Direct observation of three-dimensional transient temperature distribution in SiC Schottky barrier diode under operation by optical-interference contactless thermometry (OICT) imaging

2022 ◽  
Author(s):  
Keiya Fujimoto ◽  
Hiroaki Hanafusa ◽  
Takuma Sato ◽  
Seiichiro HIGASHI
Keyword(s):  
Temperature Distribution ◽  
Schottky Barrier ◽  
Hot Spot ◽  
Local Heating ◽  
Three Dimensional ◽  
Schottky Barrier Diode ◽  
Transient Temperature ◽  
Optical Interference ◽  
Transient Temperature Distribution ◽  
Heating And Cooling

Abstract We have developed optical-interference contactless thermometry (OICT) imaging technique to visualize three-dimensional transient temperature distribution in 4H-SiC Schottky barrier diode (SBD) under operation. When a 1 ms forward pulse bias was applied, clear variation of optical interference fringes induced by self-heating and cooling were observed. Thermal diffusion and optical analysis revealed three-dimensional temperature distribution with high spatial (≤ 10 μm) and temporal (≤ 100 μs) resolutions. A hot spot that signals breakdown of the SBD was successfully captured as an anormal interference, which indicated a local heating to a temperature as high as 805 K at the time of failure.

Thermal Engineering Analysis of Rubber Vulcanization and Tread Temperatures During Severe Sliding of a Tire

1999 ◽  
Vol 27 (1) ◽  
pp. 22-47 ◽  
Author(s):  
H. Sakai ◽  
K. Araki
Keyword(s):  
Temperature Distribution ◽  
Chemical Reaction ◽  
Sliding Friction ◽  
Rolling Resistance ◽  
Temperature History ◽  
Thermal Engineering ◽  
Transient Temperature ◽  
Engineering Analysis ◽  
Transient Temperature Distribution ◽  
Heating And Cooling

Abstract Tire skid marks at the scene of an accident are often used as evidence and are a very important phenomenon. However, the mechanism of this complex phenomenon has not yet been fully examined. Tires are manufactured by a chemical reaction in which rubber molecules are combined into a network structure during a process called vulcanization, in which the tire is heated in a mold. The transient temperature distribution is important in determining the state of vulcanization, but the analysis is very difficult. We treat the tire tread as a rubber slab to estimate the temperature history during heating and cooling. Then we calculate the vulcanization index using Arrhenius's equation, assuming that the rate of chemical reaction approximately doubles as the temperature increases by 10° C. Finally, we calculate the transient temperature distribution of the tread due to the heat generated by internal friction (rolling resistance of the tire), and the heat generated by sliding friction under conditions of severe cornering and braking. We investigate a criterion for modeling the occurrence of tire skid marks, assuming that skid marks are caused by exceeding the softening temperatures of the rubber and asphalt.

A Study on the Three-Dimensional Analysis of the Transient Temperature Distribution in Gas Tungsten Arc Welding

1987 ◽  
Vol 201 (3) ◽  
pp. 149-156 ◽  
Author(s):  
S-J Na ◽  
S-Y Lee
Keyword(s):  
Temperature Distribution ◽  
Heat Flow ◽  
Three Dimensional ◽  
Gta Welding ◽  
Solid Metal ◽  
Transient Temperature ◽  
Solution Domain ◽  
Gas Tungsten Arc ◽  
Transient Temperature Distribution ◽  
Metal Boundary

The transient temperature distribution in the gas tungsten arc (GTA) welding process was analysed by employing a three-dimensional finite element model. In the formulation, the solution domain which moves with the welding heat source was introduced to minimize the number of elements, and consequently the computation time of the three-dimensional program. Since the moving solution domain is small compared with the real weld structure, there are two kinds of boundaries, namely, solid metal-atmosphere boundary and solid metalsolid metal boundary. The heat loss through the solid metal-solid metal boundary was considered through a conduction heat flow and the heat flow through the solid metal-atmosphere boundary through a convection heat flow. As the solution domain moves with the progress of welding, new boundary conditions and new elements were generated in front of the heat source, while some elements disappeared in the rear of it. The initial temperature distribution of the new elements was determined by considering the continuous temperature gradient. To verify the numerical analysis, GTA welding experiments were performed on a medium-carbon steel and the isothermal lines examined. The transient isothermal lines of fusion and heat affected zone boundaries obtained numerically and experimentally were in good agreement. Thus, with the small moving solution domain the change of the fusion zone shape in long welds can be easily analysed, so that, for example, the transient melting characteristics at the start of welding in automatic welding can be effectively simulated for the process optimization.

A photothermoelastic investigation of transient thermal stresses in wing ribs

1972 ◽  
Vol 7 (2) ◽  
pp. 117-124 ◽  
Author(s):  
E Matsumoto ◽  
S Sumi ◽  
T Sekiya
Keyword(s):  
Temperature Distribution ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Composite Model ◽  
New Technique ◽  
Transient Temperature ◽  
Transient Temperature Distribution ◽  
Transient Thermal

The photothermoelastic method of refrigeration has been used to study the problem of a long beam under transient temperature distribution and good correlation with the theoretical values has been obtained. The new technique for three-dimensional photothermoelasticity, which uses a composite model made of photoelastically sensitive and insensitive materials, is suggested for the analysis of idealized wing-rib structures.

Boundary Condition Design to Heat a Moving Object at Uniform Transient Temperature Using Inverse Formulation

2004 ◽  
Vol 126 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Hakan Ertu¨rk ◽  
Ofodike A. Ezekoye ◽  
John R. Howell
Keyword(s):  
Boundary Condition ◽  
Temperature Distribution ◽  
Design Problem ◽  
Manufacturing Industry ◽  
Three Dimensional ◽  
Chemical Deposition ◽  
Iterative Solution ◽  
Conveyor Belt ◽  
Temperature History ◽  
Transient Temperature

The boundary condition design of a three-dimensional furnace that heats an object moving along a conveyor belt of an assembly line is considered. A furnace of this type can be used by the manufacturing industry for applications such as industrial baking, curing of paint, annealing or manufacturing through chemical deposition. The object that is to be heated moves along the furnace as it is heated following a specified temperature history. The spatial temperature distribution on the object is kept isothermal through the whole process. The temperature distribution of the heaters of the furnace should be changed as the object moves so that the specified temperature history can be satisfied. The design problem is transient where a series of inverse problems are solved. The process furnace considered is in the shape of a rectangular tunnel where the heaters are located on the top and the design object moves along the bottom. The inverse design approach is used for the solution, which is advantageous over a traditional trial-and-error solution where an iterative solution is required for every position as the object moves. The inverse formulation of the design problem is ill-posed and involves a set of Fredholm equations of the first kind. The use of advanced solvers that are able to regularize the resulting system is essential. These include the conjugate gradient method, the truncated singular value decomposition or Tikhonov regularization, rather than an ordinary solver, like Gauss-Seidel or Gauss elimination.

Measurement of Transient Temperature Distribution at Anode Surface After Current Zero in Vacuum Interrupter

2021 ◽  
Vol 141 (11) ◽  
pp. 712-717
Author(s):  
Akira Daibo ◽  
Yoshimitsu Niwa ◽  
Naoki Asari ◽  
Wataru Sakaguchi ◽  
Yo Sasaki ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Anode Surface ◽  
Transient Temperature ◽  
Vacuum Interrupter ◽  
Transient Temperature Distribution ◽  
Current Zero
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