NUMERICAL INVESTIGATIONS OF FORCED CONVECTION FROM RECTANGULAR COILED PIPES
Investigations are done to numerically study forced convective heat transfer from the flow inside a rectangular coiled pipe, as micro-scale heat exchange device with staggered arrangement, to the external flow around the pipe. The commercial CFD software Fluent 6.0 is used as the solver. The problems considered were three-dimensional laminar flow of the refrigerant R141B through the tube and turbulent air flow exterior to the tube. The studied coiled pipe was composed of four rows among which two rows were encompassed in a large rectangular coil and the other two were in an inner smaller rectangular coil. The results showed remarkable differences in the flow behavior and heat transfer for different rows of tubes. The secondary flow in the tubes bends of the larger rectangular coil is very weak compared to that of the inner rectangular coil. Better heat transfer process occurred through the tubes of the second row where the higher values of the fluid temperatureswere observed in the pipe. The results showed the effects of the straight tubes inclination angle on the flow behavior in rectangular coiled pipes. The shape of the secondary flow is changed from a couple of vortices in the case of smaller angle (α =9 o ) to a single vortex in the case of larger angle (α =45 o ). The results also showed the rotation of the maximum axial velocity due to the increase in the straight tubes inclination angles. The results are in good agreement with previous numerical and experimental works on laminar flow in helical coil pipe.
Ibrahima Conté Xiao-Feng Peng Zhen Yang
Laboratory of Phase-Change and Interfacial Transport Phenomena, Tsinghua University, Beijing 100084, China
国际会议
海南三亚
英文
2007-01-10（万方平台首次上网日期，不代表论文的发表时间）