• Journal of Advanced Marine Engineering and Technology
• /
• v.41 no.4
• /
• pp.323-329
• /
• 2017

Nowadays, considering global warming and enhanced prohibition to discharge pollutants at sea, all of existing operation-ships must lead to the reduction of fuel consumption. International standards of International Maritime Organization and EU rules governing harbor pollutants are being strengthened. Therefore, ship-owners and operators are seeking ways to reduce $CO_2$, SOx, and NOx emissions. Although world trade continues to expand, total fuel usage for sea transport tends to diminish. However, ICS(International Chamber of Shipping) has set a goal of reducing $CO_2$ emissions from shipping by 50% until 2050. In addition, with respect to the Paris Climate Change Accord in 2015, IMO proposes to set up a reduction target of GHG emission from existing operation-ships. For setting up a reduction target of GHG from international maritime transport, "A data collection system for fuel consumption" will be introduced in the near future. In order to effectively reduce the use of fuel in a ship in accordance with the trend of compulsory fuel saving from operation ships, this paper suggested adoption of an Incentive-Penalty scheme based on Emission-Trading-Scheme, Carbon Tax, and basic calculation formula after verifying the EEOI level for a year.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.10
• /
• pp.1-7
• /
• 2017

This study investigates the high-frequency heat treatment characteristics with the distance between a coil and SCM440 parts for an automobile. Global automobile makers are focusing on research to develop high-performance automobiles with improved fuel efficiency and lower emissions in accordance with consumer demand and environmental policies. However, most research on high-frequency heat treatment has been experimental, and it is very difficult to obtain high-frequency heat treatment conditions for a specific product. Therefore, all the conditions of high-frequency heat treatment except the distance between a coil and SCM440 parts were kept the same. As a result, the optimized distance between the coil and SCM440 parts was observed to be 1-2 mm. When the distance between the coil and SCM440 parts was over 3 mm, the effective case hardness depth and total case hardness depth did not satisfy the standards.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.10
• /
• pp.725-732
• /
• 2017

Weight reduction is one of the important issues in the automotive industry and the development of internal combustion engines vehicles, future vehicles, and eco-friendly vehicles for improving fuel efficiency. The objective of this study is to investigate the improvement of driving performance by weight reduction and optimum design for a formula-type self-designed on-road vehicle. This study is divided into the four steps. Firstly, the engine room was replaced and designed with a lighter engine. Secondly, an optimization study was conducted to simplify and lighten the vehicle components with the design of the frame. Thirdly, the structure design was optimized and the suspension was analyzed with the design of the frame. Finally, the design of an upright and hub with reduced weight was carried out using lighter parts. As a result, we reduced the weight of the vehicle by 48.5kg compared to the previous year (19.5%) and increased the acceleration from 6.8 s to 5.8 s.s.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.8
• /
• pp.200-207
• /
• 2016

The automotive seat is an important component that moves in sync with the driver and is actively being developed with various new functions. The aim of this work is to develop a lightweight seat cushion extension module using a lightweight material. To this end, a structural strength analysis, vertical strength test, and durability test were conducted. In the structural analysis, the maximum value of deformation under vertical load was 4.98 mm at the front of the upper panel. The maximum stress was approximately 105 MPa, which occurred at the point of contact between the upper and lower panels of the module. The vertical strength test showed a maximum vertical deformation of 5.31 mm under a vertical load, which differed from the analysis results by approximately 6.45%. The structural safety of the product was verified by the fact that it showed no harmful deformation or damage during operation after the vertical strength test and a durability test for 20,000 cycles. Furthermore, the use of engineering plastics made it possible to reduce the weight by approximately 30% compared to existing products. The lack of damage after tests verified the passenger safety, strength, and rigidity of the product. The results are expected to be applied for improving environmental and fuel efficiency regulations and preventing accidents due to driver fatigue. The applications of this module could be expanded various types of vehicles, as well as other industries in which eco-friendly and lightweight materials are used.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.723-729
• /
• 2019

Turbochargers are an effective device to reduce the fuel consumption. In this study, the mass flow rate of pulsating flow in the twin-scroll turbocharger for the gasoline engine of passenger vehicles was measured. Pulsating flow was achieved using a pulse generator and the mass flow rate of the unsteady pulsating flow was analyzed by comparing it with those of the steady flow. The pulse generator consisted of a rotating upper plate and a fixed lower plate. To measure the mass flow rate of unsteady flow, the orifice flow meter equipped with the difference pressure transducer was used. To analyze the low speed performance of the turbocharger, the measurement was carried out in the speed of turbocharger from 60,000rpm to 100,000rpm. The mass flow parameters of the unsteady pulsating flow showed a large difference compared to those of the steady flow. Those of the unsteady flow showed the hysteresis loop surrounding the mass flow parameters of the steady flow and the maximum variation of the mass flow parameters were 5.0 times those of the steady flow. This phenomenon is the result of the filling and emptying the turbine volute space due to pulsating flow.

• Proceedings of the KWS Conference
• /
• 2009.11a
• /
• pp.19-19
• /
• 2009

최근, 유한한 에너지 자원의 한계와 지구 온난화 등으로 세계의 제조 산업은 새로운 국면을 맞이하고 있으며, 특히, 자동차 산업은 화석연료를 주 에너지원으로 사용한다는 점과 이 연료를 연소시킬 때 발생하는 이산화탄소가 지구 온난화의 주된 원인이 될 수 있다는 점에서 상기 문제들을 해결하기 위한 다양한 방법에 주목하고 있다. 그 중에서 자동차의 생산기술 측면에서 볼 때, 가장 중요한 이슈는 차체 경량화다. 자동차 차체는 자동차를 구성하고 있는 여러 가지 부품 중에서 약 40% 정도의 무게 비율을 차지하고 있기 때문에, 차체 경량화는 연비향상과 이산화탄소 배출가스 감소와 직접적인 관계를 가지고 있다. 다양한 차체 경량화 방법 중에서 가장 쉽게 접근할 수 있는 방법이 경량소재 적용에 의한 경량화 방법이다. 현재, 탄소섬유 강화 플라스틱과 같이 무게 절감 비율을 최대화 할 수 있는 소재들도 개발되어 일부 적용되고 있지만, 일반적으로 차체 경량화 소재로 가장 널리 사용되고 있는 소재는 알루미늄 합금이며, 이에 대한 차체 적용 비율이 점차로 높아지는 추세에 있다. 이에, 본 연구에서는 알루미늄 합금이 차체에 적용되었을 때의 장단점을 살펴보고, 알루미늄 합금을 적용한 차체 생산과정에서 유의해야 될 사항들과 이를 바탕으로 하는 생산성 극대화 방안에 대하여 고찰하였다. 먼저, 기존의 알루미늄 저항 점 용접공법의 단점을 최소화하고 대량생산 체계에 적합하도록 개발된 새로운 개념의 저항 점 용접 시스템에 대해 그 성능과 양산성을 검증하였다. 구리 전극과 알루미늄 피용접물 사이에 프로세스 테이프를 삽입하여 용접하는 이 시스템은 열전도성이 큰 알루미늄 용접부에서 저전류의 조건에서도 효과적으로 균일한 발열현상이 발생하게 하였으며, 전극 팁 드레싱 없이 모든 용접점이 항상 동일한 조건에서 용접이 이루어질 수 있도록 하였다. 용접 조건 설정에 있어서도 용접전류가 통전되는 순간에 전극 가압력을 자유로이 변형시켜 용접부 크랙 발생을 최소화할 수 있음을 확인하였다. 알루미늄의 또 다른 대표적인 접합방법인 아크용접에 있어서는 용접 입열량을 조절하여 용접변형을 최소화 할 수 있는 아크용접 시스템에 대해 양산성과 적용 타당성을 검토하였다. 와이어 송급 방향을 자유자재로 바꿀 수 있는 이 시스템의 특성에 의해 스패터를 최소화하면서 용융금속이 효과적으로 모재에 금속이행 될 수 있음을 확인하였으며, 판재, 압출재, 및 다이캐스팅재 등 다양한 차체 소재에 대한 용접 가능성 및 미그-레이저 하이브리드 용접과의 비교분석을 통하여 차체 박판 용접에서도 최소의 열변형으로 효과적으로 사용될 수 있음을 보였다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.7
• /
• pp.629-634
• /
• 2017

In the case of the UHP (Ultra high performance) tire that the demand has increased rapidly, compared with the commonly used tire, severe deformation has been observed because of the low aspect ratio. When repeated deformations are applied to the sidewall rubber, accumulated fatigue damage may cause fatigue failure. Thus, the evaluation of the durability of the tire sidewall rubber has become a very important issue to prevent accidents that occur while the vehicle is running. However, the research and design criteria for the durability performance of the tire sidewall rubber hardly exist. In this study, we suggest a lifetime prediction formula using strain energy density obtained by performing tensile tests and fatigue tests on two different kinds of the tire sidewall compounds. Additionally, the applicability of our findings for low fuel consumption tires was reviewed by converting the fatigue life of the sidewall rubber into the expected mileage of the tire.

• Journal of Energy Engineering
• /
• v.24 no.4
• /
• pp.42-47
• /
• 2015

While the oxygen content of gasoline for automobiles in Korea is regulated to less than 2.3 weight %, European and World-Wide Fuel Charter (WWFC) regulate it to less than 2.7 weight %. The oxygen content of oxygen-containing materials increases the octane number of the fuel due to the secondary combustion in the internal combustion engine. It has been reported to be effective in reducing emissions, such as CO, HC, which is caused by incomplete combustion. Before 2000s in the United States and Europe, there has been many researches about vehicle application of the changes in oxygen content of gasoline. However, there are not many domestic researches which reflect the improvement of the fuel quality and automotive technology. In this study, fuels of three different oxygen contents were applied to GDI and MPI engines. As a result, the changes of fuel consumption and emission gas were very similar depends of the oxygen content changes. The PN in GDI engine was decreased as the oxygen content was increased.

• Journal of the Korean Magnetics Society
• /
• v.25 no.6
• /
• pp.189-197
• /
• 2015

As enforced the regulation of fuel efficiency, the electrification of automotive components in internal combustion vehicle has been applied instead of hydraulic pressure. A typical example of such parts is the EPS (electric power steering), and it is applied to most automotive at present. In electric power steering system, the core component is motor. The reduction of cogging torque and torque ripple is required to improve steering feeling and reduce NVH (Noise Vibration Harshness) in EPS. Generally the skewed design of stator or rotor is applied in order to reduce cogging torque and torque ripple. This paper propose the design and analysis methodology of Brusheless PMSM (Permanent Magnet Synchronous Motor) which is applied to skewed stator. The proposed methodology is as follows: First Intial Design PMSM with skewed stator for EPS, Second Optimal design using RSM (Response surface method), Third Performance Analysis such as Phase Back EMF, Inductance, Load torque using FEA (Finite Element Method). Finally, the reliability of proposed design methodology will be verified through the experiments of prototype sample.

• Journal of the Korean Magnetics Society
• /
• v.22 no.3
• /
• pp.109-115
• /
• 2012

NeFeB anisotropy bonded magnet has proposed a new paradigm of weight reduction of small motors by replacing the conventional ferrite permanent magnets with its high magnetic property of 25 MGOe during last five years. It has also advanced by leaps and bounds in the field of motor industry for automobiles and electric power tools. And it has led a new innovation of fifty percent weight lightening compared to its current motors by correctly focusing on fuel performance improvement through weight lightening that automobile industry chased. There was, however, another price skyrocketing in 2011 after China had announced its export regulation in rare earth materials in July, 2010. And this price change has an extensive impact on the industries that consume rare earth magnets. This environmental change has caused technical challenge to improve the performance by using least amount of rare earth elements in NdFeB anisotropy bonded magnets, and led to make a new technical approach to a new applied field. In this article, we will show how each nation deals with this industrial issue, and introduce development trend and application of anisotropic NdFeB bonded magnets, so-called MAGFINE made by Aichi Steel Corp.