the high temperature fluids in the vicinity of the heated plate and introduce the low-temperature ambient fluids into the region behind the promoters.
The optimum height and the attack angle that make the overall heat transfer coefficients a maximum were determined for the present promoters and they are H=10mm and α=90 degrees, respectively, within the range of the present experiments.
1. Heat transfer enhancement with an inclined semicylindrical turbulence promoter
2. Heat transfer enhancement in a turbulent natural convection boundary layer along a vertical flat plate
Present authors have proposed a unique type of promoter : "V-shaped" is the best.
And they experiment to find adequate "height and angle"
General theoretical sintering temperature is 70% of the melting point
- ZrO2 : Tm – 2700 ℃ sintering temperature - 1890 ℃
- Al2O3 : Tm - 2050 ℃ sintering temperature - 1435 ℃
The actual sintering temperature
- ZrO2 : 1400 ℃
- Al2O3 : 1650 ℃
The alumina has Corundum structure , this is stable transformation of a-Al2O3
rhombohedral
T
Working in the static mode, the bending arises as a consequence of a surface stress change induced by any molecular reaction which takes places on only one of the cantilever surfaces. The induced surface stress change could be positive or negative, depending on the surface deformation generated. The factors and phenomena responsible for this change is today not fully understood due to the complex
1. 서론
1) 연구의 배경
기존 에너지원의 고갈 속에 신재생 에너지는 가장 주목 받는 분야 중 하나이다. 세계 여러 국가가 관련 사업의 비중을 늘려 가고 있으며, 그 효율성 또한 나날이 증가 하고 있다.
최근 에는 건물 자체에 신재생에너지 발전 설비를 탑재하여 건물 소비 전력을 대체 하는
ZEB