Experimental Measurements of Velocity, Potential, and Temperature Distributions in Liquid Aluminum During Electromagnetic Stirring

2003 ◽  
Vol 70 (3) ◽  
pp. 351-358 ◽  
Author(s):  
S. I. Bakhtiyarov ◽  
R. A. Overfelt ◽  
A. J. Meir ◽  
P. G. Schmidt
Keyword(s):  
Experimental Technique ◽  
Molten Aluminum ◽  
Velocity Potential ◽  
Liquid Aluminum ◽  
Electromagnetic Stirring ◽  
Temperature Profiles ◽  
Cylindrical Container ◽  
Temperature Distributions ◽  
Angular Velocities ◽  
Probe Velocity

An experimental technique has been developed to measure both axial and transverse velocities and temperature distribution in molten aluminum. Couette flow of liquid aluminum, lead, tin, and low melting alloy in cylindrical container was chosen for calibration of the experimental technique and the magnetic probe. Velocity and temperature profiles for liquid aluminum rotating in cylindrical container at different angular velocities are obtained for two different values of the depth. We determined that the velocity values increase with magnetic induction.

Velocity, Potential, and Temperature Distributions in Molten Metals During Electromagnetic Stirring: Part I — Experimental Measurements

1999 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt ◽  
Amnon J. Meir ◽  
Paul G. Schmidt
Keyword(s):  
Experimental Technique ◽  
Magnetic Induction ◽  
Liquid Aluminum ◽  
Quadratic Function ◽  
Azimuthal Velocity ◽  
Cylindrical Container ◽  
Molten Metals ◽  
Angular Velocities ◽  
Probe Velocity ◽  
The Relationship

Abstract An experimental technique has been developed to measure the local velocity in molten metals. Couette flow of liquid aluminum, lead, tin and low melting alloy in cylindrical container was chosen for calibration of the experimental technique and the magnetic probe. Velocity and temperature profiles for liquid aluminum rotating in cylindrical container at different angular velocities are obtained for two different values of the depth. We determined that the velocity values increase with magnetic induction, and the relationship between the normalized azimuthal velocity and the magnetic induction can be expressed by quadratic function.

Elimination of Iron in Molten Aluminum Scrap by Electromagnetic Stirring Technique

PRICM ◽  
2013 ◽  
pp. 1041-1047
Author(s):  
Gyuchang Lee ◽  
Myounggyun Kim ◽  
Joonpyo Park
Keyword(s):  
Molten Aluminum ◽  
Electromagnetic Stirring ◽  
Aluminum Scrap

scholarly journals On the Thermal Regime of an Arctic Valley Glacier: A Study of White Glacier, Axel Heiberg Island, N.W.T., Canada

1987 ◽  
Vol 33 (114) ◽  
pp. 200-211 ◽  
Author(s):  
Heinz Blatter
Keyword(s):  
Climatic Conditions ◽  
Temperature Profiles ◽  
Two Dimensional ◽  
Temperature Minimum ◽  
Climatic Warming ◽  
Simple Scheme ◽  
Glacier Surface ◽  
Temperature Distributions ◽  
Valley Glacier ◽  
Simple Numerical Model

AbstractFrom 1974 to 1981, a total of 32 bore holes was drilled on White Glacier and vertical ice-temperature profiles measured. The data obtained allowed the construction of three longitudinal and four transverse profiles of the two-dimensional temperature distributions. Thus, an extensive layer of temperate or near-temperate ice was discovered close to the bedrock in the lowest part of the glacier tongue. It was also found that the temperature distribution cannot be in a steady state, since there is a temperature minimum 100–150 m below the glacier surface in the accumulation area. A simple numerical model calculation shows that this minimum can be mostly explained by the general climatic warming since 1880. The 10 m temperatures show diffuse relations to climatic conditions and balance zones. A simple scheme for extrapolating “surface temperatures” is discussed.

scholarly journals On the Thermal Regime of an Arctic Valley Glacier: A Study of White Glacier, Axel Heiberg Island, N.W.T., Canada

1987 ◽  
Vol 33 (114) ◽  
pp. 200-211 ◽  
Author(s):  
Heinz Blatter
Keyword(s):  
Climatic Conditions ◽  
Temperature Profiles ◽  
Two Dimensional ◽  
Temperature Minimum ◽  
Climatic Warming ◽  
Simple Scheme ◽  
Glacier Surface ◽  
Temperature Distributions ◽  
Valley Glacier ◽  
Simple Numerical Model

AbstractFrom 1974 to 1981, a total of 32 bore holes was drilled on White Glacier and vertical ice-temperature profiles measured. The data obtained allowed the construction of three longitudinal and four transverse profiles of the two-dimensional temperature distributions. Thus, an extensive layer of temperate or near-temperate ice was discovered close to the bedrock in the lowest part of the glacier tongue. It was also found that the temperature distribution cannot be in a steady state, since there is a temperature minimum 100–150 m below the glacier surface in the accumulation area. A simple numerical model calculation shows that this minimum can be mostly explained by the general climatic warming since 1880. The 10 m temperatures show diffuse relations to climatic conditions and balance zones. A simple scheme for extrapolating “surface temperatures” is discussed.

On the analogy between thermal and rotational hydrodynamic stability

1966 ◽  
Vol 24 (1) ◽  
pp. 165-176 ◽  
Author(s):  
Walter R. Debler
Keyword(s):  
Temperature Distribution ◽  
Initial Temperature ◽  
Rotating Cylinder ◽  
Temperature Profiles ◽  
Convection Pattern ◽  
Onset Of Convection ◽  
Single Vortex ◽  
Angular Velocities ◽  
The Stability ◽  
Rayleigh Numbers

The correspondence between the eigenvalues for the problem of the onset of convection in a fluid confined between two horizontal plates and for the stability of viscous flow between two cylinders rotating at almost the same angular velocity has been known for some time. The recent work of Chandrasekhar (1961) has prompted the extension of the analogy to a larger group of rotating cylinder problems and their associated convection cases in which the primary temperature distribution is parabolic. This paper shows the analogy between these two problems and presents data which give the corresponding temperature distribution for a given ratio of angular velocities between the two cylinders. The equivalent Rayleigh numbers are listed for the Taylor numbers given by Chandrasekhar (1954). The eigenfunctions for several of the parabolic temperature profiles are determined. These results show that the single vortex convection pattern becomes a double vortex for certain initial temperature distributions. The critical Rayleigh numbers for the stability of a layer of water which is near 4 °C is also found by analogy.

Investigating the Potential of TiB2-Based Composites with Ti and Fe Additives as Wettable Cathode

2012 ◽  
Vol 706-709 ◽  
pp. 655-660
Author(s):  
Hamed Heidari ◽  
Houshang Alamdari ◽  
Dominique Dubé ◽  
Robert Schulz
Keyword(s):  
Molten Aluminum ◽  
Milling Time ◽  
Sessile Drop ◽  
Liquid Aluminum ◽  
Processing Parameters ◽  
Optical Microscope ◽  
Considerable Effect ◽  
Starting Mixture ◽  
Sintering Method ◽  
Microstructural Studies

In this work, porous TiB2 ceramics were consolidated by pressureless sintering method using metallic Ti and Fe as additives in order to perform sintering at temperatures lower than 1700°C. It was shown that processing parameters including milling time of the starting mixture had a considerable effect on final properties of sintered specimens and their behavior in molten aluminum. Microstructural studies were carried out using optical microscope, SEM and EPMA. It was found that specimens with uniform and crack-free microstructure could be produced using the pre-mixed powders milled for as low as 30 min prior to compaction and sintering. Sessile drop test was performed on the specimens milled for 30 and 240 minutes. Their interaction with molten aluminum was also studied. It was found that 30 min milling time resulted in better electrical conductivity, wettability and stability in liquid aluminum.

scholarly journals Experimental Verification of Modeled Thermal Distribution Produced by a Piston Source in Physiotherapy Ultrasound

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
M. I. Gutierrez ◽  
S. A. Lopez-Haro ◽  
A. Vera ◽  
L. Leija
Keyword(s):  
Acoustic Field ◽  
Temperature Profiles ◽  
Acoustic Intensity ◽  
Fe Method ◽  
Thermal Distribution ◽  
Temperature Modeling ◽  
Temperature Distributions ◽  
Acoustic Profile ◽  
Thermal Patterns ◽  
The Ideal

Objectives. To present a quantitative comparison of thermal patterns produced by the piston-in-a-baffle approach with those generated by a physiotherapy ultrasonic device and to show the dependency among thermal patterns and acoustic intensity distributions.Methods. The finite element (FE) method was used to model an ideal acoustic field and the produced thermal pattern to be compared with the experimental acoustic and temperature distributions produced by a real ultrasonic applicator. A thermal model using the measured acoustic profile as input is also presented for comparison. Temperature measurements were carried out with thermocouples inserted in muscle phantom. The insertion place of thermocouples was monitored with ultrasound imaging.Results. Modeled and measured thermal profiles were compared within the first 10 cm of depth. The ideal acoustic field did not adequately represent the measured field having different temperature profiles (errors 10% to 20%). Experimental field was concentrated near the transducer producing a region with higher temperatures, while the modeled ideal temperature was linearly distributed along the depth. The error was reduced to 7% when introducing the measured acoustic field as the input variable in the FE temperature modeling.Conclusions. Temperature distributions are strongly related to the acoustic field distributions.

Benchmark Solution for the Prediction of Temperature Distributions During Radiofrequency Ablation of Cardiac Tissue

2004 ◽  
Vol 126 (4) ◽  
pp. 519-522 ◽  
Author(s):  
Ryan T. Roper and ◽  
Matthew R. Jones
Keyword(s):  
Cardiac Tissue ◽  
Numerical Solutions ◽  
Integral Transforms ◽  
Tissue Temperature ◽  
Temperature Profiles ◽  
Bioheat Equation ◽  
Temperature Distributions ◽  
Axial Temperature ◽  
Program Temperature ◽  
Benchmark Solution

Several studies on radiofrequency (RF) ablation are aimed at accurately predicting tissue temperature distributions by numerical solution of the bioheat equation. This paper describes the development of a solution that can serve as a benchmark for subsequent numerical solutions. The solution was obtained using integral transforms and evaluated using a C program. Temperature profiles were generated at various times and for different convection coefficients. In addition, a numerical model was developed using the same assumptions made in obtaining the benchmark solution. Comparison of surface and axial temperature profiles shows that the two solutions match very closely, cross validating the numerical methods used in evaluating both solutions.

Manipulation of Microfluidic Flows Using Time Dependent Wall Temperatures

2004 ◽  
Author(s):  
Tom Mautner
Keyword(s):  
Thermal Diffusion ◽  
Wall Temperature ◽  
Lattice Boltzmann ◽  
Channel Wall ◽  
Three Dimensional ◽  
Temperature Profiles ◽  
Thermal Coupling ◽  
Uniform Temperature ◽  
Temperature Distributions ◽  
Flow Through

One module in a bioagent detector currently under development involves a flow-through PCR module [1] [3] [4]. Conventional, flow-through PCR devices utilize three heaters to obtain the required temperatures in each zone, the length of which is specified by the required sample residence times. An alternate design uses two wall heaters with substrate conduction supplying the center zone temperature. The concept of using a conduction based PCR device led to an extensive computational study of various channel wall temperature profiles that would produce enhanced mixing in a variety of microfluidic devices. The results are applicable to micro channel designs in general even tough motivated by the conduction based PCR configuration. The lattice Boltzmann (LB) method was used to perform low Reynolds number (typically Re=0.10) simulations for two and three dimensional channel geometries having various wall temperature distributions. The momentum and thermal lattice Boltzmann equations were coupled via a body force term in the momentum equation. Initial computations using two- and three-heater configurations in two dimensions demonstrated excellent comparisons with published data provided that both the top and bottom walls were heated. If only one wall was heated, large vertical thermal gradients occurred resulting in non-uniform temperature fields. However, when the same conditions were applied to three dimensional channels, lower temperatures were observed in the center of the channel regardless of the wall temperatures or channel aspect ratio. Parametric studies were performed to evaluate the effects of thermal coupling, thermal diffusion coefficients, entrance temperatures, wall temperature configurations and channel geometry. If was found that moderate variation of the thermal diffusion coefficient produced only minor differences in the temperature field, and large changes in the thermal coupling magnitude demonstrated transition from natural to forced convection flows. The simulations also indicate that the largest effect on flow and temperature uniformity arises from the applied wall temperature distribution (various thickness channel walls). It was found, in 2D, that if the channel wall starts from ambient temperature, the applied heating, on the outer surfaces only, may not result in the desired wall or fluid temperatures. However, once the channel walls are heated to a uniform temperature, excellent temperature distributions are obtained for both thick and thin channel walls. Additionally, a checkerboard pattern of wall heaters was used to test its application to promoting mixing. Results were favorable in creating enhanced mixing; however, the temperature pattern did not produce uniform temperature profiles in the channel.

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