• 한국유체기계학회 논문집
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• 제16권6호
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• pp.12-18
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• 2013

This paper presents the performance characteristics of a centrifugal blower using the design parameters of an impeller blade. Two design variables, the bending length from the blade trailing edge and bending angles of an impeller blade, are introduced to analyze the effects on the blower performance. Three-dimensional Navier-Stokes equations with shear stress transport turbulence model are introduced to analyze the performance and internal flow of the blower. Relatively good agreement between experimental measurements and numerical simulation at the design flow condition is obtained. Throughout present study, it is known that pressure increases as the bending length from the trailing edge and bending angle increase while efficiency decreases. But efficiency is decreased. Detailed flow field inside the centrifugal blower is also analyzed and compared.

• 드라이브 ㆍ 컨트롤
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• 제18권4호
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• pp.35-42
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• 2021

A personal mobility withstanding function for the disabled and vulnerable groups with difficulties in mobility was developed and structural and dynamics analysis was conducted. Personal mobility devices are a very helpful means of transportation for the disabled and vulnerable groups. In addition, the standing function allows individuals to perform a difficult task in while seated and offers a medical advantage to the user. In this study, a personal mobility device was designed and developed to help vulnerable groups and disabled people overcome limited mobility, and communicate with the general people at eye level through standing functions. Through structural and dynamic analysis, the structural safety, optimal speed during rotation, and lateral acceleration of the personal mobility device was analyzed. The analysis results are expected to contribute to the improvement of the users' convenience and stability of personal mobility.

• 한국가스학회지
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• 제25권4호
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• pp.36-42
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• 2021

쓰레기 매립지에 발생하는 매립지가스(Landfill gas)를 대기 중으로 방출할 경우에 매립지가스에서 많은 부분을 차지하고 있는 지구온난화 지수(global warming potential)가 높은 메탄가스를 배출하게 되어 기후변화에 악영향을 주게 되고, 매립지가스에 함유되어 있는 메탄을 내연기관의 연료로 활용하여 연소하여 발전을 하게 되면 이산화탄소 형태로 대기 중으로 배출하게 되어 온난화 지수를 낮추는 데도 기여를 할 수 있게 된다. 따라서 매립지가스를 내연기관을 이용한 발전용 연료로 사용하기 위해서 엔진의 열효율을 높이는 것이 중요하기 때문에 기존의 믹서 방식 기술을 이용한 연료공급 방식보다는 실린더별로 흡기포트에서 전자 제어 인젝터를 이용하여 기체 분사를 하는 방식의 연료공급 시스템을 사용하는 것이 필요하게 된다. 따라서 전자 제어 기체 분사 방식 기술을 이용하기 위해서는 매립지가스의 사용 조건에 따른 질량 유량을 정확히 측정하는 것이 중요하게 된다. 이를 위하여 본 연구에서는 매립지가스를 기체 분사할 경우에 분사량을 측정 및 계산하는 연구를 수행하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.421-422
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• 2011

• 한국기계가공학회지
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• 제20권12호
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• pp.44-53
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• 2021

As environmental issues have emerged worldwide, emission gas regulations have been strengthened. In the construction machinery sector, studies have been actively conducted to utilize the power source of electric motors owing to the increasing demand for zero emissions. In this study, the gear specifications of an electric axle for construction machinery were selected by considering the specifications of the motor, gear tooth contact pattern, and face load factor. The gear strength evaluation was performed at the system level using the simulation model. The bending and contact strength of the spiral bevel gears and the bending strength of the planetary gear set showed a safety factor of 1 or more. However, the contact strength of the planetary gear set showed a safety factor of 0.92. Conservative results were derived by performing the analysis under the rated load condition of the motor. However, the ratio of the equivalent torque to the rated torque of the motor was 45% or less, hence, it was determined that no difficulties should arise regarding the durability of the axle.

• 드라이브 ㆍ 컨트롤
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• 제4권4호
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• pp.78-83
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• 2007

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.171-172
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• 2020

Recently, the need for smart construction technologies related to the Fourth Industrial Revolution has been increasing in order to improve productivity of the construction industry. The Ministry of Land, Infrastructure and Transport has established Smart construction technology road map to commercialize the smart construction, and research and development is also underway. However, due to the lack of cost estimation standards for such smart construction technologies to be deployed to actual sites, smart construction technologies are not actively applied to construction sites. In particular, cost estimation standards are needed for construction machinery equipment with ICT technology that is currently available for commercialization. Therefore, as a preliminary study for the development of smart construction cost estimation standards, a case study was conducted on ICT construction estimation standards in Japan and present them as basic data for standards in Korea.

• 드라이브 ㆍ 컨트롤
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• 제21권2호
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• pp.73-76
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• 2024

• 한국신뢰성학회지:신뢰성응용연구
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• 제11권3호
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• pp.235-244
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• 2011

Hydraulic hose assemblies deliver a fluid power in various oil pressure equipment such as construction machinery, automobile, aircraft, industrial machinery, machine tools and machinery for ships. Also, they are widely used as pipes in oil pressure circuit. When we estimate their lifetime, it is essential to conduct an accelerated life test by choosing the factor that suits the usage condition of the test object since traditional test method for estimating lifetime under the influence of various external factors incurs hardship in terms of time and expenses. The objective of this study is to propose an acceleration model that takes both temperature and pressure without flexing condition into consideration. The lifetime is estimated by applying the proposed temperature-nonthermal acceleration model to the test data. And we compare the proposed temperature-nonthermal acceleration model and the accelerated life equation suggested by John(1994).

• 한국안전학회지
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• 제25권6호
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• pp.146-154
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• 2010

In this study the experimental results of fatigue specimen for the Strand Stay Cable Assembly of Extadosed bridges is investigated. The fatigue test and tensile experiment is conducted to 6 kinds of specimens. Test specimen OVM250-31 Strand Cable System manufactured by china OVM B-Machinery Co., Ltd, and OVM250-42 Parallel Strand Stay Cable Assembly manufactured by china OVM B-Machinery Co., Ltd, are passed for fatigue test and rupture tensile test. But Test specimen OVM250-42 Parallel Strand Stay Cable Assembly manufactured by korean A-Machinery Co., Ltd, is not passed for fatigue test conducted according to the "Recommendation for Stay Cable Design. The test result are compared to the fatigue criteria of PHI 2001 for cyclic load, and it is concluded that the current korean design code will be needed for representing the fatigue load in Hot Dip Galvanized Strand Stay Cable. It is verified that the new korean specification and quality criteria of Strand Stay Cable and exact experimental applied process will be needed.