A nonsteady-state finite-elements model of the temperature field in the direct electric heating of a powder mixture

1988 ◽  
Vol 27 (3) ◽  
pp. 185-189
Author(s):  
A. I. Tsitrin ◽  
V. Ya. Belousov ◽  
A. V. Pilipchenko ◽  
A. N. Khomchenko ◽  
L. D. Lutsak
Keyword(s):  
Temperature Field ◽  
Finite Elements ◽  
Powder Mixture ◽  
Electric Heating ◽  
Nonsteady State ◽  
Finite Elements Model

Numerical Simulation of Temperature Field of Linear Friction Welding of 45# Carbon Steel

2012 ◽  
Vol 538-541 ◽  
pp. 1443-1446
Author(s):  
Ze Min Liu ◽  
Zheng Hua Guo ◽  
Shu Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Carbon Steel ◽  
Finite Elements ◽  
Friction Welding ◽  
Interface Temperature ◽  
Linear Friction Welding ◽  
Welding Interface ◽  
Linear Friction ◽  
Finite Elements Model

A 3D finite-elements model of 45# carbon steel of linear friction welding is built with the dynamic explicit code ABAQUS/explicit. The temperature field of workpiece, and the temperature change of center point of welding interface are showed in results. The center temperature of welding interface soars to 800°C, but the temperature of both ends of the welding interface are only 400°C or so at 0.75s. Then, the interface temperature rises slowly to about 920°C and maintains until welding ends.

A Study Regarding the Unsteady Heat Transfer and Phase Change

2014 ◽  
Vol 659 ◽  
pp. 353-358
Author(s):  
Gelu Coman ◽  
Cristian Iosifescu ◽  
Valeriu Damian
Keyword(s):  
Heat Transfer ◽  
Numerical Modeling ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Finite Elements ◽  
Experimental Research ◽  
Theoretical Study ◽  
Ice Formation ◽  
Unsteady Heat Transfer ◽  
Cooling Pipes

The paper presents the experimental and theoretical study for temperature distribution around the cooling pipes of an ice rink pad. The heat transfer in the skating rink track is nonstationary and phase changing. In case of skating rinks equipped with pipe registers, the temperature field during the ice formation process can’t be modeled by analytical methods. The experimental research was targeted on finding the temperatures in several points of the pad and also details on ice shape and quality around the pipes. The temperatures measured on the skating ring surface using thermocouples is impossible due to the larger diameter of the thermocouple bulb compared with the air-water surfaces thickness. For this reason we used to measure the temperature by thermography method, thus reducing the errors The experimental results were compared against the numerical modeling using finite elements.

Prediction of Rail Profile Wear with the Increase of Vehicle Speed

2013 ◽  
Vol 716 ◽  
pp. 659-662
Author(s):  
Dong Hyong Lee ◽  
Jeong Won Seo ◽  
Seok Jin Kwon ◽  
Ha Young Choi
Keyword(s):  
Numerical Analysis ◽  
Finite Elements ◽  
Boundary Conditions ◽  
Rolling Contact ◽  
Finite Elements Method ◽  
Vehicle Speed ◽  
Two Dimensional ◽  
Contact Wear ◽  
Rail Wear ◽  
Finite Elements Model

A method to simulate rolling contact wear in a rail surface was developed using the finite elements method and numerical analysis. A two-dimensional finite elements model was used in order to reduce the calculation time and boundary conditions to prevent excessive deformation of a wheel and a rail were applied. A numerical analysis of rail wear at rolling contact was predicted using the Archards equation. In addition, the characteristics of rail wear with the increasing speed of vehicle were analyzed. Results show that there was not a large difference in the depths of wear on the rail head with increasing vehicle speed, but the wear on the rail gauge corner increased with increasing vehicle speed.

scholarly journals Self-regulating electric heater based on elastomer, modified with multilayer carbon nanotubes

2018 ◽  
Vol 80 (3) ◽  
pp. 341-345 ◽  
Author(s):  
V. S. Yagubov ◽  
A. V. Shchegolkov
Keyword(s):  
Carbon Nanotubes ◽  
Temperature Field ◽  
Supply Voltage ◽  
Electric Heating ◽  
Heating Element ◽  
Electric Heater ◽  
Heater Surface ◽  
Electrically Conductive ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The review of modern approaches to the development of electric heating materials makes it possible to conclude that the studies of electrically conductive composites are based on using elastomers modified with nanoscale carbon materials. In the manufacturing of electric heaters, temperature self-regulation is the main property that increases their characteristics. However, researchers engaged in studying such heaters, face difficulties associated with the magnitude of supply voltage and power. In this regard, the tasks of the present work were as follows: to study the modifier characteristics for nanomodified heaters, and to select a modifier that is best dispersed in the elastomer, which will ensure the maximum magnitude of the supply voltage and the high value of the specific power of the heater. To develop an electric heater, silicone rubber modified with carbon nanotubes was used as an elastomer. The method for manufacturing the heating element nanomodified material was described. Multi-walled carbon nanotubes synthesized through the CVD method were employed as an electrically conductive modifier. Before modifying the elastomer, the carbon nanotubes were processed in a mill at a rotational speed of working blades of 25,000 rpm. Then, the nanotubes were thermally treated in a furnace until the temperature of 110 °C was reached. After that, the nanotubes and the elastomer were mixed using a BRABENDER mixer, followed by pressing and obtaining plates of the electric heating material. To ensure contact between the heater and the power source, aluminum foil, inserted into the punches before pressing, was used. The electrical conductivity of the elastic heater nanomodified material was studied using a setup (facility) constructed especially for that purpose. Based on the results obtained, a conclusion can be made on the expediency of using different multi-walled carbon nanotubes as elastomer modifiers, which form electrically conductive networks inside the elastomer and are capable of releasing heat when connected to an electrical voltage source. Employing a non-contact method of measuring the temperature field on the electric heater surface, thermograms were recorded. It was found that the temperature field is uniformly distributed on the heater surface and is stabilized at a certain time after achieving a thermal balance with the environment. From the data obtained, it can be concluded that the heating element connected to an alternating current network with a voltage of 220 V is efficient.

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