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柴油闪急沸腾喷雾的试验研究 被引量:2
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作者 段树林 冯林 +1 位作者 许锋 周经纬 《大连铁道学院学报》 1997年第1期57-60,共4页
通过对柴油机高压油管进行外加热源加热,在E150柴油机上实现了柴油的闪急沸腾喷雾,并对柴油机的性能及排放进行了试验研究。结果表明,采用闪急沸腾喷雾,柴油机油耗可降低8g/kW·h,烟度下降0.4BSU,NOX排放... 通过对柴油机高压油管进行外加热源加热,在E150柴油机上实现了柴油的闪急沸腾喷雾,并对柴油机的性能及排放进行了试验研究。结果表明,采用闪急沸腾喷雾,柴油机油耗可降低8g/kW·h,烟度下降0.4BSU,NOX排放略有升高,CO,HC排放均降低。 展开更多
关键词 柴油机 柴油 燃烧试验 闪急沸腾喷雾
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TGO的生长厚度对热障涂层失效机理的应力分析
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作者 朱梦颖 《贵阳学院学报(自然科学版)》 2021年第2期65-72,共8页
热障涂层是在高温合金表面涂覆一层低热导率的陶瓷层,将金属材料的高强度、高韧性和陶瓷材料的隔热性结合起来的涂层系统,已经在航空、航天以及船舶等行业得到了广泛应用。热障涂层为复合结构,陶瓷层的剥落失效是阻碍其发展应用的最主... 热障涂层是在高温合金表面涂覆一层低热导率的陶瓷层,将金属材料的高强度、高韧性和陶瓷材料的隔热性结合起来的涂层系统,已经在航空、航天以及船舶等行业得到了广泛应用。热障涂层为复合结构,陶瓷层的剥落失效是阻碍其发展应用的最主要因素。热障涂层的失效由众多因素共同作用造成,在多因素共同作用下涂层内部产生复杂应力场,涂层在复杂应力场的作用下剥落失效。因此,研究不同因素作用下热障涂层的应力场分布特征具有重要的意义。本文基于热障涂层结构建立了有限元模型,在充分考虑蠕变的基础上,研究热障涂层自身的因素TGO热生长氧化物厚度对其内部应力场分布及应力水平的影响规律。基于应力分布特征,TGO厚度对热障涂层的失效模式起到控制性的作用;基于应力水平分析结果,影响较为显著。 展开更多
关键词 热障涂层 应力场分析 TGO厚度 等离子喷涂
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Monocular vision for variable spray control system
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作者 Daozong Sun Weikang Liu +7 位作者 Runmei Luo Xurui Zhan Zehong Chen Tao Wei Xinrui Wang Xiuyun Xue Zhen Li Shuran Song 《International Journal of Agricultural and Biological Engineering》 SCIE CAS 2022年第6期206-215,共10页
The monocular vision-based system can obtain the leaf wall area characterizing the canopy parameter for online detection and real-time variable spraying,aiming to improve the accuracy of orchard spraying equipment and... The monocular vision-based system can obtain the leaf wall area characterizing the canopy parameter for online detection and real-time variable spraying,aiming to improve the accuracy of orchard spraying equipment and the utilization efficiency of pesticide.This study established a spraying system,in which canopy parameters were collected by monocular vision,and the spray volume decision coefficient was constructed by the leaf wall area and the L^(*)value in International Commission on Illumination Lab color space to control the duty cycle of each solenoid valve to achieve variable spraying.Four spray flow models were designed to determine the spray volume decision coefficient.The coefficients of determination of the spray volumes with the duty cycle range of 15%to 65%were all over 94 and the error of the leaf wall area values obtained using the improved super green algorithm(calculated as ExG=2.1G–1.1R–1.1B)was only 0.5%.The test showed that there is a negative relationship between canopy denseness and L^(*),and the value of L^(*)is smaller in the dense area compared with the sparse area;the actual flow generated by the system is similar to the theoretical flow when the duty cycle is 65%.The field validation tests showed that the variable spraying system could refine the droplet size and increase the droplet density to a certain extent with the same coverage rate,which had advantages over the continuous spraying.In terms of droplet deposition,DV0.1 and DV0.9 were reduced by 2μm and 18μm,respectively,and the increase of droplet density to 75 droplets/cm2.At the same time,the improvement of droplet distribution uniformity and droplet penetration by 16%and 3%,respectively.Compared with continuous spraying,variable spraying can achieve 55.64%savings.The study demonstrates the feasibility of monocular vision in guiding spraying operations and provides a reference for the use of monocular vision in plant protection operations. 展开更多
关键词 monocular vision leaf wall area Lab color space pulse width modulation variable sprayi
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