- 허니콤 표면의 마찰계수 특성에 관한 연구 (Part 2 : 마찰계수 급상승현상에 관한 고찰)
- ㆍ 저자명
- 하태웅
- ㆍ 간행물명
- 大韓機械學會論文集
- ㆍ 권/호정보
- 1994년|18권 6호|pp.1439-1447 (9 pages)
- ㆍ 발행정보
- 대한기계학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
Test results of friction-factor for the flow of air in a narrow channel lined with various honeycomb geometries show that, generally, the friction-factor is nearly constant or slightly decreases as the Reynolds number(or Mach number) increases, a characteristic common to turbulent flow in pipes. However, in some test geometries this trend is remarkably different. The friction factor dramatically drops and then rises as the Mach number increases. This phenomenon can be characterized as a "friction-factor jump." Further investigations of the acoustic spectrum indicate that the "friction-factor jump" phenomenon is accompanied by an onset of a normal mode resonance excited coherent flow fluctuation structure, which occurs at Reynolds number of the order of $10^4$. New empirical friction-factor model for "friction-factor jump" cases is developed as a function of Mach number and local pressure.ach number and local pressure.