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During the last 20 years trade between Korea and Mexico has increased steadily, reaching $2.8 billion in 2003. This trade expansion will be further accelerated with the increase…
Abstract
During the last 20 years trade between Korea and Mexico has increased steadily, reaching $2.8 billion in 2003. This trade expansion will be further accelerated with the increase in intra-industry trade in the future. Mexico's chronic trade deficit against Korea, which is attributed to Korea's increasing investment in Mexico, has rather contributed to Mexico's exports to the American region.
As Mexico expands its FTA networks, Korean companies are having difficulties in accessing the Mexican market. Considering this situation and the economic benefits of a Korea-Mexico FTA for both countries, we should first expand cooperation between private sectors, which is expected to facilitate a formal discussion on the Korea-Mexico FTA.
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Babak Lotfi and Bengt Ake Sunden
This study aims to computational numerical simulations to clarify and explore the influences of periodic cellular lattice (PCL) morphological parameters – such as lattice…
Abstract
Purpose
This study aims to computational numerical simulations to clarify and explore the influences of periodic cellular lattice (PCL) morphological parameters – such as lattice structure topology (simple cubic, body-centered cubic, z-reinforced body-centered cubic [BCCZ], face-centered cubic and z-reinforced face-centered cubic [FCCZ] lattice structures) and porosity value ( ) – on the thermal-hydraulic characteristics of the novel trussed fin-and-elliptical tube heat exchanger (FETHX), which has led to a deeper understanding of the superior heat transfer enhancement ability of the PCL structure.
Design/methodology/approach
A three-dimensional computational fluid dynamics (CFD) model is proposed in this paper to provide better understanding of the fluid flow and heat transfer behavior of the PCL structures in the trussed FETHXs associated with different structure topologies and high-porosities. The flow governing equations of the trussed FETHX are solved by the CFD software ANSYS CFX® and use the Menter SST turbulence model to accurately predict flow characteristics in the fluid flow region.
Findings
The thermal-hydraulic performance benchmarks analysis – such as field synergy performance and performance evaluation criteria – conducted during this research successfully identified demonstrates that if the high porosity of all PCL structures decrease to 92%, the best thermal-hydraulic performance is provided. Overall, according to the obtained outcomes, the trussed FETHX with the advantages of using BCCZ lattice structure at 92% porosity presents good thermal-hydraulic performance enhancement among all the investigated PCL structures.
Originality/value
To the best of the authors’ knowledge, this paper is one of the first in the literature that provides thorough thermal-hydraulic characteristics of a novel trussed FETHX with high-porosity PCL structures.
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Marcelo Colaço, Fabio Bozzoli, Luca Cattani and Luca Pagliarini
The purpose of this paper is to apply the conjugate gradient (CG) method, together with the adjoint operator (AO) to the pulsating heat pipe problem, including some quite…
Abstract
Purpose
The purpose of this paper is to apply the conjugate gradient (CG) method, together with the adjoint operator (AO) to the pulsating heat pipe problem, including some quite interesting experimental results. The CG method, together with the AO, was able to estimate the unknown functions more efficiently than the other techniques presented in this paper. The estimation of local heat transfer coefficients, rather than the global ones, in pulsating heat pipes is a relatively new subject and presenting a robust, efficient and self-regularized inverse tool to estimate it, supported also by some experimental results, is the main purpose of this paper. To also increase the visibility and the general use of the paper to the heat transfer community, the authors include, as supplemental material, all numerical and experimental data used in this paper.
Design/methodology/approach
The approach was established on the solution of the inverse heat conduction problem in the wall by using as starting data the temperature measurements on the outer surface. The procedure is based on the CG method with AO. The here proposed approach was first verified adopting synthetic data and then it was validated with real cases regarding pulsating heat pipes.
Findings
An original fast methodology to estimate local convective heat flux is proposed. The procedure has been validated both numerically and experimentally. The procedure has been compared to other classical methods presenting some peculiar benefits.
Practical implications
The approach is suitable for pulsating heat pipes performance evaluation because these devices present a local heat flux distribution characterized by an important variation both in time and in space as a result of the complex flow patterns that are generated in this type of devices.
Originality/value
The procedure here proposed shows these benefits: it affords a general model of the heat conduction problem that is effortlessly customized for the particular case, it can be applied also to large datasets and it presents reduced computational expense.
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Yong Li, Yingchun Zhang, Gongnan Xie and Bengt Ake Sunden
This paper aims to comprehensively clarify the research status of thermal transport of supercritical aviation kerosene, with particular interests in the effect of cracking on heat…
Abstract
Purpose
This paper aims to comprehensively clarify the research status of thermal transport of supercritical aviation kerosene, with particular interests in the effect of cracking on heat transfer.
Design/methodology/approach
A brief review of current research on supercritical aviation kerosene is presented in views of the surrogate model of hydrocarbon fuels, chemical cracking mechanism of hydrocarbon fuels, thermo-physical properties of hydrocarbon fuels, turbulence models, flow characteristics and thermal performances, which indicates that more efforts need to be directed into these topics. Therefore, supercritical thermal transport of n-decane is then computationally investigated in the condition of thermal pyrolysis, while the ASPEN HYSYS gives the properties of n-decane and pyrolysis products. In addition, the one-step chemical cracking mechanism and SST k-ω turbulence model are applied with relatively high precision.
Findings
The existing surrogate models of aviation kerosene are limited to a specific scope of application and their thermo-physical properties deviate from the experimental data. The turbulence models used to implement numerical simulation should be studied to further improve the prediction accuracy. The thermal-induced acceleration is driven by the drastic density change, which is caused by the production of small molecules. The wall temperature of the combustion chamber can be effectively reduced by this behavior, i.e. the phenomenon of heat transfer deterioration can be attenuated or suppressed by thermal pyrolysis.
Originality/value
The issues in numerical studies of supercritical aviation kerosene are clearly revealed, and the conjugation mechanism between thermal pyrolysis and convective heat transfer is initially presented.
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Supertall towers (300 m+) offer a viable solution to the increasing demand for housing and commercial space caused by rapid urban growth, migration from rural to urban areas and…
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Purpose
Supertall towers (300 m+) offer a viable solution to the increasing demand for housing and commercial space caused by rapid urban growth, migration from rural to urban areas and economic expansion in Asia. In this particular context, the efficient utilization of space becomes a crucial factor in the design process for Asian skyscrapers as they seek to address the changing socioeconomic landscape. This study will provide valuable guidance, especially to architectural and structural designers in the pursuit of sustainable development for Asian skyscrapers by analyzing space efficiency.
Design/methodology/approach
The methodology employed in this paper involved a case study approach to gather data on 75 Asian supertall towers in order to examine space efficiency.
Findings
Findings of the research can be summarized as follows: (1) the average space efficiency of these towers was 67.5%, ranging from a minimum of 55% to a maximum of 82%; (2) the average proportion of the core area to the gross floor area (GFA) was 29.5%, with values ranging from 14% to 38%; (3) the majority of Asian skyscrapers exhibited a tapered form and adopted a central core typology, which catered to mixed-use and office purposes; (4) the most frequently utilized structural system was a combination of composite and outriggered frames; (5) space efficiency tended to decrease as the height of the tower increased; and (6) there was no noteworthy difference in the impact of various load-bearing systems and building forms on space efficiency.
Originality/value
There is a noticeable lack of extensive research into space efficiency in supertall towers in Asia, which serves as a hub for skyscrapers. This study seeks to fill this substantial gap in the current scientific literature.
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