Qualitative Geometric Reasoning for Thermal Design Evaluation of Die Casting

2000 ◽  
Author(s):  
Yuming Ma ◽  
Adham Ragab ◽  
Khalil Kabiri ◽  
R. Allen Miller
Keyword(s):  
Heat Flow ◽  
Thermal Characteristics ◽  
Main Idea ◽  
Volume Visualization ◽  
Thermal Control ◽  
Thermal Design ◽  
Geometric Reasoning ◽  
Design Stage ◽  
Prototype System ◽  
Voxel Model

Abstract This paper discusses a qualitative geometric reasoning method which approximately evaluates the equilibrium thermal characteristics of die-castings and dies at the conceptual design stage. The main idea is to apply circuit analog of heat flow on a voxel model and build the heat flow network for the die. An approximate temperature distribution on the die is then obtained by geometric reasoning and thermal resistance computation on voxel model. The resulting temperature field of the die is visualized using volume visualization techniques, and heat converging regions (hot spots) can be identified from the pattern. Thermal control features can then be placed according to the location of the heat converging regions and part thickness. A prototype system has been implemented on Microsoft Windows-NT platform.

Structure Design for Heat Sink Based on Thermal Analysis

2011 ◽  
Vol 80-81 ◽  
pp. 767-773
Author(s):  
Hai Gang Sun ◽  
Yong Zhou
Keyword(s):  
Thermal Analysis ◽  
Thermal Performance ◽  
Heat Sink ◽  
Cfd Simulation ◽  
Thermal Control ◽  
Structure Design ◽  
Thermal Design ◽  
Structure Parameters ◽  
Igbt Module ◽  
Key Factor

Thermal design and the working temperature control have been a key factor in the design of electronic devices and system. In this paper, a sort of heat sink collocated with high-power IGBT module, which is commonly used in car-carrying motor control system, is designed based on thermal analysis by means of CFD simulation and computer-aided analyzing, also the influence relations of structure parameters with thermal performance are studied. With thermal control as the overall design objective, structure parameters of heat sink are determined according to the obtained relations. Further, thermal performance of the designed heat sink is simulated and analyzed in CFD software to examine the validity of the design result. In this way, a method of thermal analyzing and structure parameter design for heat sink, which is proved as an efficacious approach, is introduced and can be used to thermal design and analysis for similar products.

An Insight into the Features of the OAO-C Thermal Design

1973 ◽  
Vol 95 (4) ◽  
pp. 1039-1047 ◽  
Author(s):  
H. Fine ◽  
J. Quadrini ◽  
S. Ollendorf
Keyword(s):  
Thermal Control ◽  
Astronomical Observatory ◽  
Thermal Design ◽  
Test Bed ◽  
Large Space ◽  
Flight Data ◽  
The Earth ◽  
Ground Test ◽  
Earth Observation Satellite ◽  
Insight Into

The Orbiting Astronomical Observatory (OAO)-C was successfully launched into 400-nautical mile circular orbit on August 21, 1972. For this spacecraft, a unique sensitivity approach to the thermal design was developed which resulted in a predictal design—the merits of which should be considered for application on future spacecra. The OAO-C is also serving as a test bed for the evaluation of thermal control hardware. To provide flight data for space program applications, experiments for a new coating and four different heat pipe designs are on this spacecraft. The data derived from OAO-C will be extremely valuable for such future programs as the Large Space Telescope (LST) and the Earth Observation Satellite (EOS). This paper will describe the detailed of the sensitivity design approach and thermal control hardware. For all aspects discussed, a comparison of pertinent analysis, ground test data, and flight data [1] will be given.

Integrating an Electronics Component Database Into a Thermal Design Tool

2009 ◽  
Author(s):  
Patrick Loney
Keyword(s):  
Human Error ◽  
Thermal Characteristics ◽  
Design Tool ◽  
Thermal Design ◽  
Junction Temperature ◽  
Analysis Tool ◽  
Resistance Performance ◽  
Business Sectors ◽  
Component Database ◽  
Pin Configuration

When developing a thermal model of a highly populated electronics board, a significant amount of time and effort is needed to track the thermal characteristics of all the dissipating components. In business sectors where multiple boards are thermally designed and analyzed each year, developing a components database and integrating it into the analysis tool will save time and ensure that consistent values are used in every design. With an “in tool” component database, multiple advantages are achieved. Once a component is entered into the database, the component information can be accessed in subsequent designs that employ the component. All engineers doing thermal design have access to the database. Once the thermal characteristics of a component are agreed upon, consistency across all boards is maintained. Additionally, values for each component in the database can be automatically brought into the analysis tool. By making a computer program develop the model of the component, human error is removed. The database tracks all major thermal aspects of a component. This includes the maximum junction temperature, Theta JC (case to junction resistance), leg/pin configuration (size, length, number, conductivity), and board to case gap thickness. Optional values can include top side cooling resistance, performance temperature limits, manufacturer, datasheet web address, and even an entry to identify the configuring engineer.

Thermal Characterization of Non-Isolated DC to DC Convertor

2011 ◽  
Author(s):  
Shiladitya Chakravorty ◽  
Bahgat Sammakia ◽  
Varaprasad Calmidi
Keyword(s):  
Power Dissipation ◽  
High Performance ◽  
Field Effect Transistors ◽  
Thermal Characteristics ◽  
Thermal Characterization ◽  
Input Voltage ◽  
Thermal Design ◽  
Power Module ◽  
Improved Performance

Improved performance of semiconductor devices in recent years has resulted in consequent increase in power dissipation. Hence thermal characterization of components becomes important from an overall thermal design perspective of the system. This study looks at a high performance non-isolated point of load power module (a DC to DC converter) meant for advanced computing and server applications. Thermal characteristics of the module were experimentally analyzed by placing the power module on a bare test board (with no insulation) inside a wind tunnel with thermocouples attached to it. There were three devices on this module that dissipate power. There were two FETs (Field Effect Transistors) and an inductor which can be considered as sources. The consolidated power dissipation from the module was calculated by measuring the input voltage and input current while keeping the output voltage and current constant. Temperatures at various points on the module and the test card were recorded for different air flow velocities and overall power dissipation. Subsequently this set up was numerically analyzed using a commercially available computational fluid dynamics (CFD) code with the objective of comparing the results with experimental data previously obtained.

Categorized Application Technology of Numerical Simulation on Electronic Equipment Thermal Design

2009 ◽  
Author(s):  
Yasuyuki Yokono ◽  
Katsumi Hisano ◽  
Kenji Hirohata
Keyword(s):  
Numerical Simulation ◽  
Product Development ◽  
Statistical Approach ◽  
Thermal Design ◽  
Electronic Equipment ◽  
Product Development Process ◽  
Design Stage ◽  
Application Technology ◽  
Simulation Techniques ◽  
Simulation Based

In order to utilize a numerical simulation on a product development for electronic equipment, not only the simulation techniques themselves, but the application technologies of the simulation in the product design, were examined. The design process of electronic equipment was categorized into four stages, which were a concept, a function, a layout and a parameter design. Each design stage consists of a specifying that a human decide the specification for the next stage and a verification whether the specification satisfy the previous stage requirements. The specifying and the verification are conducted over and over again. Numerical simulation is corresponded to the verification and is used to accelerate this iteration instead of experiments. The examples of numerical simulation corresponding to these four verifications were shown in the present paper. There are few examples in last two type of simulation. The progress of the numerical technology for function and concept verification is expected. The product development process requires not only numerical simulation based on physics but also statistical approach.

Specific Heat Capacity Measurement of Al / SiCp Composites by Differential Scanning Calorimeter

2011 ◽  
Vol 264-265 ◽  
pp. 669-674 ◽  
Author(s):  
B. Karthikeyan ◽  
S. Ramanathan ◽  
V. Ramakrishnan
Keyword(s):  
Specific Heat ◽  
Volume Fraction ◽  
Thermal Control ◽  
Stir Casting ◽  
Thermal Design ◽  
Capacity Measurement ◽  
Scanning Calorimetry ◽  
Heat Measurement ◽  
Casting Technique ◽  
Materials Used

Various materials are used to achieve a good “Thermal Control System” (TCS) of spacecraft. The performance of the TCS totally depends upon the thermal behaviour of the materials used in the elements of TCS. The measurements of the thermal properties of materials are fundamental for better understanding of the thermal design. Differential Scanning Calorimetry (DSC) is the most widely used thermal technique for obtaining a wealth of information about a material, especially for the specific heat measurement of a material. Stir casting technique was used to fabricate the 7075 aluminum alloy and 7075 Al / SiCp composites. The heat flow response is recorded as a function of actual sample temperature range from -1000 C to 4000 C. Specific heat characteristics of 7075 Al reinforced with different volume fraction of silicon carbide composites fabricated by stir casting method was analyzed.

Fundamental Study on Thermal Characteristics of Heat Spreaders

2011 ◽  
Author(s):  
Yasushi Koito ◽  
Yusaku Nonaka ◽  
Toshio Tomimura
Keyword(s):  
Thermal Management ◽  
Theoretical Study ◽  
Thermal Characteristics ◽  
Thermal Design ◽  
Design Parameters ◽  
Heat Spreader ◽  
Fundamental Study ◽  
Discharge Characteristics ◽  
Heat Spreaders ◽  
Large Heat

A heat spreader is one of the solutions for thermal management of electronic and photonic systems. By placing the heat spreader between a small heat source and a large heat sink, the heat flux is spread from the former to the latter, resulting in a lower thermal spreading resistance between them. There are many types of heat spreaders known today having different heat transfer modes, shapes and sizes. This paper describes the theoretical study to present the fundamental data for the rational use and thermal design of heat spreaders. Two-dimensional disk-shaped mathematical model of the heat spreader is constructed, and the dimensionless numerical analysis is performed to investigate the thermal spreading characteristics of the heat spreaders. From the numerical results, the temperature distribution and the heat flow inside the heat spreaders are visualized, and then the effects of design parameters are clarified. The discussion is also made on the discharge characteristics of the heat spreaders. Moreover, a simple equation is proposed to evaluate the heat spreaders.

Specific Heat Measurements of Ti6Al4V/Nano SiCp Composite

2017 ◽  
Vol 14 (1) ◽  
pp. 742-746
Author(s):  
S Krishnamohan ◽  
S Ramanathan ◽  
V Ramakrishnan
Keyword(s):  
Heat Capacity ◽  
Weight Ratio ◽  
Thermal Control ◽  
Ti6al4v Alloy ◽  
Thermal Design ◽  
Thermal Method ◽  
Scanning Calorimetry ◽  
Low Weight ◽  
Wide Range ◽  
Materials Used

The elevated strength, low weight ratio and excellent corrosion resistance intrinsic to titanium and its alloys has led to a wide range of successful applications which ensures high levels of unswerving performance in aerospace. The performance of the Thermal Control System extremely depends on the thermal behavior of the materials used in its elements. The measurements of the thermal properties of materials are necessary for better understanding of the thermal design. Differential scanning calorimetry (DSC) is the most extensively used thermal method for finding wealth of information about a material. The heat capacity (Cp) of a material was established quantitatively using DSC. The measurement was made by heating a very small quantity of the Ti6Al4V alloy and Ti6Al4V/Nano SiCp composites. Mechanical alloying (MA) and Powder metallurgy (P/M) techniques were used to fabricate the Ti6Al4V alloy and Ti6Al4V/ nano SiCp composites. The heat flow reaction was recorded as a function of definite sample temperature range from −100 °C to 375 °C. The measurements of the heat capacity of each sample in three runs were recorded by DSC. The heat capacity (Cp) of specimens is reported in this study.

The Microstructure and Thermochromic Properties of La1-XSrXMnO3 Smart Materials

2013 ◽  
Vol 690-693 ◽  
pp. 648-653 ◽  
Author(s):  
Min Xu ◽  
Zhao Hui Fu ◽  
Lin Li ◽  
Jie Bing Wang ◽  
Chun Hua Wu ◽  
...  
Keyword(s):  
Smart Materials ◽  
Thermal Control ◽  
Solid State Reaction Method ◽  
Thermal Design ◽  
Radiative Properties ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Thermal Radiative Properties ◽  
Potential Applications ◽  
Thermochromic Properties

The La1-xSrxMnO3 materials have potential applications in thermal control systems of microsatellites. The microstructure of La1-xSrxMnO3 materials is very sensitive to the compound of Sr incorporated into it. In this paper, preparation process of La1-xSrxMnO3 compounds was explored. Ceramic sintering process combined with a conventional solid state reaction method was used to prepare various components of La1-xSrxMnO3。 Annealing temperature, time and doped ratio were controlled in the experiment. X-ray diffraction and Raman spectroscopy were used to analyze phase structure and crystalline. Thermal radiative properties were measured on a Calorimetric Emissometer at 175K～375K. These investigations reveal that microstructure of La1-xSrxMnO3 compounds are affected by Sr2+doping level(x).Thermal emissivity of La0.825Sr0.175MnO3 materials vary widely from 0.68 to 0.37, which can meet requirement of future space thermal design.

Qualitative modeling and analysis of lateral load resistance in frames

1993 ◽  
Vol 7 (4) ◽  
pp. 239-256 ◽  
Author(s):  
Renate Fruchter ◽  
Helmut Krawinkler ◽  
Kincho H. Law
Keyword(s):  
Qualitative Evaluation ◽  
Evaluation Process ◽  
Load Resistance ◽  
Lateral Load ◽  
Structural Behavior ◽  
Design Stage ◽  
Prototype System ◽  
Qualitative Modeling ◽  
Load Path ◽  
Lateral Load Resistance

This paper discusses a work in progress in the development of computer tools for qualitative modeling analysis and evaluation of conceptual structural designs. In the conceptual design stage the description of a structure is incomplete and imprecise, and does not permit the use of traditional numerical analysis tools. We describe a prototype system, QLRS, for qualitative evaluation of lateral load resistance in frames. The primary goal of the evaluation of structural response is to identify undesirable structural behavior. In QLRS, the evaluation process consists of three basic tasks. (1) identification of the story and structure models comprising the lateral load resisting system. We term this task structural system interpretation. (2) Qualitative analysis of the story and structure models, and approximate evaluation of the story drifts. We term this task structural behavior interpretation. (3) Assessment of the performance of the lateral load resisting system, in which the results of the structural system interpretation and the structural behavior interpretation are compared against the requirements for complete load path and relative story drift. Currently, QLRS is able to reason about load path discontinuities and soft-story behavior problems in 2-D moment resisting frames.

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