지원사업
학술연구/단체지원/교육 등 연구자 활동을 지속하도록 DBpia가 지원하고 있어요.
커뮤니티
연구자들이 자신의 연구와 전문성을 널리 알리고, 새로운 협력의 기회를 만들 수 있는 네트워킹 공간이에요.
이용수
초록· 키워드
오류제보하기
Many studies of heat transfer on the swirling flow or unswirled flow in a abrupt pipe expansion are widely carried out. The mechanism is not fully found evidently due to the instabilities of flow in a sudden change of the shape and appearance of turbulent shear layers in a recirculation region and secondary vortex near the corner.
The purpose of this study is to obtain data through an experimental study of the swirling flow and heat transfer downstream of an abrupt expansion in a circular pipe with uniform heat flux.
Experiments were carried out for the turbulent flow and heat transfer downstream of an abrupt circular pipe expansion. The uniform heat flux condition was imposed to the downstream of the abrupt expansion by using an electrically heated pipe. Experimental data are presented for local heat transfer rates and local axial velocities in the tube downstream of an abrupt 3:1 & 2:1 expansion.
Air was used as the working fluid. In the upstream tube, the Reynolds number was varied from 60,000 to 120,000 and the swirl number range (based on the swirl chamber geometry, i.e. L/d ratio) in which the experiments were conducted were L/d=0, 8 and 16.
Axial velocity increased rapidly at r/R=0.35 in the abrupt concentric expansion turbulent flow through the test tube in unswirled flow. It showed that with increasing axial distance the highest axial velocities move toward the tube wall in the case of the swirling flow abrupt expansion.
A uniform wall heat flux boundary condition was employed, which resulted in wall-to-bulk temperatures ranging from 24℃ to 71℃. In swirling flow, the wall temperature showed a greater increase at L/d=16 than any other L/d. The bulk temperature showed a minimum value at the pipe inlet, it also exhibited a linear increase with axial distance along the pipe.
As swirl intensity increased, the location of peak Nu numbers was observed to shift from 4 to 1 step heights downstream of the expansion.
This upstream movement of the maximum Nusselt number was accompanied by an increase in its magnitude from 2.2 to 8.8 times larger than fully developed tube flow values.
The purpose of this study is to obtain data through an experimental study of the swirling flow and heat transfer downstream of an abrupt expansion in a circular pipe with uniform heat flux.
Experiments were carried out for the turbulent flow and heat transfer downstream of an abrupt circular pipe expansion. The uniform heat flux condition was imposed to the downstream of the abrupt expansion by using an electrically heated pipe. Experimental data are presented for local heat transfer rates and local axial velocities in the tube downstream of an abrupt 3:1 & 2:1 expansion.
Air was used as the working fluid. In the upstream tube, the Reynolds number was varied from 60,000 to 120,000 and the swirl number range (based on the swirl chamber geometry, i.e. L/d ratio) in which the experiments were conducted were L/d=0, 8 and 16.
Axial velocity increased rapidly at r/R=0.35 in the abrupt concentric expansion turbulent flow through the test tube in unswirled flow. It showed that with increasing axial distance the highest axial velocities move toward the tube wall in the case of the swirling flow abrupt expansion.
A uniform wall heat flux boundary condition was employed, which resulted in wall-to-bulk temperatures ranging from 24℃ to 71℃. In swirling flow, the wall temperature showed a greater increase at L/d=16 than any other L/d. The bulk temperature showed a minimum value at the pipe inlet, it also exhibited a linear increase with axial distance along the pipe.
As swirl intensity increased, the location of peak Nu numbers was observed to shift from 4 to 1 step heights downstream of the expansion.
This upstream movement of the maximum Nusselt number was accompanied by an increase in its magnitude from 2.2 to 8.8 times larger than fully developed tube flow values.
목차
Abstract
1. 서론
2. 실험장치 및 방법
3. 결과 및 고찰
4. 결론
5. 참고문헌
참고문헌 (0)
참고문헌 신청함께 읽어보면 좋을 논문
논문 유사도에 따라 DBpia 가 추천하는 논문입니다. 함께 보면 좋을 연관 논문을 확인해보세요!
-
Prediction of Turbulent Heat Transfer in Swirling Flow Downstream of an Abrupt Pipe Expansion
KSME International Journal
1997 .10
-
CALCULATION OF TURBULENT HEAT TRANSFER IN SWIRLING FLOW DOWNSTREAM OF AN ABRUPT PIPE EXPANSION
KSME/JSME THERMAL and FLUID Engineering Conference
1996 .10
-
선회류를 동반한 급확대 원관내에서의 열전달 특성에 관한 실험적 연구 ( An Experimental Study of the Swirling Flow and Heat Transfer Downstream of an Abrupt Expansion in a Circular Pipe with Uniform Heat Flux )
Journal of Advanced Marine Engineering and Technology (JAMET)
1994 .11
-
원관내 급확대부 하류의 강선회난류에 관한 수치해석
설비공학논문집
1997 .02
-
Prediction of Turbulent Heat Transfer Downstream of an Abrupt Pipe Expansion
KSME International Journal
1994 .09
-
확대관내의 난류선회류에 대한 수치해석 ( Calculation of Swirling Turbulent Flows Downstream of an Abrupt Pipe Expansion )
대한기계학회 춘추학술대회
1995 .01
-
균일 열플럭스가 있는 급팽창 확대관내에서의 난류선회유동에 관한 연구 ( An Experimental Study of the Swirling flow and Heat Transfer Downstream an Abrupt Expansion in a Circular Pipe with Uniform Heat Flux )
대한기계학회 춘추학술대회
1993 .01
-
An Experimental Study on Swirling Flow with Heat Transfer in the Horizontal Circular Annuli
Journal of Advanced Marine Engineering and Technology (JAMET)
2005 .05
-
An Investigation of Heat Transfer Characteristics of Swirling Flow in a 180˚Circular Section Bend with uniform Heat Flux
Journal of Mechanical Science and Technology
2003 .10
-
Experiments on Swirling Flow in a Vertical Circular Tube
대한기계학회 춘추학술대회
2011 .05
-
An Experimental Study on Heat Transfer Characteristics with Turbulent Swirling Flow Using Unform Heat Flux in a Cylindrical Annuli
Journal of Mechanical Science and Technology
2003 .12
-
Experimental Studies on Swirling Flow in a Vertical Circular Tube
Journal of Advanced Marine Engineering and Technology (JAMET)
2011 .11
-
(초청강연) PIV 기법을 이용한 선회유동의 급팽창에 관한 실험적 연구
대한기계학회 춘추학술대회
2008 .10
-
3D PIV 기법을 이용한 선회유동의 급팽창에 관한 실험적 연구
Journal of Advanced Marine Engineering and Technology (JAMET)
2009 .03
-
An Experimental Study on Swirling Flow in a Vertical Circular Pipe
한국가시화정보학회 학술발표대회 논문집
2010 .11
-
Experimental Study on Heat Transfer with Swirling Flow in a Cylindrical Annuli
한국가시화정보학회지
2010 .03
-
Velocity and temperature profiles of Al/water micro fluid in a circular tube with swirl
Journal of Advanced Marine Engineering and Technology (JAMET)
2013 .11
-
A STUDY ON SWIRLING FLOW AND HEAT TRANSFER CHARACTERISTICS IN A 180` CIRCULAR BEND WITH UNIFORM HEAT FLUX
KSME/JSME THERMAL and FLUID Engineering Conference
1996 .10
-
수평 원통관내에서 Swirling Flow의 유동에 관한 연구(Ⅰ)
설비공학논문집
1989 .11
-
수직원통관에서 선회유동의 속도분포에 관한 연구
한국가시화정보학회지
2011 .09
이 논문의 저자 정보
최근 본 자료
댓글(0)
0
UCI(KEPA) : I410-ECN-0101-2009-559-015521749