Sensitivity of thermal design parameters for space spectral imaging apparatus

2012 ◽  
Vol 20 (6) ◽  
pp. 1208-1217
Author(s):  
郭亮 GUO Liang ◽  
吴清文 WU Qing-wen ◽  
颜昌翔 YAN Chang-xiang
Keyword(s):  
Spectral Imaging ◽  
Thermal Design ◽  
Design Parameters

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.

Construction, performance, and thermal design of plate heat exchangers

2009 ◽  
Vol 223 (3) ◽  
pp. 123-131 ◽  
Author(s):  
M A Mehrabian
Keyword(s):  
Heat Exchangers ◽  
Close Agreement ◽  
Thermal Design ◽  
Design Parameters ◽  
Final Decision ◽  
Process Data ◽  
Design Data ◽  
Plate Heat ◽  
Computer Codes

Much of design data for plate heat exchangers remain proprietary. A step by step methodology for determination of the exchanger size and internal geometry from the knowledge of process data is scarce. Commercial computer codes do not give the user accessibility to mathematical modelling. Engineers do not usually understand the terminology and geometry of these exchangers. This article presents a manual method for thermal design of plate heat exchangers based on physically meaningful estimations, calculations, and comparisons. When there is no close agreement, it may be necessary to change one or more of the design parameters, i.e. channel (passage) velocities, wall temperatures, or corrugation inclination angle. Considerable skill and judgment is required by the thermal design engineer at this stage to decide how the tentative design should be changed to provide a rapid solution. The experienced design engineer is often able to judge on the final decision from the first or second trial designs.

Investigation of a Novel Flat Heat Pipe

2005 ◽  
Vol 127 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Yaxiong Wang ◽  
G. P. Peterson
Keyword(s):  
Heat Pipe ◽  
Heat Transport ◽  
Thermal Design ◽  
Experimental Results ◽  
Design Parameters ◽  
Working Fluid ◽  
Transport Capacity ◽  
Maximum Heat ◽  
Mesh Screen ◽  
Flat Heat Pipe

A novel flat heat pipe has been developed to assist in meeting the high thermal design requirements in high power microelectronics, power converting systems, laptop computers and spacecraft thermal control systems. Two different prototypes, each measuring 152.4 mm by 25.4 mm were constructed and evaluated experimentally. Sintered copper screen mesh was used as the primary wicking structure, in conjunction with a series of parallel wires, which formed liquid arteries. Water was selected as the working fluid. Both experimental and analytical investigations were conducted to examine the maximum heat transport capacity and optimize the design parameters of this particular design. The experimental results indicated that the maximum heat transport capacity and heat flux for Prototype 1, which utilized four layers of 100 mesh screen were 112 W and 17.4W/cm2, respectively, in the horizontal position. For Prototype 2, which utilized six layers of 150 mesh screen, these values were 123 W and 19.1W/cm2, respectively. The experimental results were in good agreement with the theoretical predictions for a mesh compact coefficient of C=1.15.

Developing Bayesian Surrogates for Use in Preliminary Design

2001 ◽  
Author(s):  
Jorge E. Pacheco ◽  
Cristina H. Amon ◽  
Susan Finger
Keyword(s):  
Heat Transfer ◽  
Surrogate Model ◽  
Transfer Problem ◽  
A Priori ◽  
Thermal Design ◽  
Design Parameters ◽  
System Response ◽  
Preliminary Design ◽  
Limited Information ◽  
Few Data

Abstract During the preliminary design stages, designers often have incomplete knowledge about the interactions among design parameters. We are developing a methodology that will enable designers to create models with levels of detail and accuracy that correspond to the current state of the design knowledge. The methodology uses Bayesian surrogate models that are updated sequentially in stages. Thus, designers can create a rough surrogate model when only a few data points are available and then refine the model as the design progresses and more information becomes available. These surrogates represent the system response when limited information is available and when few realizations of experiments or numerical simulations are possible. This paper presents a covariance-based approach for building surrogates in the preliminary design stages when bounds are not available a priori. We test the methodology using an analytical one-dimensional function and a heat transfer problem with an analytical solution, in order to obtain error measurements. We then illustrate the use of the methodology in a thermal design problem for wearable computers. In this problem, the underlying heat transfer phenomena make the system response non-intuitive. The surrogate model enables the designer to understand the relationships among the design parameters in order to specify a system with the desired behavior.

A Scalable Silicon Micro-Reactor for Preferential CO Oxidation With an Integrated Platinum Heater

2005 ◽  
Author(s):  
Amit Dhingra ◽  
Hong G. Im ◽  
Sujit Srinivas ◽  
Erdogan Gulari
Keyword(s):  
Fuel Cell ◽  
Co Oxidation ◽  
Packed Bed ◽  
Critical Issue ◽  
Thermal Design ◽  
Packed Bed Reactor ◽  
Design Parameters ◽  
Reactor Model ◽  
Preferential Co Oxidation ◽  
Micro Reactor

Recent advances in PEM fuel cell systems have demonstrated their role in the production of clean and efficient power. However, due to complexities and safety concerns in the storage and transport of hydrogen, development of on-board fuel processing of hydrocarbon into hydrogen is being considered a critical issue in the success of the fuel cell technology in transportation application. In this paper, a novel concept of scalable silicon micro-reactor with an integrated platinum heater is developed for preferential CO oxidation. The performance of the micro-reactor is assessed and compared to a packed-bed reactor model. Complementary experimental and modeling efforts are made to identify the optimal thermal design parameters. It is demonstrated that the silicon micro-reactors successfully achieves the objectives of scalability without suffering from loss of efficiency due to the mass transfer limitations.

Multidisciplinary Sensitivity Analysis of the Cooling System of a High-Pressure Turbine Blade in the Pre-Design Phase

2021 ◽  
Author(s):  
Barbara Fiedler ◽  
Yannick Muller ◽  
Matthias Voigt ◽  
Ronald Mailach
Keyword(s):  
Mass Flow ◽  
Cooling System ◽  
Mechanical Analysis ◽  
Thermal Design ◽  
Probabilistic Methods ◽  
Cycle Performance ◽  
Design Parameters ◽  
Cooling Systems ◽  
Cooling Air Flow ◽  
Cooling Air

Abstract The engine-cycle performance of jet engines can be improved by more efficient cooling systems, either by reducing the required cooling air or by intensifying the cooling efficiency with the same amount of cooling mass flow. However, the multitude of geometrical design parameters and the strong multidisciplinary aspect of cooling mass flow consumption optimization make designing the cooling systems extremely challenging. Integrating probabilistic methods into the thermal design process enables the automated evaluation of multiple design variants which contributes to the development of more efficient systems. In the present study, the sensitivity of a multi-pass cooling system to geometric variations is investigated. The cooling air flow, solved using a 1D, correlation based flow solver, is iteratively coupled with the 3D-FE thermo-mechanical analysis of the blade. The geometry of the cooling system is varied using the Harmonic-Spline-Deformation parametric, which has been extended to modify the wall thickness enabling to perform a geometrical-holistic analysis. Furthermore, the Elementary-Effects-Method (EEM) and the Monte-Carlo-Simulation (MCS) are compared to identify the most influential parameters and analyze their complex interactions. It is shown that the cooling system’s performance is mostly affected by the shape and position of the first web. Furthermore, MCS proves to be robust towards changes in design space while simultaneously enabling a more detailed analysis of the system behavior compared to EEM.

Thermal Design Correlations for Single- and Two-Phase Flow of R-407C in Meso-Scale Heat Exchangers

2004 ◽  
Author(s):  
Yasir M. Shariff ◽  
T. S. Ravigururajan
Keyword(s):  
Flow Boiling ◽  
Thermal Design ◽  
Design Parameters ◽  
Two Phase ◽  
Channel Diameter ◽  
Experimental Database ◽  
Boiling Flow ◽  
Flow Variables ◽  
Saturated Boiling ◽  
Meso Scale

The paper presents correlation development for an experimental database done on R-407C flow in meso-scale horizontal channels. Single-phase, two-phase subcooled, and two-phase saturated boiling flow correlations were developed. The variables considered in this study including essential design parameters, such as, channel diameter, coils pitch and diameter. For flow variables considered are the Reynolds number and the Prandtl number. The purpose of this study is to present new design correlations for flow boiling in a ternary refrigerant mixture at a meso-scale size. The relative influences of enhancement design parameters on friction factor and heat transfer were carried in this parametric analysis of the flow boiling correlations. The resulted correlations developed in this study are compared to available published correlations.

scholarly journals Development and Application of a Multi-Objective Tool for Thermal Design of Heat Exchangers Using Neural Networks

Mathematics ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1120
Author(s):  
José Luis de Andrés Honrubia ◽  
José Gaviria de la Puerta ◽  
Fernando Cortés ◽  
Urko Aguirre-Larracoechea ◽  
Aitor Goti ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Neural Networks ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Thermal Design ◽  
Design Parameters ◽  
User Friendliness ◽  
Multi Objective ◽  
Industrial Companies ◽  
Objective Tool

This paper presents the design of a multi-objective tool for sizing shell and tube heat exchangers (STHX), developed under a University/Industry collaboration. This work aims to show the feasibility of implementing artificial intelligence tools during the design of Heat Exchangers in industry. The design of STHX optimisation tools using artificial intelligence algorithms is a visited topic in the literature, nevertheless, the degree of implementation of this concept is uncommon in industrial companies. Thus, the challenge of this research consists of the development of a tool for the design of STHX using artificial intelligence algorithms that can be used by industrial companies. The approach is implemented using a simulated dataset contrasted with ARA TT, the company taking part in the project. The given dataset to develop a theoretical STHX calculator was modeled using MATLAB. This dataset was used to train seven neural networks (NNs). Three of them were mono-objective, one per objective to predict, and four were multi-objective. The last multi-objective NN was used to develop an inverse neural network (INN), which is used to find the optimal configuration of the STHXs. In this specific case, three design parameters, the pressure drop on the shell side, the pressure drop on the tube side and heat transfer rate, were jointly and successfully optimised. As a conclusion, this work proves that the developed tool is valid in both terms of effectiveness and user-friendliness for companies like ARA TT to improve their business activity.

scholarly journals Convex restrictions in physical design

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillermo Angeris ◽  
Jelena Vučković ◽  
Stephen Boyd
Keyword(s):  
Type Systems ◽  
Scalar Fields ◽  
Physical Design ◽  
Thermal Design ◽  
Design Parameters ◽  
Physical Parameters ◽  
Diffusion Type ◽  
Design Problems ◽  
Convex Optimization Problem ◽  
Practical Performance

AbstractIn a physical design problem, the designer chooses values of some physical parameters, within limits, to optimize the resulting field. We focus on the specific case in which each physical design parameter is the ratio of two field variables. This form occurs for photonic design with real scalar fields, diffusion-type systems, and others. We show that such problems can be reduced to a convex optimization problem, and therefore efficiently solved globally, given the sign of an optimal field at every point. This observation suggests a heuristic, in which the signs of the field are iteratively updated. This heuristic appears to have good practical performance on diffusion-type problems (including thermal design and resistive circuit design) and some control problems, while exhibiting moderate performance on photonic design problems. We also show in many practical cases there exist globally optimal designs whose design parameters are maximized or minimized at each point in the domain, i.e., that there is a discrete globally optimal structure.

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