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翅片管式冷凝器的稳态三维分布参数模型与实验验证 总被引:1,自引:1,他引:1
建立了翅片管式冷凝器的稳态三维分布参数模型,用数值计算结果分析了边界条件对冷凝器运行的影响,并用实验验证了模型的准确性.本文所建模型为翅片管式冷凝器的设计和性能优化提供了依据. 相似文献
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Present review paper presents an overall summarised presentational view of the research work to be discussed on the solar still. The current review paper also includes the infused crisis and struggle for obtaining fresh water for drinking purpose and consumption for other household activities which are a result of the ecological imbalance that has prevailed and is in continuation for past many centuries. It also shows the various tested and applied techniques for freshwater production and their suitability in the usability context in the present scenario of the scarcity of clean water. The use of solar desalination technology is discussed elaborately for a broader consumption to be employed in the current and future works. 相似文献
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A camber morphing control fin design and an all-moving control fin design using piezo-composite unimorph actuators are presented in this paper. The control fin of a small flying object is usually actuated using a servo motor system with an electromagnetic motor. Much research has been conducted to solve the structural complexity of servo actuation systems to convert the rotation of a servo motor to a linear actuation motion. To simplify this structural complexity, several types of smart actuators have been developed, such as bimorph or unimorph actuators with piezoelectric material layers and shape memory alloy actuators. In this study, a camber morphing type control fin and an all-moving type control fin actuated using piezo-composite actuators are designed to evaluate their ability to simplify the structural complexity of the gear transmission and electromagnetic servo motor system or hydraulic actuator system. Within the skin of the control fin, a piezo-composite actuator is mounted and the other end inserted in a slot of the control fin. As the piezo-composite actuator is excited by an electric field, the pitch angle of the control fin is changed. Experimental testing for the pitch rotation angle of a control fin in a 450 V electric field showed the deflection angle of the camber morphing control fin was 1.4° and the rotational angle of the all-moving control fin was 5.4°, which is obtained from the rotation angle magnification linkage structural system. 相似文献
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In view of the trend towards higher power densities in ever shrinking geometries, understanding heat spreading fundamentals is gaining importance. In this paper heat spreading in thin longitudinal geometries is considered. This geometry is of practical interest in one-dimensional Cartesian geometries. A characteristic length is derived and it is shown that this has physical significance for the distance that heat spreads, and for the total amount of heat cooled away. Furthermore, it is investigated when “thin” is a viable assumption. The use of the characteristic length is illustrated for the case of a line source cooling to a plate and for the case of the fins of a plate heatsink. The results are compared to numerical simulations. The work is an extension of the authors' earlier work on heat spreading in infinite longitudinal geometries and heat spreading in infinite and finite circular geometries. 相似文献
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以传热学和空气动力学的研究成果为基础,应用正交法设计气缸散热片,并且对空压机以及气缸、气缸盖等温度进行了试验与测量;确认了不同的气缸散热片设计对压缩机的排气温度、气缸盖温度场、气缸温度场以及曲轴箱润滑油温度等各个部分温度的影响是各不相同的;该试验还证实了勃拉休斯关于附面层方程解的科学性。 相似文献
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为提高翅片区域的换热效率、改善板翅式换热器的整体换热性能,提出了一种新型微凸翅片结构。基于结构参数多采样点处的热力学性能仿真结果构建近似模型,以翅片热功率最高为优化目标、压降为约束,使用序列二次规划法确定了微凸体结构参数(微凸高度、微凸夹角、微凸开口长度)的最优值;对微凸体排列间距、排列方式进行优化,确定了改进微凸翅片结构的具体参数值。通过对翅片流道内温度场、压力场分析,以及与相同尺寸的平直翅片的换热性能对比,验证了所提出的新型微凸翅片结构的有效性。 相似文献