共查询到18条相似文献,搜索用时 93 毫秒
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油液的雾化直接影响静电涂油机的喷涂质量,通过静电涂油机的油液雾化实验得到了油液雾化过程的主要指标和影响油液雾化质量的主要因素,根据二者之间的关系建立了静电涂油机油液喷射雾化的数学模型。使用V isual C++面向对象技术和开放图形库,根据所建立的数学模型,模拟了不同电压下油液的静电雾化形态。理论分析和实验研究表明:射流长度随电压的升高和刀梁到钢板距离的减小而越小,雾化角随电压的升高和刀梁到钢板距离的减小先增大后减小。对比不同电压下的油液雾化照片,雾化形态模拟图基本实现了静电喷涂中油液雾化的动态过程,达到了预期的仿真目的。 相似文献
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离心雾化器是垃圾发电厂尾气净化的关键设备,其雾化性能直接影响垃圾焚烧尾气排放的质量与吸收剂的利用率.在介绍雾化器工作原理的基础上,建立离心雾化器雾化性能试验系统,分析雾化转盘转速、进料速率、石灰浆液质量分数等参数对雾滴粒径分布和喷雾距的影响.试验结果表明:雾化转盘转速提高,雾滴粒径和喷雾距减小,当雾化转盘转速提高到某一... 相似文献
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(1)喷油器雾化不良喷油器的雾化程度直接影响柴油机气缸内的燃烧质量.喷油器喷出的柴油雾化质量不高,有的慢泵不雾化,快泵有部分雾化,有的干脆不雾化,并有滴油现象,还有就是喷油压力没有达到出厂压力,这些都会引起柴油机燃烧不完全,从而产生冒黑烟现象. 相似文献
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针对喷嘴在喷胶过程中产生堵塞问题,设计一个二流体新型喷嘴,根据相关资料确定喷嘴的结构和主要尺寸.采用Fluent软件模拟不同压力下的喷嘴的内流场雾化及喷射流场.仿真结果表明:内流场雾化过程中,在不同空气压力下SMD变化趋势均为下降.喷射流场雾化过程中,在不同空气压力下SMD变化趋势均为先增加后不变,再减小后不变,雾化粒径小且一致,散布均匀,有利于胶液充分雾化,为工程优化设计提供了基础. 相似文献
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针对喷嘴在喷胶过程中产生堵塞问题,设计一个二流体新型喷嘴,根据相关资料确定喷嘴的结构和主要尺寸.采用Fluent软件模拟不同压力下的喷嘴的内流场雾化及喷射流场.仿真结果表明:内流场雾化过程中,在不同空气压力下SMD变化趋势均为下降.喷射流场雾化过程中,在不同空气压力下SMD变化趋势均为先增加后不变,再减小后不变,雾化粒径小且一致,散布均匀,有利于胶液充分雾化,为工程优化设计提供了基础. 相似文献
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高品质金属粉末是众多制造领域中的基础材料,微细粉末成型的关键技术在于气雾化制备阶段,而喷嘴及导液管结构和雾化工艺参数对气雾化粉末的质量有重要影响。基于高速射流流体动力学的数值模拟方法研究了雾化压力、雾化气体温度、导液管下口直径与伸出长度对配备下限流导液管环缝喷嘴雾化能力的影响,通过喷盘流场检测验证模型的可靠性。结果表明:环缝喷嘴装配下限流导液管临界入口压力为128.1 kPa,雾化压力2.0 MPa时既能有效增大雾化腔内的气体最大速度和降低最低温度,又能防止过高压力造成返喷而影响气雾化顺行。此外,在极限雾化压力2.0 MPa下,通过增大雾化气体温度、下限流导液管下口直径由5 mm降低至1 mm以及伸出长度由0 mm增大至2 mm均能继续提升气液质量流速比而提升其雾化能力。生产实践也证实了模型的预瞻性,在此优化工艺下生产顺行且粉末粒度D50仅为23.84μm。 相似文献
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Swirl effect on the spray characteristics of a twin-fluid jet 总被引:1,自引:0,他引:1
Byung-Joon Rho Shin-Jae Kang Je-Ha Oh Sam-Goo Lee 《Journal of Mechanical Science and Technology》1998,12(5):899-906
In the liquid fuel combustion chamber, employed fuel must be atomized before being injected into the combustion zone. Therefore,
the complete fuel atomization is the most important condition for the combustion efficiency. The atomization quality strongly
affects the combustion performance, exhaust pollutant emissions, and flame stability. Therefore, the whole process of spray
atomization is of fundamental significance. During past decades many experimental and theoretical studies in this field have
been carried out and some improved results have been obtained. Two-phase atomizers, having a variety of advantages such as
spray uniformity, appreciable atomization, and smaller SMD with an increase of ambient gas, are considered to be applied in
various industrial processes. The purpose of present study is to investigate the mean velocity, turbulence shear stress, turbulence
intensity, mean drop size distribution, and droplet data rate in a two-phase swirling jet using PDPA systems. 相似文献
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The combustion process of a coal/oil slurry begins by atomization of the slurry. This project is a presentation of experimental system and results on atomization of coal/oil(COM) and coal/methanol mixtures with a twin-fluid and a wheel atomizer. The slurries are consisted of coal/methanol and coal/oil mixtures with two different concentrations and two coal particile sizes. The volume median diameters of the coal particles were 45 and 130 microns. The oil was No. 2 diesel oil. The droplet size was determined by photographing the spray and the photographs were analyzed to determine droplet size and distribution. The results show that the inclusion of particles in the liquid(both methanol and diesel oil) does not appreciably affect the atomized droplet size. The tendency is for the slurry droplets to be somewhat smaller than the droplets atomized with the pure liquid. 相似文献
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为检测液体雾化状态,基于声发射检测技术,通过采集雾化液体撞击挡板产生的声发射信号,结合功率谱分析、小波分析和重标极差分析,得到雾化液体撞击挡板产生声信号的机理和特征,获得表征液体雾化状态的特征声信号尺度(J1尺度)。根据特征信号尺度能量分率与液体雾化状态间的规律性变化关系,提出雾化质量的判断方法,即液体雾化质量随特征信号尺度能量分率的增大而提高,当特征信号尺度能量分率快速上升时,液体进入充分雾化状态。判断方法得到照相法的验证。利用声发射检测发现液体雾化质量随轴向距离增大而提高,与事实相符。由此获得一种快速、实时、便捷和安全的液体雾化状态检测方法,其可用于雾化机理研究、喷嘴设计选型和工业生产监控。 相似文献
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The atomizer with micro cone apertures has advantages of ultra-fine atomized droplets, low power consumption and low temperature rise. The current research of this kind of atomizer mainly focuses on the performance and its application while there is less research of the principle of the atomization. Under the analysis of the dispenser and its micro-tapered aperture’s deformation, the volume changes during the deformation and vibration of the micro-tapered aperture on the dispenser are calculated by coordinate transformation. Based on the characters of the flow resistance in a cone aperture, it is found that the dynamic cone angle results from periodical changes of the volume of the micro-tapered aperture of the atomizer and this change drives one-way flows. Besides, an experimental atomization platform is established to measure the atomization rates with different resonance frequencies of the cone aperture atomizer. The atomization performances of cone aperture and straight aperture atomizers are also measured. The experimental results show the existence of the pumping effect of the dynamic tapered angle. This effect is usually observed in industries that require low dispersion and micro- and nanoscale grain sizes, such as during production of high-pressure nozzles and inhalation therapy. Strategies to minimize the pumping effect of the dynamic cone angle or improve future designs are important concerns. This research proposes that dynamic micro-tapered angle is an important cause of atomization of the atomizer with micro cone apertures. 相似文献
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低压燃油雾化喷嘴流动能量损失特性数值研究 总被引:1,自引:0,他引:1
建立了描述燃油在有渐扩切向槽的低压燃油喷嘴内的三维流动数学模型,采用SIMPLE算法进行计算,探讨低压下这种喷嘴的流动阻力特性,并采用试验方法研究了低压下油的雾化特性,以确定优化的燃油雾化喷嘴的结构特性。结果表明:在θ= 6o左右时,燃油雾化喷嘴出口流体的回流卷吸作用消失;在低压下(p0=0.8 Mpa),当燃油雾化喷嘴的结构特征为n=3~4,L≤2.5,θ=5o~6o,a/b=1.2和Rx/rb≥2.5时,能量损失达到最小,喷嘴压降达到最低;结构优化的燃油雾化喷嘴在低压下可保持良好的雾化质量。研究得到的燃油雾化喷嘴可用于火电厂、化工及建材等燃烧动力装置的燃烧点火及助燃等。 相似文献
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高速电弧喷涂3Cr13钢雾化粒子温度和飞行速度数值模拟 总被引:1,自引:1,他引:1
用二相流流体动力学和空气动力学理论建立了高速电弧喷涂雾化粒子温度和飞行速度的数学模型,通过引入高速电弧喷涂工艺过程的送丝速度、丝材直径、喷涂电流、电压和雾化气体压力等工艺参数,与雾化微滴温度、飞行速度和粒度分布建立联系,揭示了高速电弧喷涂工艺参数对雾化过程微滴物理特性的影响。数值分析结果表明,3Cr13钢微滴速度在实际喷涂距离范围内变化不大;粒度对微滴初始温度有较大影响;不同粒度微滴的过热度在1 320~2 090 K之间,电阻项对微滴过热度的贡献最大;微滴强烈过热是电弧喷涂材料损耗的主要原因之一。所建立的模型的数值模拟结果与试验结果吻合较好。模拟计算的高速电弧喷涂技术喷涂3Cr13钢的质均粒度和实测的相吻合,但粒度分布特征不同。 相似文献