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A Study on the Enhancement of Industrial Boiler by Air Flow Control
오용희(Yong Hee Oh),모용선(Yong Seon Mo),정윤교(Yoon Gyo Jung),조영태(Young Tae Cho) Korean Society for Precision Engineering 2017 한국정밀공학회지 Vol.34 No.10
Industrial boilers are used in numerous fields, and heat efficiency enhancement is a major topic of study. A double-pipe boiler is a simply structured industrial boiler having a high thermal efficiency. Baffles are specially installed in the doublepipe boiler for increasing the heating time. The baffles determine the heat efficiency of the double-pipe boiler. However, it is theoretically difficult to design a baffle and locate its optimal position, solely by considering the fluid flow of heated air, and the heat exchange between water and heated air. To confirm the correct positioning of baffles, fluid flow and heat transfer simulations were conducted on the boiler. Our results showed that at some points, there was insufficient circulation of heated air. To overcome this problem, baffles were added at these points, by referring to the simulation results. The changing of baffles resulted in an increase in efficiency of heat transfer in the double-pipe boiler.
소형발사체 추진제 탱크 부품 제조를 위한 Al2198 판재의 스프링백 영향과 냉간 압연 성형 공정 시뮬레이션
이제민(Je-Min Lee),모용선(Yong-Seon Mo),박건태(Geon-Tae Park),김석(Seok Kim),조영태(Young-Tae Cho) 한국기계가공학회 2024 한국기계가공학회지 Vol.23 No.4
This study conducts a roll forming process analysis of the Al2198 plate used in the fabrication of skirt and cylinder of a small launch vehicle propellant tank. It focuses on key parameters in the rolling machine and roll forming process, namely, the lowering length of the upper roll and the distance between the lower rolls. To account for the springback effect, the Euler Angle of the plate was measured through bending analysis, and the distance between the lower rolls was carefully selected. Based on these considerations, a model for the roll forming process was designed. The findings reveal that reducing the gap between the lower rolls minimizes the springback effect, and the radius of curvature, influenced by the deformation of the plate, varies with the lowering length of the upper roll. Utilizing a numerical analysis approach that considers sheet material characteristics and process environment variables, the study infers the radius of curvature for the displacement of the upper roll. This approach offers an alternative method to streamline the roll forming process, reducing the need for extensive trial and error.
항공기 Bulkhead의 Chord와 Side Fitting 부품의 밀링 가공 및 변형에 관한 연구
김도혁(Do Hyeog Kim),정윤교(Yoon Gyo Jung),모용선(Yong-Seon Mo),조영태(Young Tae Cho) 한국생산제조학회 2020 한국생산제조학회지 Vol.29 No.1
Among bulkhead components (the structure that maintains the rigidity of an aircraft body), the chord (which supports the shear load between the surrounding structure and the web) and the side fitting (which connects and vertically reinforces the body and web) are titanium alloy parts with a high aspect ratio. These parts occupy the critical load path position of the aircraft and are required for large one-piece construction. This study verifies the milling process and deformation of the chord and side fitting. First, the milling characteristics of the Ti-6Al-4V alloy were simulated and the simulated cutting resistance was verified via comparison with experimental result. Next, the effects of the milling conditions on Ti-6Al-4V cutting resistance and cutting temperature were determined in a Taguchi analysis of the signal-to-noise ratio and variance. Finally, the deformation degrees of the BL0 chord and side fitting were determined using the simulated cutting resistance and cutting temperature.