【标题】Numerical Study on Cavitation Phenomenon in an In-Line Centrifugal Pump
【参考中译】直列式离心泵内汽蚀现象的数值研究
【类型】 期刊
【关键词】 Cavitation; Cavitation model; Computational fluid dynamics; Flow behaviour; In-Line centrifugal pump
【参考中译】 汽蚀；汽蚀模型；计算流体力学；流动特性；直列式离心泵
【作者】 Md Rakibuzzaman; Sang-Ho Suh; A. K. M. Parvez Iqbal; Hyoung-Ho Kim
【摘要】 Cavitation in pumps causes unwanted consequences, such as noise, vibrations, and system oscillations. These result in reduced pump efficiency and unstable operation range. Therefore, this study investigates the cavitation behaviours of newly designed centrifugal pumps experimentally and numerically. Computational Fluid Dynamics (CFD) was used to analyse cavitation flow behaviours. The Rayleigh-Plesset expression for bubble dynamics was employed to capture the cavitation phenomenon inside the pump. Numerical simulations were performed and validated by experiments, and good performance characteristics were obtained. The estimated total head drop lines for different cavitation flow rates and performances were analysed numerically. Cavitation was observed near the impeller blade suction for the leading-edge condition in impeller flow passage; moreover, a lower pressure was observed near the impeller blade shroud than the hub in the steady-state condition.
【参考中译】 泵中的汽蚀会导致不必要的后果，如噪音、振动和系统振荡。这导致泵的效率降低，运行范围不稳定。因此，本研究对新设计的离心泵的汽蚀行为进行了实验和数值研究。利用计算流体力学(CFD)对空化流动行为进行了分析。气泡动力学的Rayleigh-Plesset表达式被用来捕捉泵内的空化现象。进行了数值模拟并进行了实验验证，获得了良好的性能特性。数值分析了不同空化流量和性能下的估算总水头降线。在叶轮流道的前缘状态下，叶轮叶片吸力附近观察到空化现象，并且在稳态状态下，叶轮叶冠附近的压力低于轮毂附近的压力。
【来源】 International review of mechanical engineering 2022, vol.16, no.3
【入库时间】 2023/6/29
【标题】Machine Learning for Monitoring of the Solenoid Valves Coil Resistance Based on Optical Fiber Squeezer
【参考中译】基于光纤挤压机的电磁阀线圈电阻监测的机器学习
【关键词】 Machine learning; Monitoring; Solenoid valve; Coil resistance; Fiber squeezer
【参考中译】 机器学习；监测；电磁阀；线圈电阻；纤维挤压机
【作者】 Said Amrane; Abdallah Zahidi; Mostafa Abouricha; Nawfel Azami; Naoual Nasser; Mohamed Errai
【摘要】 Solenoid valves represent indispensable elements in various engineering systems. Their failure can lead to unexpected problems. This failure may be caused by fluctuations in the coil resistance of the electromagnetic solenoid (EMS) which actuates these solenoid valves. Hence the need to monitor this parameter for a preventive maintenance of these actuators. The proposed method consists to use supervised machine learning to monitor coil resistance of the EMS valve. The EMS valve is coupled to an optical fiber squeezer which, acts as a force sensor. The solenoid armature applies a mechanical force to the optical fiber and changes the polarization state of the light that travels through the optical fiber and then this force infects the power of the light. A Simulink model is used to determine the open loop system step response. The identification of the system allows obtaining its transfer function, which depends on the parameters of the EMS and in particular on its coil resistance. By varying the coil resistance while fixing the other physical parameters of the EMS, we generate a database whose elements are the coefficients of the transfer function of the solenoid open loop and the electrical resistance of its coil. The generated database is used for training several supervised machine learning models whose predictors are the elements of the transfer function; the response is the coil resistance. The Gaussian process for regression allows to predict the variations of the coil resistance with the smallest relative error although it takes a relatively long time for the training compared to the other models used.
【参考中译】 电磁阀是各种工程系统中不可缺少的元件。他们的失败可能会导致意想不到的问题。这种故障可能是由驱动这些电磁阀的电磁线圈(EMS)的线圈电阻波动引起的。因此，需要监测该参数，以便对这些执行器进行预防性维护。提出的方法包括使用有监督机器学习来监测电磁阀的线圈电阻。EMS阀与光纤挤压器相连，光纤挤压器充当力传感器。螺线管电枢向光纤施加机械力，改变通过光纤的光的偏振状态，然后这种力影响光的功率。利用SIMULINK模型确定开环系统的阶跃响应。系统的识别允许获得其传递函数，该传递函数取决于EMS的参数，特别是其线圈电阻。通过改变线圈电阻，同时固定电磁线圈的其他物理参数，生成了以螺线管开环传递函数系数及其线圈电阻为元素的数据库。生成的数据库用于训练几个有监督的机器学习模型，这些模型的预测器是传递函数的元素；响应是线圈电阻。回归的高斯过程能够以最小的相对误差预测线圈电阻的变化，尽管与使用的其他模型相比，训练所需的时间相对较长。
【来源】 Journal Europeen des Systemes Automatises 2021, vol.54, no.5
【标题】High-Pressure PMAX7 Axial Fan
【参考中译】高压PMAX7轴流风机
【作者】 Lori Dltoro
【摘要】 Multi-Wing introduced the high-pressure PMAX7 axial fan, engineered to deliver increased airflow for power generators, harvesters and large construction equipment. Featuring fewer blades, PMAX7 has a lower profile to fit into tight spaces. Offered in diameters from 47 inches to 63 inches (1200 mm to 1600 mm), these modular fans are available with five- and seven-blade configurations with 26-degree, 31-degree and 36-degree pitch angle options.
【参考中译】 多翼推出了高压PMAX7轴流风扇，旨在为发电机、收割机和大型建筑设备提供更多的气流。具有更少的刀片，PMAX7具有更低的外形，以适应狭窄的空间。这些模块化风扇的直径从47英寸到63英寸(1200 mm到1600 mm)，有五叶和七叶配置，可选择26度、31度和36度俯仰角。
【来源】 OEM Off-Highway 2023, vol.41, no.2
【标题】Experimental performance of a heat pump driven by vapor injection linear compressor
【参考中译】注汽直线压缩机驱动热泵的实验研究
【关键词】 Linear compressor; Vapor injection; Heat pump; Flow distribution
【参考中译】 直线压缩机；蒸汽喷射；热泵；流量分配
【作者】 Zuohang Tang; Xuan Li; Huiming Zou; Mingsheng Tang; Changqing Tian
【摘要】 Aiming to improve the performance of the linear compressor, a prototype of a linear compressor with vapor injection has been developed, and a quasi-two-stage compression heat pump with an intermediate heat exchanger has been established. The influence of key parameters on the flow distribution and performance of the injection linear compressor are experimentally investigated. Under the condition of evaporating temperature of-20℃, condensing temperature of 50℃, the heating capacity of 234 W with COP of 2.06 is achieved. Compared with the non-injection mode, the heating COP of the injection mode increases by 28% on average. The heating COP is affected by the combination of injection pressure and supply power frequency, while the injection mass flow rate is independent of the supply power frequency under the given conditions. As the injection pressure rises, the injection mass flow rate increases linearly. However, there is a special characteristic of the free-piston linear compressor which is different from traditional injection compressors. The injection process has a great effect on the suction process, and the suction mass flow rate decreases with the increasing injection pressure.
【参考中译】 为了提高直线压缩机的性能，研制了一台蒸汽喷射直线压缩机的样机，并建立了带有中间换热器的准两级压缩热泵。通过实验研究了关键参数对直喷式压气机流动分布和性能的影响。在蒸发温度为-20℃，冷凝温度为50℃的条件下，制热量为234W，COP为2.06.与非喷射模式相比，喷射模式的供热系数平均提高了28%。加热COP受喷射压力和电源频率的影响，而在给定条件下，喷射质量流量与电源频率无关。随着注射压力的增加，注射质量流量呈线性增加。然而，自由活塞式直线压缩机具有不同于传统喷射式压缩机的特点。注塑过程对吸气过程影响较大，吸气质量流量随注塑压力的增加而减小。
【来源】 Applied Thermal Engineering 2023, vol.225
【标题】Optimization study on the uniform temperature of an additively manufactured cooler for a semiconductor heating device
【参考中译】半导体加热装置外加式冷却器均匀温度的优化研究
【关键词】 Design optimization; Surrogate model; Cooling device; Uniform temperature distribution; Additive manufacturing; Multi-thermal load region
【参考中译】 设计优化；代理模型；冷却装置；均匀温度分布；附加制造；多热负荷区
【作者】 Seung Yeop Lee; Kun Woo Kim; Da Hye Kim; Min Seok Yang; Ji Wook Kim; Geuna Choi; Jae Wook Lee; Il Seouk Park
【摘要】 A semiconductor heating device is the core component of the apparatus used for testing semiconductor dies. It is important to heat semiconductor dies at a uniform temperature. The surface temperature of the cooler, which is a component of the heating device, directly affects heating temperature uniformity. Thus, a uniform temperature of the cooler enables uniform heating of semiconductor dies. In this study, we developed an optimization method for achieving temperature uniformity in coolers, using an approach based on a surrogate model. The technique developed in this study simplified the conjugate heat transfer in the channel network of a cooler. A body-centered cubic lattice core was adopted for the local augmentation of heat-transfer performance within the internal channel of the cooler. To reveal the effects of the flow speed and lattice column diameter on the pressure drop and heat transfer, a computational fluid dynamics simulation was implemented using a central composite design, with the Reynolds number and diameter ratio varying in the ranges of 3078-23852 and 0.0869-0.313, respectively. The surrogate model was defined after the dimensional analysis of a single channel and circuit analogy. A particle swarm optimization algorithm was adopted to determine the optimal column diameters of each lattice structure based on the surrogate model. The optimization of the cooler of the semiconductor heating device was assessed by comparing it with a model consisting of only identical lattices in each position. The results showed a prominent enhancement, wherein the deviation in the temperature was reduced by 83.4%.
【参考中译】 半导体加热装置是用于测试半导体管芯的设备的核心部件。在均匀的温度下加热半导体芯片是很重要的。冷却器是加热装置的组成部分，其表面温度直接影响加热温度的均匀性。因此，冷却器的均匀温度使得半导体管芯能够均匀加热。在这项研究中，我们开发了一种实现冷却器内温度均匀的优化方法，使用了一种基于代理模型的方法。本研究开发的技术简化了冷却器通道网络中的共轭换热。采用体心立方晶格芯局部强化冷却器内通道内的换热性能。为了揭示流动速度和格子柱直径对压降和换热的影响，采用中心复合设计进行了计算流体力学模拟，雷诺数和直径比分别在3078-23852和0.0869-0.313范围内变化。通过对单通道和电路类比的量纲分析，定义了代理模型。基于代理模型，采用粒子群优化算法确定每种网格结构的最优柱径。通过与每个位置只包含相同晶格的模型的比较，评估了半导体加热装置的冷却器的优化。结果表明，改进后的温度偏差降低了83.4%。
【标题】Guide to gearless and gearbox tuning
【参考中译】无齿轮和变速箱调谐指南
【作者】 Alberto Mantovani
【摘要】 The parameters that manage the final performance of a frequency speed control device (hereafter, inverter) can be divided into four categories. 1. Motor data: lets the inverter know exactly what type of motor it will interface with (e.g., rated power, rated current, poles, no-load current, nominal speed, encoder etc.) and can be found on motor nameplates and data sheets.
【参考中译】 管理频率速度控制装置(下称逆变器)最终性能的参数可分为四类。1.电机数据：让逆变器准确地知道它将与哪种类型的电机接口(例如，额定功率、额定电流、极数、空载电流、额定速度、编码器等)。并可在电机铭牌和数据表上找到。
【来源】 Elevatori 2023, vol.52, no.1