• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.05a
• /
• pp.181-182
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.05a
• /
• pp.179-180
• /
• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.843-844
• /
• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.06a
• /
• pp.417-418
• /
• 2007

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.10a
• /
• pp.172-172
• /
• 2007

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.10a
• /
• pp.175-180
• /
• 2000

This paper describes the method and the process for impeller machining on 5-axis CNC machining center. Also, The CAD/CAM software for the impeller post processing is developed. The software can be interfaced with Solid-works software for confirmation of the impeller shapes. In this study, blades on impeller is described from Ruled-surfaces between two Ferguson curves. In this study, using 5-axis NC part program obtained from the developed software, a sample impeller was machined on 5-axis CNC machining center. The machined impeller was very agreeable to the designed impeller. Thus, theories proposed in this study can be very useful for the 5-axis machining of impeller blades with Ruled-surfaces.

• Transactions of Materials Processing
• /
• v.16 no.4 s.94
• /
• pp.288-292
• /
• 2007

This study focuses on the warm forging of a magnesium alloy impeller used for the fuel cell. The impeller has the very complicated shape with sharply twisted blade and thus is generally produced by mechanical machining or casting process. However, since these technologies give the high manufacturing cost or poor mechanical properties, the forging technology is required to make the high-quality impeller with the lower manufacturing cost. In order for production of the impeller by warm forging technology, the parametric studies using finite element analyses were carried out to find the optimal perform shape of impeller. Based on the FE simulation results, dies for impeller forging were designed and the resultant forged impeller was shown.

• 연구논문집
• /
• s.22
• /
• pp.5-19
• /
• 1992

An aerodynamic design technique of a centrifugal impeller is developed. The design procedure consists of a preliminary design, a three-dimensional blade surface generation, a flow analysis of impeller passage and a compatibility analysis for the designed impeller. To get a higher efficiency, the backswept impeller which has a lean angle and a parabolic blade surface is designed. In the present analysis of flow in an impeller, an inviscid quasi-three-dimensional method and a viscous three-dimensional method are used. Compatibility of the designed impeller is decided with the results of the analyses. The quasi-three-dimensional method is easy to use, but limited to a few conditions in real application for the prediction of the actual flow in the impeller. Since the viscous three-dimensional method proved to predict the real flow in the impeller relatively well, it can be used as a means for the decision of compatibility of the designed impeller.

• Journal of Power System Engineering
• /
• v.12 no.5
• /
• pp.20-26
• /
• 2008

양산되는 승용차용 토크 컨버터 내부의 유동을 LDV 측정 기술을 이용하여 정량화했다. 속도비 0.4와 0.8 경우에 대한 속도 측정을 통해 임펠러 유로 중간과 출구 영역의 질량 유동율 특성을 분석했다. 측정 단면의 속도 분포는 유로의 위치와 속도비에 따라 많은 차이를 보이며, 특히 속도비 0.8 조건에서 임펠러 유로 중간영역 흡입면 부근의 유동은 유동박리에 의한 재순환 현상을 나타내며, 이와는 대조적으로 출구 영역에서는 흡입면을 따라 역류 현상이 발생한다. 임펠러 유로 내부의 유동은 각 영역에서 속도비에 따라 개별적 유동 특성을 보인다. 질량 유동율은 모든 속도비와 측정단면에서 주기적인 변화를 보이며, 또한 터빈의 순간적인 위치가 임펠러 유로 측정단면의 질랑 유동율에 매우 큰 영향을 미치는 것이 밝혀졌다 따라서 토크 컨버터 임펠러의 유로 방향 유동 특성 변화는 컨버터 설계에 중요하게 고려되어야 할 것으로 보인다.

• The KSFM Journal of Fluid Machinery
• /
• v.16 no.1
• /
• pp.11-16
• /
• 2013

A numerical study was conducted to improve the performance of an impeller of centrifugal compressor. Nine design variables were chosen with constraints. Only meridional contours and blade profile were adjusted. ANN (Artificial Neural Net) was adopted as a main optimization algorithm with PSO (Particle Swarm Optimization) in order to reduce the optimization time. At first, ANN was learned and trained with the design variable sets which were obtained using DOE (Design of Experiment). This ANN was continuously improved its accuracy for each generation of which population was one hundred. New design variable set in each generation was selected using a non-gradient based method of PSO in order to obtain the global optimized result. After $7^{th}$ generation, the prediction difference of efficiency and pressure ratio between ANN and CFD was less than 0.6%. From more than 1,200 design variable sets, a pareto of efficiency versus pressure ratio was obtained and an optimized result was selected based on the multi-objective function. On this optimized impeller, the efficiency and pressure ratio were improved by 1% and 9.3%, respectively.