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CFD软件广泛用于流体流动与传热的模拟。但CFD软件是一个黑盒子,良好的人机界面、众多参数基于经验值设定以及二次开发知识的相对薄弱,使得软件使用者对于数据流向并非完全清楚,导致模拟过程的盲目性以及模拟结果的差异。模拟结果的准确与否关系到软件的可信度以及软件的推广应用程度。针对如何有效利用当前模拟软件,如何最大限度地发挥其计算性能,并将计算结果精度及可信度进一步提高,提出了一些看法。 相似文献
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我国经济高速、稳定的发展和实力的增强,给我们尽快融入全球经济的大环境创造了前所未有的大好机遇。现在我国处于工业化发展的关键时期,系统吸取发达国家的经验教训,必须从传统工业文明向生态工业文明转变,才能保持可持续发展。所以,党中央,国务院提出的坚持“以人为本,全面、协调、可持续发展”的发展战略是适时的,非常必要的。 相似文献
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NISHI Michihiro 《中国科学:信息科学(英文版)》2010,(1)
A novel double suction shaft-less mini pump was developed for heat control of small energy systems in this study.The mini pump impeller with an exit diameter of 40 mm was combined with the motor rotor supported by the hybrid dynamic bearing.The specific speed of the pump was 125 min-1 m3 min-1 m.The hydraulic performance of the pump was investigated experimen-tally under four rotational speeds.From the test results,it was recognized that the pump could provide a flow discharge of 5 L/min and head of 1.5 m,w... 相似文献
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Ejector can utilize high pressure energy from liquid mechanism,it can be used in heat pump system coupled with economized vapor injection(EVI)scroll compressor.When running under low temperature conditions,the performance of the EVI system with ejector can be improved further.In this paper,the design method of the heat pump system with ejector is presented,and the process for designing the heat pump with ejector(EVIe)was summarized.One prototype heat pump was designed under the condition of the evaporation ... 相似文献
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Potassium humate was extracted from brown coal.A novel super absorbent composite,poly (acrylic acid-co-acrylamide)/potassium humate (PAA-AM/KHA),was prepared by graft polymerization of acrylic acid,acrylamide and coal based potassium humate using N,N'-methylenebisacrylamide as a crosslinker and potassium peroxydisulfate as an initiator.The effects of reaction temperature,degree of neutralization of the poly (acrylic acid) and the amounts of crosslinker,initiator and potassium humate were investigated.Salt resistance tests were also carried out.The composite prepared under optimal conditions had a potassium humate content of 10% and exhibited a water absorption of 770 g/g in distilled water,and 349,286 and 41 g/g in 0.5 mol/L KC1,MgCl2 and AlCl3 solutions respectively.The results indicate that the salt resistance of PAA-AM/KHA was superior to that of poly (acrylic acid-co-acrylamide) because of the collaborative effect of functional groups of the coal based potassium humate.The PAA-AM/KHA micro powder was characterized by IR spectroscopy and the micrographic surface was characterized by scanning electron microscopy.Introduction of potassium humate into the poly (acrylic acid-co-acrylamide) structure creates a composite more suitable for use as a water-managing material in the renewal of arid and desert environments.The salt resisting property of the composite is improved,production costs are reduced and the growth stimulant effect is still present. 相似文献
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Concrete structures in main coal cleaning plants have been rebuilt and reinforced in the coal mines of the Shanghai Da-tun Energy Sources Co. Ltd., the first colliery of the Pingdingshan Coal Co. Ltd. and the Sanhejian mine of the Xuzhou Mining Group Co. Ltd. In these projects, the operating environment and reliability of concrete structures in the main plants of the three companies were investigated and the safety of the structures inspected. Qualitative and quantitative analyses were made on the spe-cial natural, technological and mechanical environments around the structures. On the basis of these analyses, we discuss the long-term, combined actions of the harsh natural (corrosive gases, liquids and solids) and mechanical environments on concrete structures and further investigated the damage and deteriorating mechanisms and curing techniques of concrete structures in the main coal cleaning plants. Our study can provide a theoretical basis for ensuring the reliability of concrete structures in main coal cleaning plants. 相似文献
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根据电容器引线焊接机冲压切边模具中的凸轮设计要求,利用Pro/ENGINEER软件找出凸轮随动件滚子中心的轨迹,通过可变截面扫描间接得到凸轮的三维精确模型。为类似零件的建模提供一种行之有效的方法,并为后续的仿真分析和制造加工提供一种依据。 相似文献