共查询到19条相似文献,搜索用时 62 毫秒
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基于射流振荡基础的流量传感器的结构原理、主要技术特征、流量测量特征以及传感与信号处理技术.针对射流流量传感器的流量测量特性,提出降低射流计量腔的起振阈值,改进电磁传感原理检测射流振荡信号的方法. 相似文献
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通过仿真和用 5 0mm直径卡曼涡街流量计进行实验验证 ,得出 :双钝体组合能够增强流体振动 ,并且在钝体的轴对称点上存在相位相差 180°的流体振动点。采用双钝体组合结构和差动传感技术 ,能够研制出抗干扰性能良好和高灵敏度的新型涡街流量计。 相似文献
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使用PIV技术测量喷嘴附壁射流的冷态流场 总被引:2,自引:0,他引:2
对扁平火焰燃烧器的喷嘴布置方式进行了研究,采用粒子图像测速技术(PIV)对喷嘴附壁射流流场进行测量,探讨不同的斜面角度和喷嘴喷射角度对流场的影响,为这种燃烧器的设计提供了数据依据。 相似文献
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电容式靶式流量计的研究与仿真 总被引:1,自引:0,他引:1
阐述了电容式靶式流量计的工作原理,设计了基于MSP430F149单片机的电容式靶式流量计的硬件和软件.采用IAPWS-IF97水蒸汽公式进行密度补偿,克服了传统水蒸汽密度补偿方法不能适应工况大范围变化和不能满足精度要求的缺陷,提高了测量的精度.采用FLUENT数值仿真软件模拟圆盘形、圆锥形、球形等3种靶片的受力、流体流经靶片的压力损失与被测流体质量流量之间的关系,为工程应用中靶片形状的选择提供理论依据. 相似文献
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WANG Yu HE Pingting YE Hong XIN Zhihong 《机械工程学报(英文版)》2007,20(5):42-45
Instantaneous flow field and temperature field of the two-phase fluid are measured by particle image velocimetry (PIV) and steady state method during the state of onflow. A turbulent two-phase fluid model of stirred bioreactor with punched impeller is established by the computational fluid dynamics (CFD), using a rotating coordinate system and sliding mesh to describe the relative motion between impeller and baffles. The simulation and experiment results of flow and temperature field prove their warps are less than 10% and the mathematic model can well simulate the fields, which will also provide the study on optimized-design and scale-up of bioreactors with reference value. 相似文献
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在天津大学电气与自动化工程学院流量实验室的气体流量试验装置上,通过改变管道内气体的压力,对涡街流量传感器的压力损失系数进行试验研究。对大量试验数据进行处理后发现,涡街流量传感器的压力损失系数会随着管道内气体压力的变化而有所变化。当管道内气体压力在0.1~1.1 Mpa的范围内变化时,压力损失系数会随着气体压力的增大而减小,变化幅度最大达到了7%。对压力损失系数随气体压力变化的规律进行分析,并给出压力损失系数随管道内气体压力变化的计算公式。 相似文献
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广义脉码调制(GPCM)控制阀是一种组合形式的阀,各基元通过液压集成块连接到一起。流体在液压集成块流道内的运动分布规律是研究液压阀流量控制的关键之一,它决定了GPCM控制阀流量控制的精确度。对GPCM控制阀内部的压力与流量之间的关系进行理论研究,并对它进行了流场的仿真研究,得到了阀节流口压力变化与基元流量之间的关系。研究结果有助于GPCM控制阀时使结构优化设计,使GPCM控制阀具有较好的流量控制精度。 相似文献
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NUMERICAL SIMULATION AND EXPERIMENTAL STUDY OF A KIND OF LOCAL EXHAUST VENTILATION HOOD 总被引:1,自引:0,他引:1
He SuyanSchool of Dynamic andMechanical Engineering Shanghai Jiaotong University Shanghai ChinaLi YunfeiSchool of Agriculture Biology Shanghai Jiaotong University Shanghai China 《机械工程学报(英文版)》2003,16(4):433-436
A new local exhaust ventilation hood is presented. First, the test system in laboratory roomis established. Secondly a mathematical model is developed in terms of the stokes stream function, andthe governing equation is solved using finite-difference techniques. The injection flow of the exhausthood is treated as a boundary condition of the main flow. Experiments results well agree with thesolution of theoretical prediction. The model can, therefore, be used to design this kind of Aaberg hood. 相似文献
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Three-dimensional numerical simulations are carried out to investigate the temperature field in the contact zone due to the thermal loading of the workpiece in surface grinding. This technique considers that the thermophysical properties of the workpiece material are non-linear according to temperature, the contact zone between the wheel and the workpiece is assumed as an arc surface, and the heat flux entering the workpiece is assumed as proportional to the local undeformed chip thickness. A good agreement is found between the simulated results and the experimental observations. The high grinding temperature leads to the thermal expansion of the workpiece material, which causes the thickness of the actual material removal layer to be larger than the cutting depth. The grinding temperature at the central portion is higher than that on the side of the workpiece during the wet grinding, thus the material removal layer in the central zone is thicker than that on the side zone, and the workpiece surface is concave across the grinding width. 相似文献