A Non-Dimensional Analysis to Characterize Thermomagnetic Convection of a Temperature Sensitive Magnetic Fluid in a Flow Loop

2013 ◽  
Author(s):  
Giti Karimi-Moghaddam ◽  
Richard D. Gould ◽  
Subhashish Bhattacharya
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Simulation Software ◽  
Temperature Sensitive ◽  
Flow Loop ◽  
Numerical Studies ◽  
Fluid Properties ◽  
1D Model ◽  
Phase Temperature ◽  
Geometric Length

This paper presents results from theoretical and numerical studies of a single-phase, temperature sensitive magnetic fluid operating under steady-state laminar flow conditions in a partially heated thermomagnetic circulation loop under the influence of an external magnetic field (created by a solenoid). A one-dimensional theoretical model has been developed using scaling arguments to characterize thermomagnetic circulation in this loop in terms of the geometric length scales, magnetic fluid properties, and strength of the imposed magnetic field. In parallel to this theoretical analysis, supporting numerical simulations using COMSOL Multiphysics simulation software have been undertaken to obtain data for use in this 1D model. A correlation for the non-dimensional heat transfer (Nusselt number) as a function of the appropriate magnetic Rayleigh number and a correlation for the mass flow rate based on the system’s properties are developed.

A Nondimensional Analysis to Characterize Thermomagnetic Convection of a Temperature Sensitive Magnetic Fluid in a Flow Loop

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Giti Karimi-Moghaddam ◽  
Richard D. Gould ◽  
Subhashish Bhattacharya
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Magnetic Fluid ◽  
Model Comparison ◽  
Simulation Software ◽  
Temperature Sensitive ◽  
Flow Loop ◽  
Fluid Properties ◽  
1D Model ◽  
Geometric Length

This paper presents results from theoretical and numerical studies of a single-phase, temperature sensitive magnetic fluid operating under steady-state laminar flow conditions in a partially heated thermomagnetic circulation loop under the influence of an external magnetic field (created by a solenoid). A one-dimensional theoretical model has been developed using scaling arguments to characterize thermomagnetic circulation in this loop in terms of the geometric length scales, magnetic fluid properties, and the strength of the imposed magnetic field. In parallel to this theoretical analysis, supporting numerical simulations using Comsol Multiphysics simulation software have been undertaken to obtain data for use in this 1D model. Comparison between experimental data and numerical simulation results and also a grid sensitivity analysis was carried out to validate the numerical simulation. A correlation for the nondimensional heat transfer (Nusselt number) as a function of the appropriate magnetic Rayleigh number and a correlation for the mass flow rate based on the system's properties are developed.

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.

Development of magnetically-driven cooling device with concentric pipe structure

2019 ◽  
Vol 233 (13) ◽  
pp. 4754-4763 ◽  
Author(s):  
H Yamaguchi ◽  
H Yamasaki ◽  
T Bessho
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Thermal Energy ◽  
Waste Heat ◽  
Flow Behavior ◽  
Temperature Sensitive ◽  
Cooling Device ◽  
External Energy ◽  
Long Distance ◽  
The Magnetic Field

Temperature-sensitive magnetic fluid is a smart material for energy carrier. The most interesting aspect of temperature-sensitive magnetic fluid is that the thermal flow behavior is actively controlled by means of magnetic field. Based on the effect of the temperature-dependent magnetization, temperature-sensitive magnetic fluid can be utilized as an energy conversion system, which can automatically transfer the thermal energy. The advantage in the engineering application can be derived from the fact that there would be entirely no external energy consumption, with which large amount heat can be transported for a long distance without any external power consumption. Taking into account of the advantage, a magnetically-driven cooling device is newly designed for recovering of low- to high-temperature waste heat in the present study. The basic performance of the cooling device with concentric pipe structure is investigated experimentally and data gained in the device is examined in detail in view of magneto-hydrodynamics. In the present study, electromagnet is used as an external magnetic field for the purpose of investigating basic heat transfer characteristics of the present experimental device, so that the magnetic field can be continuously altered. However, it can be easily replaced to a permanent for the practical device without additional electrical energy. The results show that the binary temperature-sensitive magnetic fluid can be circulated freely with a high flow rate of 2.0 × 10−3 m3/min by imposing the magnetic field of 55.8 kA/m. It is found that the newly designed device can transfer thermal energy more than 250 W with overall system efficiency of 11.0% at air temperature of 623 K.

Surface of a magnetic fluid containing magnetizable bodies in an applied uniform magnetic field

2008 ◽  
Vol 44 (2) ◽  
pp. 175-182 ◽  
Author(s):  
K. Zimmermann ◽  
V.A. Naletova ◽  
I. Zeidis ◽  
V.A. Turkov ◽  
D.A. Pelevina ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Uniform Magnetic Field
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