scholarly journals Development of a Magnetic Fluid Heating FEM Simulation Model with Coupled Steady State Magnetic and Transient Thermal Calculation

Mathematics ◽  
2021 ◽  
Vol 9 (20) ◽  
pp. 2561
Author(s):  
Jakob Vizjak ◽  
Miloš Beković ◽  
Marko Jesenik ◽  
Anton Hamler
Keyword(s):  
Steady State ◽  
Magnetic Fluid ◽  
Magnetic Particles ◽  
Fem Simulation ◽  
Thermal Calculation ◽  
Carrier Fluid ◽  
Laboratory Setup ◽  
Novel Approach ◽  
Thermal Calculations ◽  
Transient Thermal

Magnetic fluid hyperthermia has gained much attention in recent years due to its potential in cancer treatment. Magnetic fluid is a colloidal liquid made of nanoscale magnetic particles suspended in a carrier fluid. The properties of a commercial magnetic fluid consisting of maghemite (γ-Fe2O3) particles suspended in mineral oil were used in the scope of our research. The paper deals with a novel approach to the development of a magnetic fluid FEM model of a laboratory setup, with consideration of the electromagnetic steady state and thermal transient calculation soft coupling. Also, adjustment of the mathematical model was added in such a way that it enables a link between the magnetic and thermal calculations in commercial software. The effective anisotropy’s influence on the calculations is considered. The simulation was done for different magnetic field parameters. The initial temperature was also varied so that a direct comparison could be made between the simulation and the measurements. A good indicator of the accuracy of the simulation are the SAR values. The relative differences in SAR values were in the range from 4.2–24.9%. Such a model can be used for assessing the heating performance of a magnetic fluid with selected parameters. It can also be used to search for the optimal parameters required to design an optimal magnetic fluid.

A novel approach for estimating the magnetization curve of magnetic fluids

2017 ◽  
Vol 34 (6) ◽  
pp. 2063-2073 ◽  
Author(s):  
Marcin Szczech
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Numerical Simulations ◽  
Magnetic Fluid ◽  
Magnetization Curve ◽  
Magnetic Fluids ◽  
Content Type ◽  
Carrier Fluid ◽  
Novel Approach ◽  
The Difference

Purpose Magnetization is one of the most important parameters of magnetic fluids. The shape of the magnetization curve often determines the application of a fluid in a device. On the basis of the magnetization curve, it is also possible to estimate, for example, the distribution and size of the particles in a magnetic fluid carrier fluid. The aim of this paper is to present a new approach for estimating the magnetization curve. Design/methodology/approach The proposed method is an iterative method based on the measurement of magnetic induction on a test stand. To determine the magnetization curve, a numerical simulation of the magnetic field distributions for the preliminary magnetization curve should also be performed. Numerical simulations for modified forms of the magnetization curve are performed until the difference between the results obtained by the measurement and numerical simulation are the smallest. Findings This paper presents the results of magnetization curve research for ferrofluids and magnetorheological fluids. Originality/value The discussed method shows the possibilities of using numerical simulations of magnetic field distribution to determine the magnetic properties of magnetic fluids. This method may be an alternative for estimating the magnetization curve of the magnetic fluid compared to other methods.

A magnetic super lattice

1987 ◽  
Vol 45 ◽  
pp. 360-361 ◽  
Author(s):  
M.D. Bentzon ◽  
J. v. Wonterghem ◽  
A. Thölén
Keyword(s):  
Thermal Decomposition ◽  
Oleic Acid ◽  
Magnetic Fluid ◽  
Magnetic Particles ◽  
Carbon Film ◽  
Thick Layer ◽  
Amorphous Iron ◽  
Super Lattice ◽  
Carrier Liquid ◽  
Median Diameter

We report on the oxidation of a magnetic fluid. The oxidation results in magnetic super lattice crystals. The “atoms” are hematite (α-Fe2O3) particles with a diameter ø = 6.9 nm and they are covered with a 1-2 nm thick layer of surfactant molecules.Magnetic fluids are homogeneous suspensions of small magnetic particles in a carrier liquid. To prevent agglomeration, the particles are coated with surfactant molecules. The magnetic fluid studied in this work was produced by thermal decomposition of Fe(CO)5 in Declin (carrier liquid) in the presence of oleic acid (surfactant). The magnetic particles consist of an amorphous iron-carbon alloy. For TEM investigation a droplet of the fluid was added to benzine and a carbon film on a copper net was immersed. When exposed to air the sample starts burning. The oxidation and electron irradiation transform the magnetic particles into hematite (α-Fe2O3) particles with a median diameter ø = 6.9 nm.

The Analysis on the Starting Friction Torque Increase of Magnetic Fluid Revolving Sealing

2013 ◽  
Vol 275-277 ◽  
pp. 429-432 ◽  
Author(s):  
Yu Qiang Cai ◽  
Na Xing
Keyword(s):  
Magnetic Fluid ◽  
Magnetic Particles ◽  
Influence Factor ◽  
Magnetic Field Gradient ◽  
Friction Torque ◽  
Key Factor ◽  
Lower Temperature ◽  
Change Of Microstructure ◽  
Starting Torque ◽  
Main Influence

Abstract. Magnetic fluid revolving sealing is widely used in modern industry. In the process of application, it is founded that the starting friction torque is very large, particularly at lower temperature. This problem has become a key factor restricting the application of magnetic fluid rotation sealing. In this paper, the mechanism of starting torque increase is analyzed, based on the change of microstructure and its viscosity. After analysis , such conclusion is obtained , which can be described: to a certain sealing structure, the type of magnetic fluid, size distribution of magnetic particles as well as the working condition concluding temperature, magnetic field gradient and the revolving velocity of shaft is the main influence factor of starting friction torque . It is very useful to reduce the starting friction torque.

A novel approach for the estimation of the efficiency of steady-state fiber bed coalescence

2013 ◽  
Vol 104 ◽  
pp. 268-275 ◽  
Author(s):  
Dragan D. Govedarica ◽  
Radmila M. Šećerov Sokolović ◽  
Dunja S. Sokolović ◽  
Slobodan M. Sokolović
Keyword(s):  
Steady State ◽  
Novel Approach

Finite Element Analysis of a Gasketed Flange Joint Under Combined Internal Pressure and Thermal Transient Loading

2007 ◽  
Author(s):  
Muhammad Abid ◽  
Javed A. Chattha ◽  
Kamran A. Khan
Keyword(s):  
Finite Element Analysis ◽  
Steady State ◽  
Internal Pressure ◽  
Thermal Loading ◽  
Flange Joint ◽  
Element Analysis ◽  
Transient Loading ◽  
Thermal Transient ◽  
Transient Thermal ◽  
Bolted Flange

Performance of a bolted flange joint is characterized mainly by its ‘strength’ and ‘sealing capability’. A number of analytical and experimental studies have been conducted to study these characteristics only under internal pressure loading. In the available published work, thermal behavior of the pipe flange joints is discussed under steady state loading with and without internal pressure and under transient loading condition without internal pressure. The present design codes also do not address the effects of steady state and thermal transient loading on the structural integrity and sealing ability. It is realized that due to the ignorance of any applied transient thermal loading, the optimized performance of the bolted flange joint can not be achieved. In this paper, in order to investigate gasketed joint’s performance i.e. joint strength and sealing capability under combined internal pressure and transient thermal loading, an extensive nonlinear finite element analysis is carried out and its behavior is discussed.

Model and Algorithm for Thermal Performance Calculation of Power Station Boiler Based on Process Steady-State Simulation Theory

2013 ◽  
Vol 483 ◽  
pp. 587-593
Author(s):  
Hong Kai Liao ◽  
Yue Xi Yu ◽  
Yan Ling Wu ◽  
Wei Zhong
Keyword(s):  
Steady State ◽  
Thermal Performance ◽  
Simulation Theory ◽  
General Purpose ◽  
Thermal Calculation ◽  
Process Unit ◽  
Power Station ◽  
Steady State Simulation ◽  
Power Station Boiler ◽  
Performance Calculation

Thermal performance calculation is the core task of designing power station boiler. By abstracting generalized components and generalized fluid nodes, and defining the process unit and process section at the logic level, the universal physical model of boiler was built in a particular form of flowsheet. Meanwhile, a sequential modular approach was proposed as the main algorithm for boiler thermal calculation based on process system steady-state simulation theory. Two key problems in the algorithm, i.e., module calculations and the logics of calling the modules calculations were explained. Finally, a practically developed system BESS, which has excellent flexibility and extensibility was presented. It turns out that the model and algorithm can be successfully employed in developing the general-purpose software for boiler thermal calculation.

Investigation of Enhancement in Pool Boiling Heat Transfer of a Binary Temperature Sensitive Magnetic Fluid

2013 ◽  
Author(s):  
Giti Karimi-Moghaddam ◽  
Richard D. Gould ◽  
Subhashish Bhattacharya
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Magnetic Fluid ◽  
Boiling Heat Transfer ◽  
Magnetic Particles ◽  
Pool Boiling ◽  
Simulation Software ◽  
Temperature Sensitive ◽  
Magnetic Field Effects ◽  
Pool Boiling Heat Transfer

In this paper, the performance of pool boiling heat transfer using a binary temperature sensitive magnetic fluid in the presence of a non-uniform magnetic field is investigated numerically. By using a binary magnetic fluid, enhanced boiling heat transfer is obtained by thermomagnetic convection without deterioration of properties of the fluid. This work is aimed at gaining a qualitative understanding the magnetic field effects on boiling heat transfer enhancement of magnetic fluids. In order to accomplish this, the boiling process and the effects of position of the external magnetic field on flow pattern and heat transfer are investigated in a 2D rectangular domain using COMSOL Multiphysics simulation software. Finally, the boiling curves for a binary temperature sensitive magnetic fluid and its base fluid (without magnetic particles) are compared for various applied heat flux magnitudes.

Abstract 89: The Ventriculo-Ventricular Coupling Index: A Novel Approach to Assessing Biventricular Function

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Navin K Kapur ◽  
Mark J Aronovitz ◽  
Robert Blanton ◽  
Emily Mackey ◽  
Vikram Paruchuri ◽  
...  
Keyword(s):  
Heart Failure ◽  
Steady State ◽  
Left Ventricular ◽  
External Jugular Vein ◽  
Arterial Elastance ◽  
Left Heart Failure ◽  
Novel Approach ◽  
Coupling Index ◽  
Ventricular Efficiency ◽  
The Right

Bi-ventricular (Bi-V) function in primary pulmonary hypertension (PPH) or PH secondary to left heart failure (SPH) remains difficult to characterize. As a measure of ventricular efficiency, ventriculo-arterial coupling (VAC) is calculated as the ratio of effective arterial elastance (Ea) to end-systolic elastance (Ees). No measure currently assesses ventriculo-ventricular coupling (VVC). Therefore, we developed a novel catheter-based approach to quantify Bi-V function using pressure-volume loop (PVL) analysis and hypothesized that Bi-V VAC ratios, defined as the VVC index (VVCI), may discriminate PPH and SPH. Methods: Adult male mice (n=6/group) underwent constriction of the pulmonary artery (PAC) or thoracic aorta (TAC) to model PPH and SPH respectively. Sham-operated animals underwent a left thoracotomy. Closed chest simultaneous Bi-V catheterization was performed after 7 days in PPH and 10 weeks in SPH. Conductance catheters were used for right and left ventricular PVL analysis via the right external jugular vein and right common carotid artery under steady-state conditions and with variable preload. Results: Steady-state Bi-V PVL and changes in VAC ratios and the VVCI are shown below. In sham mice VAC ratios and the VVCI reflect optimal ventricular efficiency. In PPH, the VVCI is significantly increased, while in SPH, the VVCI is significantly decreased compared to controls. Conclusion: These results identify a novel method to quantify Bi-V function in mice and further show that the VVCI can distinguish PPH and SPH. These findings have important implications for examining cardiac function in preclinical and clinical studies of left- and right-sided heart failure.

Sign in / Sign up

Export Citation Format

Share Document