共查询到8条相似文献,搜索用时 0 毫秒
1.
Xia Jiliang Xin Mingdao Zhang Hongji 《保鲜与加工》1989,(5):20-26
A numerical analysis is carried out for the unsteady and steady, two-dimensional, laminar natural convection heat transfer in a square partial cavity. The partial cavity consists of two horizontal adiabatic surfaces, a vertical hot surface and a cold surface with varied opening. The results are obtained for Ra = 10~3-10~6 and Y0 = 0.0-1.0. This study shows that the opening size has significant effect on the flow and heat transfer in partial cavity, and the. extent of its effect changes with different Rayleigh numbers. 相似文献
2.
Lin Chengxian Xin Mingdao Zhang Hongji 《保鲜与加工》1991,(6):1-7
A numerical study is carried out for the combined heat transfer of turbulent natural convection and surface radiation in an two-dimensional open square cavity with only one heated wall. The results show that the radiation significantly affects the velocity and temperature fields,and it can reduce the turbulent natural convection heat transfer as well as enhance it. For different Rayleigh number and temperature difference ratio,the overall heat transfer rates and the portion of radiation present different variation patterns. 相似文献
3.
Numerical analysis is made for the unsteady and steady, two-dimensional laminar natural convection in an enclosure caused simultaneously by the external heating and a local internal heat source. The velocities and temperature profiles are given, the average and local Nusselt numbers for the hot and cold surfaces obtained, and the equivalent relative intensity of the internal heat source, the critical equivalent relative intensity of the internal heat source and the transient control regime defined. The results show that there exist five flow patterns with changing the external or internal Rayleigh number, and the heat transfer performance for each flow pattern region is different. 相似文献
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5.
Du Yang Xin Mindao 《保鲜与加工》1989,(6):33-39
An experimental study was carried out for the condensation heat transfer on the three dimensional extended surface tube attached by a porous drainage strip. The results show that the combination of the three dimensional extended surface and the porous drainage strip is the effective method enhancing condensation heat tiansfer on the horizontal tube. The change of the shape arid depth of the axial grooves results in a 10% vaitation of condensation heal transfer coei ficienls. In the range of the experiments, for aocohol as the working fluid, the enhancement is up to 152%, and for water, 185% as compared with the horizontal low-finned tube. 相似文献
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Xia Jiliang Xin Mingdao Fu Min 《保鲜与加工》1992,(5):31-37
Flow and heat transfer are numerically studied in a rectangular fin groove when the fin base is heated with contsant temperature. Rayleigh number, inclination , aspect ratio, thick ness and conductivity of the fin are systematically changed to examine their effects. Five flow patterns are found, local and average characteristics are given, and the mechanism of heat transfer is discussed. The results can be used as a reference for fin designs. 相似文献
8.
Jiang Yong 《保鲜与加工》1993,(4)
This paper presents the style and features of Yinchuan with a long history and culture,and analyses the relations between protection of the city and the modernization of the city. 相似文献