计算多轴拌器的轴功率

对三种搅拌器：锚式、螺旋式、锯齿式，在不同的转速配比下进行了轴功率测试，搅拌雷诺数为０．８～３０００００，液体的粘度为０．００１～８４Ｐａ．ｓ。液体的性质属牛顿型流体，试验过程用计算机控制．通过测量轴的扭矩来确定搅拌器的轴功率。实验测定了不同情况下搅拌器相互之间的影响。实验数据由马跨特计算方法确定模型参数并给出层流至湍流范围内三种搅拌器轴功率的计算公式．     

风力发电机叶片变桨距偏离方式的受力分析

通过叶素理论及贝茨理论对两种风机叶片桨距角调节方法进行了对比,系统分析叶片桨距角偏离所引起的受力、边界层分离、攻角及桨距角等参数的变化,计算出叶片升力/阻力变化;通过求解流体边界层方程,揭示出叶片偏离最优桨距角之后产生的实际变化。得到下述结论:桨距角变大时,风机效率变化稳定但变化慢,桨距角调节范围较大;桨距角变小时,风机效率变化敏感,调整范围需要精密控制;该结论可为不同应用区域风机叶片参数调整方式的确定提供参考。     

基于Cimatron E的螺旋桨整体四轴加工技术研究

介绍了三桨叶的整体式船用螺旋桨四轴加工方法,运用Cimatron E软件对螺旋桨叶片进行四轴刀位轨迹的生成。通过数字化的软件对其进行造型并加工,大大提高了螺旋桨的加工效率,为大扭曲复杂型面的螺旋桨的加工制造提供了参考。     

Dynamic hydroelastic scaling of self-adaptive composite marine rotors

The objective of this work is to establish dynamic similarity relationships for self-adaptive composite marine rotors. Although scaling laws are well established for rigid propellers and turbines, relative little work has been shown for flexible marine rotors that are designed to interact with the surrounding flow. Considering recent interests in the development of large-scale, energy-efficient composite marine propellers and turbines, it is crucial to understand the scaling relationships to properly design and interpret model-scale studies. Explanations of the similarity requirements are presented, along with scaling factors for the various fluid and structural parameters that control the dynamic interactions between the flexible rotor and the surrounding flow. Finally, numerical results obtained using a fully coupled, three-dimensional, boundary element method–finite element method is shown to demonstrate the validity of theoretical scaling relationships and to investigate scaling effects. The results suggest that for most marine rotors where gravitational forces are negligible compared to other dominant forces and the boundary layer is fully turbulent, it is most practical to conduct model-scale experiments to satisfy Mach number similarity, even though the Mach number will be much less than one for most marine applications.     

浅谈提高大中型轴流泵装置效率

该文根据影响中、小型轴流泵装置效率的因素，提出提高中、小型轴流泵装置效益的技术措施。实践证明，只要认真落实轴流泵站的各项节能措施，提高泵站的装置效率，使其达到部颁标准，是完全可以实现的。     

船舶螺旋桨用不锈钢的发展

概述了船舶螺旋桨用不锈钢的发展 ,给出了几种性能优良的不锈钢螺旋桨材料 ,阐述了不锈钢作为螺旋桨材料的优缺点。     

设计凿岩钻车液压平移机构的新方法

本文提出了把支臂在拐点角位置时的推进器设计成水平。把油缸行程平均分配在拐点角位置两侧的设计新方法,可实现断面中部的孔向与巷道纵向轴线的偏差和两相邻炮孔的平行误差同时为最小。     

基于CFD的螺旋桨敞水性能数值分析与验证

根据螺旋桨的投影原理及其型值参数,建立螺旋桨的三维模型。运用计算流体动力学(Computational fluid dynamics,CFD)理论,采用分区混合网格方案,结合雷诺时均纳维斯托克斯(Reynolds-averagednavier-stokes,RANS)方程和三种不同的湍流模型对螺旋桨三维粘性流动进行数值模拟。所采用的网格划分方法具有网格数量少、质量高的特点。计算结果得到螺旋桨的推力系数、转矩系数以及尾流场的速度、压力分布等水动力特性参数,预报值与试验数据吻合较好,验证了数值方法的正确性,且说明雷诺应力模型(Reynolds stress model,RSM)这种湍流模型更适合螺旋桨粘性流场的数值计算,具有较高的预报精度,为复杂旋转机械粘性流场计算中湍流模式的选取提供参考意见。通过对螺旋桨敞水性能的分析,得到螺旋桨粘性流动所特有的流动分离、梢涡的形成与结构以及尾流场等一些重要现象和特征,为螺旋桨噪声、振动的研究和新型高效推进器的设计提供理论指导和技术支持。     

Turbulent convection in round tube equipped with propeller type swirl generators

This article is aimed at studying the heat transfer, friction loss and enhancement efficiency behaviors in a heat exchanger tube equipped with propeller type swirl generators at several pitch ratios (PR). The investigation is performed for the Reynolds number ranging from 4000 to 21,000 under a uniform heat flux condition. The experiments are also undertaken for several blade numbers of the propeller (N = 4, 6, and 8 blades) and for different blade angles (θ = 30°, 45°, and 60°). The influences of using the propeller rotating freely, on heat transfer enhancement, pressure loss, and enhancement efficiency, are reported. In the experiments, the swirl generator is used to create a decaying swirl in the tube flow. Average Nusselt numbers are determined and also compared with those obtained from other similar cases. The experimental results indicate that the tube with the propeller inserts provides considerable improvement of the heat transfer rate over the plain tube around 2.07 to 2.18 times for PR = 5, blade angles θ = 60° and N = 8. The use of the propeller leads to maximum enhancement efficiency up to 1.2. Thus, because of strong swirl or rotating flow, the propellers and their blade numbers become influential upon the heat transfer enhancement. The increase in friction factor from using the propeller is found to be 3–18 times over the plain tube. Correlations for Nusselt number (Nu) and friction factor (f) for the inserted tube are provided and the performance evaluation criterion to access the real benefits in using the swirl generators of the enhanced tube is also determined.     

基于Matlab的船用螺旋桨计算机实时仿真及GUI设计

基于船用螺旋桨仿真系统的应用实际,讨论了Matlab/Simulink计算机仿真软件在系统仿真中的应用;详细阐述了系统仿真模型的建立以及实时仿真的实现.针对该系统介绍了利用Matlab内嵌GUI设计工具,进行仿真系统图形用户界面GUI的设计和实现方法.在实际应用中证明了利用MATLAB所设计的计算机仿真系统,实现方便,性能可靠且操作灵活,有较好的实用性.