• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.568-571
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• 2004

This paper presents an efficient 5-axis roughing method for centrifugal impeller. The efficient roughing is minimization of cutting time through minimizing tool tilting & rotating motions. Roughing tool path plan consists of the three steps. First, machining areas are divided into sub cutting regions using ruling lines. The biggest tool diameter is, then, determined for each region. Finally, tool paths are generated after fixing the tilting and rotating axis of 5-axis machine. Experimental results showed that the proposed roughing plan considering the divided machining regions is more efficient than the conventional methods.

• 한국전산유체공학회지
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• 제3권1호
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• pp.30-36
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• 1998

The three dimensional Navier-Stokes equations in rotational coordinate are solved using a multigrid algorithm for the calculations of turbulent flows in centrifugal compressor impellers. Some numerical studies are made in applying the multigrid algorithm for the turbulent flow calculations with the standard κ-ε equations. The present method is used to calculate the flow fields of Mizuki's B-type and Niigata Ms. 350 centrifugal compressor impellers. Fast convergent steady-state solutions are carefully examined, comparing the static pressure distributions along the impeller flow passage and also in the diffuser with experimental data. Performance of a centrifugal compressor system is also numerically validated by comparing the performances of the impeller and the diffuser individually.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.102-107
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• 2007

The steel impeller placed in a water pump has been studied with the aim to understand corrosion phenomena on the surface responsible for reducing the pumping efficiency of water inside cooling system. This preliminary experiment includes a period (around 1 month) observation with a powered microscope and weight measurements. The experiments are carried out at different conditions of water and mixtures of water and coolants, based on the water contents of 25%, 50%, 75%, and 100% water (pure tap water). From the visual results of microscopy, most of the steel surface is fitted and clear rusty or corrosion phenomena are noticeable as time goes. In addition, the weight loss of the sample specimen submerged in the water is linearly increased, whereas those in the mixtures of water initially gain weight and become almost constant.

• 동력기계공학회지
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• 제13권1호
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• pp.46-52
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• 2009

The steel impeller placed in a water pump has been studied with the aim to understand corrosion phenomena on the surface responsible for reducing the pumping efficiency of water inside cooling system. This preliminary experiment includes a period (over 5 months) observation with a powered microscope and weight measurements. The experiments are carried out at different conditions of water and mixtures of water and coolants, based on the water contents of 25%, 50%, 75%, and 100% water (pure tap water). From the visual results of microscopy, most of the steel surface is fitted and clear rusty or corrosion phenomena are noticeable as time goes. In addition, the weight loss of the sample specimen submerged in the water is linearly increased, whereas those in the mixtures of water initially be constant and then gain weight linearly.

• 한국산업융합학회 논문집
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• 제10권4호
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• pp.263-269
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• 2007

A numerical algorithm for three-dimension laminar flow in an agitated vessel was established by using the spherical coordinates. Flow pattern for the double-stage paddle impeller was not dependent upon the distance of among the impeller in the agitated vessels. The numerical simulation of the flow pattern in spherical and cylindrical agitated vessel agree well with the visualization results.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.399-404
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• 2002

An efficient method of machining impeller is presented. In the roughing process, the cutting area is divided into two regions to reduce cutting time and select cutting tools. The regions are determined by characteristic point on the geometry of impeller blade. Then, the tool of the maximum radius is selected in each area. Tool interference in cutting areas is avoided by checking the intersection between cooing tool axis and ruling line on blade surface.

• 한국기계가공학회지
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• 제13권1호
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• pp.1-7
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• 2014

An impeller is difficult to machine due to the complex, overlapping and twisted shapes that form the blades of an impeller. Therefore, most CAM software companies have developed a CAM module for manufacturing an impeller in addition to their CAM software. However, it is not easy for inexperienced users to machine impellers. The purpose of this paper is to outline the development of an automatic CAM module for the manufacturing of an impeller (E-ICAM) which is based on visual basic language and which uses a CATIA graphical environment in order to simplify the machining of impellers. The automatic CAM module generates a tool path and proposes the recommended cutting condition according to the stock and tool material. In addition, it includes a post-processor for five-axis control machining. Therefore, a user can easily machine impellers using this automation module. There are two types of impellers: the closed and open types. The closed-type impeller consists of the body and cover parts. To combine these two parts, it is necessary to create tap holes on the shroud of the body. Therefore, in the study, a drilling CAM program for a closed-type impeller is developed and manufactured by creating NC data from the developed drilling program. After manufacturing the test specimen, its compatibility was verified.

• 한국산학기술학회논문지
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• 제10권12호
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• pp.3533-3539
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• 2009

에어컨 임펠러는 에어컨에 장착되어지는 부품으로서 모터 구동에 의하여 차가운 바람을 실내로 유입되도록 해주는 부분이다. 본 연구에서는 임펠러의 파손 원인을 수치적인 방법에 의하여 규명하고, 공진에 의한 파손 여부를 평가한다. 임펠러의 공진 여부를 판단하기 위하여 임펠러의 고유진동수와 Aerodynamic force에 의한 특성 주파수를 비교한다. 먼저, 임펠러의 고유진동수를 알기 위하여 모드 실험과 수치 계산을 병행한다. 즉, 구조 해석용 상용 소프트웨어인 ANSYS를 이용하여 고유진동수와 모드 형을 계산하고, 이를 확인하기 위하여 실험적 주파수 분석을 수행한다. 공진 현상의 원인이 되는 외력에 대하여 임펠러 Blade에 작용하는 Aerodynamic force를 구하여야 하며, 본 연구에서는 V.E.M.(Vortex Element Method)에 근거한 유동 해석 프로그램을 수행하여 Aerodynamic force에 의한 특성 주파수를 얻는다.

• Journal of Advanced Marine Engineering and Technology
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• 제39권3호
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• pp.248-254
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• 2015

국내에는 아직 침수선박 구조용 대용량 배수펌프에 대한 기술개발 사례가 없는 상황이다. 현재 침수선박 구조를 위해 농업용 배수펌프가 사용되고 있으나 실효성이 현저히 떨어지며, 낮은 배수량, 이물질 걸림 현상, 겨울철 운전 오작동 등의 문제점이 있다. 따라서 본 논문에서는 해양에서 신속한 침수선박의 구조를 위해 현재 장비가 가지는 문제점을 개선하여 분당 20 톤의 배수량을 가지는 대용량 배수펌프 시스템을 개발하고자 한다. 대용량 배수펌프 시스템은 펌프 배출구를 통해 배출되는 흡입양정 8 m에서 분당 20 톤의 해수를 배출하는 것을 목표로 배수펌프 시스템 설계 및 개발을 수행하였다. 펌프종류는 조선해양 분야에서 액체를 이송하는데 가장 많이 사용되는 원심펌프를 채택하였으며, 요구 시방을 기초로 펌프를 설계하였다. 임펠러 블레이드는 요구 시방과 Stepanoff 설계 상수를 이용하여 임펠러 제원과 블레이드 입출구각을 도출하였고, 설계된 임펠러와 하우징 형상에서 목표 유량 만족 여부를 확인하기 위해 유동해석을 수행하여, 임펠러 회전수에 따른 유량을 검토하였다. 또한 실제 운전 중에 발생할 수 있는 제품에 대한 구조적인 취약성을 판단하기 위해 임펠러 구조해석을 수행하여 안전성을 검토하여, 침수선박 구조를 위한 배수펌프 시스템 개발을 완료하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.366-366
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• 2009