a (6) ◽  
pp. 111-119 ◽  
Author(s):  
Allan C. Young
Keyword(s):  
Magnetic Field ◽  
Positive Result ◽  
Experimental Determination ◽  
Resonance Method ◽  
Dielectric Constants ◽  
Liquid Oxygen ◽  
Gaseous Oxygen ◽  
The Magnetic Field ◽  
Increased Pressure

The results of an experimental determination of the effect of a magnetic held on the dielectric constants of gaseous and liquid oxygen and nitrogen are given. With the gases a balanced resonance method was used, and with the liquids, a special bridge. The only positive result obtained was with gaseous oxygen at a pressure of 100 atm., and this can be accounted for quantitatively by the increased pressure of the oxygen in the magnetic field.

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