scholarly journals Mathematical modeling of heat-trapping properties of a developed radiator surface in mechanical engineering

2021 ◽  
Vol 273 ◽  
pp. 07018
Author(s):  
Nikolay Chernov ◽  
Alexander Palii ◽  
Larisa Tolmacheva ◽  
Konstantin Tomilin ◽  
Mikhail Kritskiy
Keyword(s):  
Thermal Field ◽  
Electronic Devices ◽  
Complex Problem ◽  
Heat Extraction ◽  
Program System ◽  
Element Analysis ◽  
Physical Volume ◽  
Extended Surfaces ◽  
Reliability Of Operation ◽  
A Current

In this work the research of heat-removing properties of areas of extended surfaces, for example, of finned and needle radiators for assessment of efficiency of distribution of a thermal field and heat extraction is described. Also the description of the carried-out computational modeling is provided in the Fluent processor of universal program system of the final and element analysis Ansys. The relevance of the selected subject is confirmed by the fact that one of the most important and difficult tasks arising when developing the electronic equipment is a withdrawal of heat generated by it. At a current steady trend in reduction of dimensions of electronic devices this problem does not disappear, and opposite, becomes more and more sharp, and that is stronger, than device high power less its physical volume, and not only the efficiency of heat extraction, but also dimensions and, of course, reliability of operation of electronic devices depends on constructions of heat-removing elements. In work the conclusion is drawn that for a solution of a complex problem of assessment of efficiency of the heat sink for the purpose of decrease in temperature of heatterminated element, it is necessary to use electrothermal analogy.

scholarly journals A widely adaptable analytical method for thermal analysis of flexible electronics with complex heat source structures

2019 ◽  
Vol 475 (2228) ◽  
pp. 20190402 ◽  
Author(s):  
Yafei Yin ◽  
Min Li ◽  
Wei Yuan ◽  
Xiaolian Chen ◽  
Yuhang Li
Keyword(s):  
Heat Source ◽  
Thermal Management ◽  
Flexible Electronics ◽  
Analytical Method ◽  
Thermal Field ◽  
Complex Shape ◽  
Source Region ◽  
Electronic Devices ◽  
Crucial Issue ◽  
Element Analysis

Flexible electronics, as a relatively new category of device, exhibit prodigious potential in many applications, especially in bio-integrated fields. It is critical to understand that thermal management of certain kinds of exothermic flexible electronics is a crucial issue, whether to avoid or to take advantage of the excessive temperature. A widely adaptable analytical method, validated by finite-element analysis and experiments, is conducted to investigate the thermal properties of exothermic flexible electronics with a heat source in complex shape or complex array layout. The main theoretical strategy to obtain the thermal field is through an integral along the complex curve source region. The results predicted by the analytical model enable accurate control of temperature and heat flow in the flexible electronics, which may help in the design and fabrication of flexible electronic devices in the future.

Nitrogen-Doped Mesoporous Carbon Derived from Polyaniline

2014 ◽  
Vol 926-930 ◽  
pp. 379-382
Author(s):  
De Yi Zhang ◽  
Li Wen Zheng ◽  
Long Yan Lei
Keyword(s):  
Mesoporous Carbon ◽  
Electronic Devices ◽  
Ordered Mesoporous Carbon ◽  
Additional Contribution ◽  
Electrochemical Capacitance ◽  
Supercapacitive Performance ◽  
Nitrogen Doped ◽  
Ordered Mesoporous ◽  
Capacitance Performance ◽  
A Current

In this paper, we demonstrate the successful fabrication of nitrogen doped ordered mesoporous carbon (PNOMC) materials using polyaniline as precursor. The synthesized PNOMC material exhibits enhanced supercapacitive performance due to the additional contribution from pseudo-capacitance originating from incorporation of nitrogen into the framework of carbon materials. Although the specific surface area of ​​the material is not high (386.2 m2/g), the specific capacitance is as high as the 271 F/g at a current density of 1A/g. The fabrication of nitrogen-doped ordered mesoporous carbon with enhanced electrochemical capacitance performance provides a viable route to promote its applications in electronic devices.

scholarly journals Simulation and Analysis of Fluid-Solid Coupling of Wave Impact Sandcastle Based on COMSOL

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Zhen Ouyang ◽  
Ke Wang ◽  
Zihao Yu ◽  
Kaikai Xu ◽  
Qianyu Zhao ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Simulation Analysis ◽  
Coupling Model ◽  
Complex Problem ◽  
Wave Impact ◽  
Element Analysis ◽  
Quantitative Calculation ◽  
The Finite Element Analysis ◽  
The Impact

It is a complex problem to study the interaction between sand castle and flowing water, which needs to consider the complexity of seawater flow and the stress of sand castle structure. The authors use the fluid-solid coupling model to establish the connection between the fluid field and the structural mechanical field, and use the finite element analysis to complete the simulation modeling of the transient process of wave impact and sandcastle foundation deformation. This paper analyzes the stress and the first principal strain of the sand castle foundation in the direction of flow velocity when the sand castle foundation is hit by waves, as a method to judge the strength of the sand castle.The best shape: the boundary value of sand castle collapse caused by strain have been determined, so as to obtain the maximum stress that a sand castle foundation can bear before collapse, which makes it possible to use the fatigue strength calculation theory of sand castle solid to carry out the quantitative calculation of sand castle durability. At the same time, the impact of waves is abstracted as wave motion equation. Finally, the finite element analysis technology is adopted to calculate the main strain of sandcastles of different shapes under the impact of the same wave, and through the comparison of the main strain, the authors get the sandcastle shape with the strongest anti-wave impact ability, which is the eccentric circular platform body.Affected by rain: the authors considered the effect of rainwater infiltration on the sandcastle's stress, and simplified the process of rain as a continuous and uniform infiltration of rain into the sandcastle's surface. The rain changes the gravity of the sand on the castle's surface. Simulation analysis is adopted to calculate the surface stress of sand castle with different degree of water seepage and different geometry. By comparison, it has been found that the smooth cone is more able to withstand the infiltration of rain without collapse. 

Placement Optimization for Thermal Performance of Embedded Power Chip Microwave Modules Using BP-GA

2011 ◽  
Vol 189-193 ◽  
pp. 639-642
Author(s):  
Sheng Zhang ◽  
Zhao Hua Wu ◽  
Hong Yan Huang ◽  
Pin Chen ◽  
Tang Wen Bi
Keyword(s):  
Finite Element Analysis ◽  
Temperature Field ◽  
Thermal Field ◽  
Thermal Design ◽  
Internal Temperature ◽  
Element Analysis ◽  
Thermal Distribution ◽  
Placement Optimization ◽  
Field Distributions ◽  
Embedded Power

In the thermal design of Embedded Power Chip Microwave Modules, the placement of chips on substrate has a significant effect on internal temperature field, thus, influence the reliability of the modules. In this paper, Based on BP-GA, the optimization for chips placement of EPCM is achieved by corresponding optimization program. To demonstrate the effectiveness of the results, ANSYS, finite element analysis (FEA) is carried out to assess the thermal field distribution of the optimization for chips placement. The result shows that the thermal field distributions of the optimization are consistent with the FEA results. The internal highest temperature of the initial placements is 90.369°C. After optimization, the internal highest temperature is 86.128°C, the highest temperature be reduced more than 5°C. It can effectively deal with the problem about optimize the thermal placement of EPCM chips, and improves the internal thermal distribution.

scholarly journals Progress in Cooling Nanoelectronic Devices to Ultra-Low Temperatures

2020 ◽  
Vol 201 (5-6) ◽  
pp. 772-802 ◽  
Author(s):  
A. T. Jones ◽  
C. P. Scheller ◽  
J. R. Prance ◽  
Y. B. Kalyoncu ◽  
D. M. Zumbühl ◽  
...  
Keyword(s):  
State Of The Art ◽  
Electronic Devices ◽  
Bulk Materials ◽  
Nanoelectronic Devices ◽  
Current State ◽  
Physical Effects ◽  
On Chip ◽  
Nanoscale Physics ◽  
A Current ◽  
Made In

AbstractHere we review recent progress in cooling micro-/nanoelectronic devices significantly below 10 mK. A number of groups worldwide are working to produce sub-millikelvin on-chip electron temperatures, motivated by the possibility of observing new physical effects and improving the performance of quantum technologies, sensors and metrological standards. The challenge is a longstanding one, with the lowest reported on-chip electron temperature having remained around 4 mK for more than 15 years. This is despite the fact that microkelvin temperatures have been accessible in bulk materials since the mid-twentieth century. In this review, we describe progress made in the last 5 years using new cooling techniques. Developments have been driven by improvements in the understanding of nanoscale physics, material properties and heat flow in electronic devices at ultralow temperatures and have involved collaboration between universities and institutes, physicists and engineers. We hope that this review will serve as a summary of the current state of the art and provide a roadmap for future developments. We focus on techniques that have shown, in experiment, the potential to reach sub-millikelvin electron temperatures. In particular, we focus on on-chip demagnetisation refrigeration. Multiple groups have used this technique to reach temperatures around 1 mK, with a current lowest temperature below 0.5 mK.

Study on the Thermal Field Distribution of Steel Claws for Anode in Aluminium Electrolysis Cell

2015 ◽  
Vol 1120-1121 ◽  
pp. 1089-1092
Author(s):  
Qing Dong Qin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Field Distribution ◽  
Thermal Field ◽  
Voltage Drop ◽  
The Other ◽  
Electrolysis Cell ◽  
Aluminium Electrolysis ◽  
Element Analysis ◽  
Anode Carbon

The electricity consuming of aluminium electrolysis cell is affected by the voltage drop of anode steel claws during the aluminium electrolysis course. The resistivity of anode steel claws is affected by the temperature. In the present study, the thermal field distribution of anode steel claws was studied by finite element analysis. The results show that the thermal energy of anode steel claws come from anode carbon blocks and environment. The temperature of steel claws less than 1/3 height is affected by anode carbon blocks, and the other part is affected by surrounding temperature. According the results, the principle of the new anode steel claw design is proposed.

Analysis of Novel Packaging Techniques for High Power Electronics in SiC

2007 ◽  
Vol 556-557 ◽  
pp. 971-974
Author(s):  
S.J. Rashid ◽  
C. Mark Johnson ◽  
F. Udrea ◽  
Andrej Mihaila ◽  
G. Amaratunga ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Copper Substrate ◽  
Mechanical Analysis ◽  
Element Analysis ◽  
Effective Resistivity ◽  
Assembly Result ◽  
Full Load Operation ◽  
Expansion Coefficients ◽  
Device Operation ◽  
A Current

A novel high temperature wire bondless packaging technique is numerically investigated in this paper. Extraction of device effective resistivity with temperature from numerical characteristics of 1.2kV 4H-SiC MOSFETs at a current density of 400A/cm2 have demonstrated a T−2 temperature dependence. Electro-thermal finite element analysis (FEA) of 1.2kV 4H-SiC MOSFETs sandwiched between two etched direct-bonded-copper substrate tiles has been performed. The thermal resistance of the ceramic sandwich package shows a 75% reduction in thermal resistance compared to conventional wire bonded assemblies. Mechanical analysis of the assembly has been used to investigate the residual stresses in the SiC dies at room temperature, which are then alleviated at higher temperatures during device operation. Mismatch of the expansion coefficients of the auxiliary materials in the assembly result in elevated stresses at full load operation, however these are well below the tensile strength of the respective materials and hence do not compromise the mechanical integrity of the package.

Nano-Hydroxyapatite Coatings on Titanium Substrates. Finite Element Analysis of Process and Experimental Plasma Thermal Sprayed Coatings

2007 ◽  
Vol 361-363 ◽  
pp. 745-748 ◽  
Author(s):  
Helene Citterio-Bigot ◽  
S. Jakani ◽  
Abdelilah Benmarouane ◽  
Pierre Millet ◽  
Alain Lodini
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Field ◽  
Thermal Spraying ◽  
Average Crystallite Size ◽  
Nucleation Site ◽  
Layer By Layer ◽  
Element Analysis ◽  
Hydroxyapatite Coatings ◽  
Crystallite Sizes

The aim of this study was to create a nano-structured coating using Plasma Thermal Spraying (PTS). This process consists in introducing pre-agglomerated nanosized particles in a high-temperature and high-velocity gas jet and projected them onto the substrate to form, layer by layer, a nanostructured coating. In order to retain nanometer grain sizes in the deposited coating through specific PTS technologies, a thermal field and velocity distribution in the plasma jet are analytically calculated. A finite element analysis is employed to calculate the thermal field evolution inside the agglomerated particles and the thermal induced internal stress distribution is determined. The parameters determined by the theoretical analysis are used for experimental coatings. The average crystallite size of nano-hydroxyapatite powder was 90nm. After deposit via Plasma Thermal Spraying (PTS) process and followed by a 2 hours heat treatment to reduce amorphous fraction, the experimental deposited coating shows that it retains the nanometer crystallite sizes. The substructure of nanocrystals was evaluated at about 120nm in size. Such a nanocoating may play the role of nucleation site to bone, allowing a faster stabilization of the implant.

Sheet Metal Forming Process Design Rules Development

2011 ◽  
Vol 473 ◽  
pp. 765-772
Author(s):  
Antonio del Prete ◽  
Gabriele Papadia ◽  
Teresa Primo
Keyword(s):  
Process Design ◽  
Process Variable ◽  
Complex Problem ◽  
Industrial Test ◽  
Thickness Ratio ◽  
Die Design ◽  
Design Development ◽  
Forming Process ◽  
Element Analysis ◽  
Constitutive Material

Finite element analysis (FEA) is a powerful tool to evaluate the formability of stamping parts during process and die design development procedures. However, in order to achieve good product quality and process reliability, FEA application has to be performed many times exploring different process parameters combinations. Meanwhile, it is very difficult to perform an exhaustive process design definition when many parameters play a fundamental role to define such a complex problem. So, under the needs of reduction in: design time, development cost and parts weight, there is an urgent need to develop and apply more efficient methods in order to improve the current design procedures. For a generic component it is clear how its shape, among several parameters, has a direct influence on its feasibility. Starting from this assumption, the authors have developed a new approach grouping components upon their shapes analyzing component formability within a given “component family”. Nowadays, it exists only a process designer “sensitivity” that produces a ranking upon shape/feasibility ratio. Having as reference industrial test cases, the authors have defined appropriate shape parameters in order to have dimensionless coefficients representative for the given geometries. In particular, the components have been classified using a parameters set defining similarity families: related to geometrical aspects and to constitutive material. From the geometrical point of view the following parameters have been defined: family name, shape factor, punch radius-thickness ratio, die radius-thickness ratio, while for the constitutive material a code has been defined. FEA has been extensively used in order to: define, investigate and validate each shape parameter with a proper comparison to the macro feasibility of the chosen component geometry. The feasibility configuration definition, for a given shape, has been made through an appropriate study of the influence of each process variable on the properly process performances.

Numerical Modeling of Thermal Field Distribution during Friction Stir Welding (FSW) of Dissimilar Materials

2016 ◽  
Vol 254 ◽  
pp. 261-266
Author(s):  
Bogdan Radu ◽  
Cosmin Codrean ◽  
Radu Cojocaru ◽  
Cristian Ciucă
Keyword(s):  
Numerical Modeling ◽  
Friction Stir Welding ◽  
Solid State ◽  
Thermal Field ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Dissimilar Joints ◽  
Element Analysis ◽  
Friction Stir ◽  
The Cost

Friction Stir Welding (FSW) is an innovative solid state welding process, relatively new in industry, which allow welding of two or more materials which have very different properties, particularly thermal properties as fusion temperature, thermal expansion coefficient, specific heat and thermal conduction and have a predisposition to form intermetallic brittle phases, neither one of the components to be weld reach to the melting point. Being a solid state welding process temperature field is very important for the quality of the welded joint, and a lot of researches focused on this topic. This paper presents some results in modeling and estimation of thermal field developed during FSW of dissimilar joints, using Finite Element Analysis. Numerical modeling of thermal field allows engineers to predict, in advance, the evolution of temperature and to estimate the behavior of the welded materials during the welding process. This will reduce significantly the time and number of experiments that have to be carried out, in the process of establishing a good FSW technology, as well as reducing significantly the cost of the tests.

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