http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
신동수(Dongsoo Shin),최명환(Myunghwan Choi),Kanmaniraja Radhakrishnan,구자예(Jaye Koo),정승채(Seungchai Jung) 한국추진공학회 2018 한국추진공학회지 Vol.22 No.4
In a spray experiment using a venturi mounted on a lean premixed LPP injector, droplets appear to have non-uniform distributions. To solve this problem, the exit angle of the venturi was changed to form a dump surface on the nozzle neck. The dump surface improved the atomization performance and minimized droplet loss while forming recirculation zone in the venturi exit. In order to solve the non-uniform spray of the injector, the flow characteristics inside the venturi and SMD of the spray are compared. Finally, an optimum venturi shape is selected to minimize the spray loss and improve the spray performance.
신동수(Dongsoo Shin),최명환(Myunghwan Choi),Kanmaniraja Radhakrishnan,박선정(Sunjung Park),구자예(Jaye Koo) 한국추진공학회 2018 한국추진공학회 학술대회논문집 Vol.2018 No.5
예막 공기충돌형 방식의 희박 예혼합 예증발(LPP) 보조 분사기에 축소-확산 노즐인 벤추리를 장착하여 분무 실험을 할 경우 액적의 낙수현상이 나타나며, 이는 액적의 불균일한 분포로 나타난다. 불균일한 액적 분포는 연소 시 점화 지연이 일어날 수 있으며, 연소 중에는 국부적으로 농후한 연소가 일어나면서 NOx의 배출량을 증가시킬 수 있다. 본 논문에서는 벤추리의 축소 노즐만을 이용하였을 때, 보조 분사기의 리세스 길이를 변화하여 분무 형상 및 액적 직경(SMD) 측정 등 분무특성을 확인하였다. 리세스 길이가 감소하면서 분무의 형상은 큰 차이를 보이지 않았지만, SMD는 작아졌다. 리세스 길이에 따른 분무 결과가 가장 좋은 모델을 선정하여 확산부 및 덤프면을 형성시켰으며, 형상에 따른 분무특성을 확인하였다. In a spray experiment with a venturi as converging-diverging nozzle mounted on a lean premixed LPP injector, the droplet appears to have a non-uniform distribution. Non-uniform distribution can lead to ignition delay during combustion, and local combustion can occur during combustion, which can increase NOx emissions. In this paper, spray characteristics were confirmed by changing the recess length of the pilot injector when using only venturi converging nozzles. As the recess length decreased, the shape of the spray did not show much difference, but the SMD decreased. Diffusion and dump surfaces were formed by selecting the best spraying results, and the spray characteristics according to the shape were confirmed.
역추적 기법을 활용한 산업용 유압호스의 가상 물성치 추정
양현모(Hyunmo Yang),구본열(Bonyeol Koo),최명환(Myunghwan Choi),김태환(Taehwan Kim),김재정(Jayjung, Kim) (사)한국CDE학회 2015 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2015 No.동계
Among the various parts which construct hydraulic system, especially hydraulic hoses play important roles in the organic connection between components of hydraulic system and in the efficient power transmission. Therefore, a path design during development process of various industrial machines is one of the important issues. A method using a commercial software based on the virtual reality was proposed to estimate the path of anisotropic hydraulic hoses. Design parameters which are necessary to be input to create paths are materials properties values such as Young"s modulus, shear modulus, and Poisson’s ratio. However, a distance error is occurred between the path on which materials properties are applied and that obtained from actual experiment like tensile test etc. A backward tracing scheme was used in this study to search virtual materials properties which are closest to actual path of horses.