Geometry optimization method based on visibility analysis: a case study

Author(s):  
Shanzheng Hu ◽  
YanXiong Chen ◽  
ShuQin Li ◽  
LongJiang Jing ◽  
ZhongLin Cao ◽  
...  
Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 377
Author(s):  
Damian Obidowski ◽  
Mateusz Stajuda ◽  
Krzysztof Sobczak

An efficient approach to the geometry optimization problem of a non-axisymmetric flow channel is discussed. The method combines geometrical transformation with a computational fluid dynamics solver, a multi-objective genetic algorithm, and a response surface. This approach, through geometrical modifications and simplifications allows transforming a non-axisymmetric problem into the axisymmetric one in some specific devices i.e., a scroll distributor or a volute. It results in a significant decrease in the problem size, as only the flow in a quasi-2D section of the channel is solved. A significantly broader design space is covered in a much shorter time than in the standard method, and the optimization of large flow problems is feasible with desktop-class computers. One computational point is obtained approximately eight times faster than in full geometry computations. The method was applied to a scroll distributor. For the case under analysis, it was possible to increase flow uniformity, eradicate separation zones, and increase the overall efficiency, which was followed by energy savings of 16% for the scroll. The results indicate that this method can be successfully applied for the optimization of similar problems.


2020 ◽  
Vol 0 (5) ◽  
pp. 45
Author(s):  
Muhammad Rayhan Azzindani ◽  
Nabila Fajri Kusuma Ningrum ◽  
Mega Rizkah Sudiar ◽  
Anak Agung Ngurah Perwira Redi

2017 ◽  
Vol 10 (2) ◽  
pp. 67
Author(s):  
Vina Ayumi ◽  
L.M. Rasdi Rere ◽  
Mohamad Ivan Fanany ◽  
Aniati Murni Arymurthy

Metaheuristic algorithm is a powerful optimization method, in which it can solve problemsby exploring the ordinarily large solution search space of these instances, that are believed tobe hard in general. However, the performances of these algorithms signicantly depend onthe setting of their parameter, while is not easy to set them accurately as well as completelyrelying on the problem's characteristic. To ne-tune the parameters automatically, manymethods have been proposed to address this challenge, including fuzzy logic, chaos, randomadjustment and others. All of these methods for many years have been developed indepen-dently for automatic setting of metaheuristic parameters, and integration of two or more ofthese methods has not yet much conducted. Thus, a method that provides advantage fromcombining chaos and random adjustment is proposed. Some popular metaheuristic algo-rithms are used to test the performance of the proposed method, i.e. simulated annealing,particle swarm optimization, dierential evolution, and harmony search. As a case study ofthis research is contrast enhancement for images of Cameraman, Lena, Boat and Rice. Ingeneral, the simulation results show that the proposed methods are better than the originalmetaheuristic, chaotic metaheuristic, and metaheuristic by random adjustment.


2015 ◽  
Vol 2015 (1) ◽  
pp. 000413-000418
Author(s):  
Wenjuan Qi ◽  
Daniel D. Evans

Modern wedge bonders have evolved since their early inception in 1957. This paper will review the common challenges process engineers face when selecting a wedge bond machine configuration and developing robust processes. Wedge bond cases presented will show the tradeoff between process inputs and the resulting bond shapes, bond appearance of black ring, burrs, pull results, etc. The purpose of this work was to optimize the process outputs: bond shape, black ring, burrs, and pulls on a die with aluminum bond pads. Process inputs included Force, Time, and Ultrasonic Level. An aluminum wafer was used to understand the basic relationship between process parameter inputs and outputs. The learning was then applied to a die with aluminum bond pads. Examples of non-compliance and compliance will be shown to help process engineers evaluate wedge bonds and make refinements. The case studied was for an aluminum bond pad/Al wafer and 1.5 mil aluminum wire interaction that creates burrs around the bond (wire to pad interface), black ring on the bond periphery (wedge tool to wire interface) and the resulting pulls. Both the graphical and numerical results of the case study have clearly demonstrated the relationship between the typical process inputs and outputs, particularly bond shape, burrs, black ring and pulls. The findings in this study will provide a general guideline and a troubleshooting reference for wedge bonding process development.


2019 ◽  
Vol 10 (4) ◽  
pp. 78
Author(s):  
Ryosuke Kataoka ◽  
Akira Shichi ◽  
Hiroyuki Yamada ◽  
Yumiko Iwafune ◽  
Kazuhiko Ogimoto

The use of batteries of electric vehicles (EVs) for home electricity applications using a bidirectional charger, a process called vehicle-to-home (V2H), is attracting the attention of EV owners as a valuable additional benefit of EVs. To motivate owners to invest in V2H, a quantitative evaluation to compare the performance of EV batteries with that of residential stationary batteries (SBs) is required. In this study, we developed a multi-objective optimization method for the household of EV owners using energy costs including investment and CO2 emissions as indices and compared the performances of V2H and SB. As a case study, a typical detached house in Japan was assumed, and we evaluated the economic and environmental aspects of solar power self-consumption using V2H or SB. The results showed that non-commuting EV owners should invest in V2H if the investment cost of a bidirectional charger is one third of the current cost as compared with inexpensive SB, in 2030. In contrast, our results showed that there were no advantages for commuting EV owners. The results of this study contribute to the rational setting of investment costs to increase the use of V2H by EV owners.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Kaijian Zhu ◽  
Weiping Huang ◽  
Yuncai Wang ◽  
Wei Niu ◽  
Gongyou Wu

Using a small near-Earth object (NEO) to impact a larger and potentially threatening NEO has been suggested as an effective method to avert a collision with Earth. This paper develops a procedure for analysis of the technique for specific NEOs. First, an optimization method is used to select a proper small body from the database. Some principles of optimality are achieved with the optimization process. Then, the orbit of the small body is changed to guarantee that it flies toward and impacts the big threatening NEO. Kinetic impact by a spacecraft is chosen as the strategy of deflecting the small body. The efficiency of this method is compared with that of a direct kinetic impact to the big NEO by a spacecraft. Finally, a case study is performed for the deflection of the Apophis NEO, and the efficiency of the method is assessed.


Author(s):  
Zhenyu Kong ◽  
Wenzhen Huang ◽  
Dariusz Ceglarek

In a number of manufacturing processes, tooling installation, calibration and maintenance guarantee the precision of fixtures and play important roles towards the overall quality of products. Recently a new type of measurement equipment called “laser tracker” was developed and utilized for assembly fixture calibration to shorten calibration time and improve the accuracy of the currently used theodolite systems. Though, the calibration of assembly fixture is critical for product quality, the calibration time creates significant burden for productivity of multi-station assembly processes. In order to shorten the calibration lead time, the number of necessary calibration setups which is determined by visibility analysis needs to be minimized. This paper presents a screen space transformation based visibility analysis that allows minimizing the number of setups. The screen space transformation is applied to transform the visibility problem from 3D to 2D space, consequently the visibility problem can be solved efficiently. A case study illustrates the procedure and verifies the validity of the proposed methodology.


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