http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Flow and Oxygen-Transfer Characteristics in an Aeration System Using an Annular Nozzle Ejector
Park, Sangkyoo,Yang, Heicheon American Chemical Society 2013 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.52 No.4
<P>This paper is aimed at the investigation of flow and oxygen-transfer characteristics in an aeration system using an annular nozzle ejector, and the experimental evaluation of the oxygen-transfer characteristics in the ejector aeration and blower aeration. The entrainment ratio decreased with the primary water flow rate of the annular nozzle ejector, with ratios ranging between 6.8 and 0.4. It was found that the turbulence level and entrainment ratio strongly affected the air bubble size and the volumetric mass-transfer coefficient. The saturation times and volumetric mass-transfer coefficients varied with the suction air flow rate in the ejector aeration, while the times decreased and the coefficients increased with the blowing air flow rate in the blower aeration. The average mass-transfer coefficient of the ejector aeration was about 3.7 times higher than that of the blower aeration. It was found that the high turbulence level and optimum entrainment ratio were needed to increase the oxygen-transfer rate.</P>
전용권(Yonggwon Jeon),박흥근(Heungkeun Park),이상규(Sangkyoo Lee),안영동(Yeongdong An) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12
Accuracy and calculation efficiency of vibration fatigue analysis in time domain are related to two major factors, the size of FE model and load data. If one can handle massive size of data easily, it can be the best case. However, handling a massive data is impractical and laborious in simulation environment. Thus, the size of FE model or load data must be reduced to reflect dynamic characteristics of massive size of data in the view of efficiency and suitability. This paper presents a new method of signal extraction technique, for ground vehicle (an excavator, a wheel loader, etc.), considering the statistical characteristics and fatigue damage equivalency. The extracted load data, with shorter time duration, satisfy statistical properties with respect to the original data.