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Currently the controlled release of drugs in specific areas is of great importance for the treatment of diseases such as cancer, Parkinson, Alzheimer and others. This project works with focused ultrasound (HIFU) in rats, more specifically in the application of HIFU in a specific area of the brain called the substantia nigra, in order to generate opening in the membrane of this area called blood-brain...
In order to improve the heat dissipation performance of IGBT module, a new type of structure unit for Three-dimensional IGBT module packaging which can implement double-sided cooling has been built. In view of the traditional single-sided cooling structure unit of IGBT module and the new type of Three-dimensional structure unit in double-sided cooling IGBT module, a corresponding mathematical model...
In order to improve the heat dissipation performance of IGBT module, a new type of structure unit for Three-dimensional IGBT module packaging which can implement double-sided cooling has been built. In view of the traditional single-sided cooling structure unit of IGBT module and the new type of Three-dimensional structure unit in double-sided cooling IGBT module, a corresponding mathematical model...
Use of underground power distribution has grown significantly over the years with the rapid increase in demand for electric energy and the trend for large infra-structures and vast expansion of highly-populated metropolitan areas. Such approximations and assumptions lead to inaccuracies in the calculations and often force cable engineers to use un-necessarily large safety factors and overly conservative...
This paper presents the analysis of temperature rise on PCB. Numerical solutions using Galerkin approach that is one of Finite Element Method (FEM) was used to study and analyze the temperature rise on PCB. Then, an algorithm has been developed using MATLAB. The PCB with four different width of copper is supplied with different range of direct current (DC) from 0.5 to 5 Amperes to capture the data...
In this paper, the shape identification method in the Inverse Heat Conduction Problems (IHCP) is applied to estimate the shape of frost on a refrigeration tube. The inverse algorithm consists of direct, inverse analysis and gradient-based optimization method. The direct analysis used Finite Element Method (FEM) in an unstructured grid system to solve the direct heat conduction problem. The inverse...
The maximum principal stress, von Mises equivalent stress, equivalent creep strain in dissimilar welded joints between martensitic heat-resistant steel (T91) and bainitic heat-resistant steel (G102) are simulated by FEM under the conditions of 833K and inner pressure of 28MPa. The results show that the maximum principal stress and von Mises equivalent stress are quit high in the vicinity of weld/G102...
The ratio of the temperature gradient at solidification front to the solidification rate of solid-liquid interface plays a great role for columnar grain growth. Transient temperature fields of directional solidification of Al-Ni-Co-Ti alloys were studied based FEM. The effect of molten steel pouring temperature, heat flux and mould temperature on the ratio was analyzed. The results show that molten...
To figure out the temperature distribution laws of laminated damping apparatus, a method based on heat flow distribution and superposition methods is proposed to solve the steady state temperature distribution of the laminated damping apparatus with nonuniform generation. Heat flow and temperature distribution formulas of the apparatus are derived. A numerical example is performed to verify the correction...
In this paper we analyse numerically and experimentally the quench behavior of Cu-stabilized second-generation high temperature superconducting (2G HTS) wires at self-field and in adiabatic conditions. The electric field profiles along the superconductor after applying an energy pulse to the conductor have been obtained together with the parameters characterizing the quench: minimum quench energy...
This paper presents thermo-mechanical investigation results of a reconfigurable wafer-scale integrated circuit, the WaferIC™, dedicated to electronic systems prototyping. The proposed approach carefully selects materials combined with an active cooling mechanism to avoid critical localized thermal peaks and associated large thermal stresses. The performance of the approach was evaluated and tested...
A coupled electro-thermal-mechanical analysis of partially insulated field-effect transistors (PiFETs) is performed using the proposed hybrid nonlinear finite element method (FEM) with temperature-dependent parameters rigorously treated. The two major structures of PiFET, namely the partially insulating oxide (PiOX) under the drain and source (PUSD) and partially insulating oxide under the channel...
The work principles, failure modes, material selection, heat treatment process of rotary forging dies are researched in this paper. When working, the dies not only bears great pressure and long time high temperature, but also bears alternating stress caused by repeated heating and cooling which can easily lead to heat fatigue crack. Selecting proper die material and using appropriate heat treatment...
Elastic-plastic nonlinear finite element method(FEM) with large deformation and contact is applied to establish FE models respectively based on various process such as roll assembly, roll grinding and heating and pressing deformation in casting. Then the force and deformation are analyzed to get the roll profile curve in casting. The calculation results are verified with strip section shape, and the...
Aiming at complexity of hydrogeological conditions of coal mine, this paper brought forward the improved chaos-genetic optimization method based on the chaos optimization method and genetic algorithm method. Using the optimization method, this paper have carried out the back analysis of earth temperature field of coal mine, then predicted the earth temperature field using the parameters of the back...
Permanent magnet brushless DC motors used in aerospace generally have numerous qualities such as light weight, small size, and high efficiency. This means that the thermal design of those motors is very serious. In order to obtain an accurate thermal field simulation of a permanent magnet brushless DC motor, both electromagnetic and thermal fields have to be calculated in a coupled simulation. In...
The 3-D transient temperature field in selective laser sintering of copper powder were simulated by ANSYS finite element software. The moving Gauss heat resource is achieved by ANSYS Parametric Design Language (APDL). The results show that when the power is constant, with the decrease of the scanning speed, the heat is easier to concentrate, and the temperature is higher. The depth and width of molten...
The paper presents the design and construction of new SMT power inductors that allow for high components packaging density and automated manufacturing of power converters. The inductors are double sided SMDs with a uniform profile (14mm), reduced packaging (i.e. no coil former) and enhanced thermal properties. The inductor is implemented with drum and shield magnetic core parts. The thermal behaviour...
An analysis of low frequency properties (f below 10 Hz) in a single-junction thermal converter (SJTC) have been performed by finite element method (FEM). Thermal radiation and Thomson effect is taken into considerations in this calculation. The result of the calculation is in agreement with that of the measurement.
Dual mechanical port machine (DMP) - a kind of continuous electrical variable transmission, is a very competitive alternative for vulnerable constant speed-ratio mechanical gearbox in high capacity wind power generation system. As the inner rotor is surrounded by the stator and the outer rotor, the DMP machine suffers from PM demagnetization and insulation failure under severe thermal condition. To...
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