虑及多转速的核心机转子高速动平衡试验

为满足航空发动机整机动平衡对转子不平衡振动精稳抑制的需求,采用虑及多转速状态的转子高速动平衡优化配平方法,开展了核心机转子动平衡试验。以核心机转子系统为对象,研究在高压压气机转子第4、9级盘上配重抑制高压涡轮振动的可行性。综合考虑核心机转子在多转速下的振动状态,以残余振动平方和及残余振动最大值为目标函数,采用优化算法对配平方案进行优化,制定了核心机转子高速动平衡方案。在核心机转子系统试验台上分别进行了单平面-单转速、单平面-多转速、双平面-单转速以及双平面-多转速动平衡的试验。结果表明:采用虑及多转速状态的转子高速动平衡优化配平方法能使因不平衡引起的核心机转子振动在工作转速区间内均有所减小。

多转速抛光机创新设计及振动实验研究

为了提高瓷砖抛光机的效率,提出一种多转速抛光机。分析了多转速抛光机结构和原理,设计了磨头变速机构。以新多转速抛光机磨头为研究对象,建立磨头动力学模型。得出Z方向的振动大于X、Y方向的振动,并通过实验得到验证。通过实验确定了多转速抛光机粗磨磨头转速为570 r/min、压力为2.6～3.2 MPa,精磨磨头转速为475r/min、压力为2.6 MPa,抛光磨头转速为570 r/min、压力为3.2 MPa。

机器多转速的柔性作业车间绿色调度问题

为了减少制造过程中的能耗,从生产运作的角度探讨了如何在制造业生产调度中实现绿色制造。以柔性作业车间调度问题为背景,考虑了机器多转速,在不影响生产进度的前提下通过调节机器转速来实现绿色制造。首先建立了考虑机器多转速的柔性作业车间调度优化模型,构建了能耗计算模型;然后依据带精英策略的非支配排序遗传算法的框架,提出了综合考虑完工时间和能源消耗的低碳调度算法,设计了多种变异方式,提出了精英保留与末位淘汰的选择方式;最后的数值实验结果表明,所提算法能够很好地求解此类问题。

变转速工况下汽车冷却水泵内外特性变化规律

以某汽车冷却水泵为研究对象,通过定常流场模拟和试验得到多转速工况下的外特性曲线,二者有较好的一致性:扬程随转速均匀变大,高效区增宽并向大流量区偏移。通过非定常流场模拟获得了不同转速下流道内流线、径向速度和压力脉动等分布特性,并对比分析了蜗壳和叶轮所受轴向力和径向力的变化趋势。结果表明:流体速度值、压力脉动幅值以及受力等随转速有较大变化,说明该泵长期远离高效区运行,存在较大的运行稳定性隐患和节能优化空间。

集成工艺规划与车间调度的节能优化方法

为了在柔性作业车间制造过程中实现节能优化,从工艺规划与车间调度集成的角度,提出了集成工艺规划与车间调度的节能优化方法,以降低作业车间的能耗。首先,提出了车间能耗计算方法,构建了以总能耗和完工时间最小的优化目标模型。其次,提出了一种改进的灰狼优化算法,采用一种四层编码方式,设计了新的种群更新方法,并引入交叉算子,对调度模型进行求解。最后,通过作业车间实例验证了上述模型的节能潜力及改进算法的可行性。

某小型涡扇发动机转子高速动平衡试验

针对在高转速情况下如何降低转子的振动问题,对转子高速动平衡的原理及一般方法进行论述,对某小型涡扇发动机转子进行高速动平衡。试验结果表明,高速动平衡技术能有效的降低转子振动,采用多平面多转速影响系数法对该柔性转子的一、二阶高速动平衡是可行的,对保证同类型转子正常工作具有技术指导意义和工程应用价值。

基于加权遗传算法的旋转机械不平衡振动溯源定位方法研究

针对高端旋转机械多平面多转速下的不平衡振动定位问题,提出一种基于加权遗传算法的转子不平衡溯源定位方法,并开发了一套不平衡溯源计算软件。该方法在遗传算法的基础上进行改进,增加了针对各测点各转速下振动的赋权过程,并分别在某双跨转子有限元模型以及某模拟发电机实验台上,通过将该方法与最小二乘法和遗传算法进行对比,进一步验证该改进方法的不平衡量溯源效果。仿真结果表明,该技术针对高权重测点处的溯源精度高于其余两种算法。在模拟发电机转子实验台上,应用该技术开展多平面多转速不平衡溯源定位实验。实验结果表明,基于加权遗传算法的溯源结果进行平衡后,高权重测点振幅降幅超过80%,降幅较其余两种算法有明显提升。综合仿真与实验结果,该方法较最小二乘法与遗传算法更有针对性及目的性。

某小型涡扇发动机柔性转子高速动平衡试验研究

试验研究某小型涡扇发动机柔性转子系统不同环境下的动力学特性;针对柔性转子的特点,采用多平面多转速影响系数法对该转子系统进行一、二阶高速动平衡试验。试验发现,真空环境下和大气环境下的动力学特性幅频特性有差异,但相频特性基本相同。结果表明,采用多平面多转速影响系数法能够有效实施柔性转子系统的高速动平衡,并且效果显著。

液压泵空载排量测定方法的探讨

本文针对现有GD7936-87及GB/T 7936-2012空载排量测定方法中空载排量测试误差较大、不能反映液压泵在整个工作范围内的空载排量特性的问题加以分析,提出了一种新的空载排量测试方法:多转速零压力截取法,并进行了试验和比较分析。试验结果表明,该方法测得的空载排量值具有较高精度,能代表液压泵在整个工作范围内的空载排量特性,对相关从业人员进行空载排量测定具有较大的参考意义。

浅析一水柠檬酸结晶工艺和设备选型

分析一水柠檬酸的结晶过程及其影响因素,对其结晶工艺进行创新,优化选择结晶设备,并成功地工业化应用且取得了显著的经济效益。

压缩机用永磁无刷直流电机的多物理场分析

为了降低电动涡旋压缩机的电机电磁噪声,对于有外套的弧形磁片式转子电机在中低频电磁噪声较为明显的情况,提出采用内置V型径向式转子电机,并对样机进行了多物理场联合仿真和实验测试。通过仿真分析得到了内置V型径向式转子电机在1000~6000 r/min的6个转速下的多物理场的振动等效辐射声功率瀑布图以及噪声的远场声压级瀑布图,并在噪声室通过汽车空调压缩机噪声测试运转台测试了样机的振动及噪声,将仿真的数据与实验数据进行对比,验证了基于ANSYS Workbench平台永磁无刷直流电机在多转速下的耦合场分析的准确性。

悬浮载荷对无轴承永磁电机电磁力波及电磁噪声影响分析

无轴承永磁电机相比普通永磁同步电机增加了一套用于控制转子位置的悬浮绕组,产生悬浮磁场,使得气隙磁场发生畸变,改变电磁力,进而对电磁噪声产生影响。针对该问题,采用解析法推导归纳了无轴承电机电磁力波阶数和频率规律;针对交替极无轴承永磁电机,建立参数化有限元多物理场分析模型,进一步计算电磁力波的大小;通过仿真实验得出了悬浮电流大小和相位对电磁噪声的影响规律以及悬浮电流对多转速下电磁噪声的影响规律。

大型高压空气组装式压缩机的开发应用

大型高压空气组装式压缩机是一种多轴、多转速的透平式离心压缩机,多用于大型空分装置、空气储能领域。压缩机最大可满足10万空分装置、150MW储能规模需求,出口压力最高可达14Mpa,具有高速、重载的特点。相比于单轴、同转速的透平式离心压缩机,组装式压缩机具备占地面积小、成本低、便于安装维修等诸多优点。文中主要表述组装式压缩机的气动设计、结构特点分析、力学研究方向、多工况调节方法、优缺点分析。

Single-acting double-stator multi-pumps and multi-motors

We investigated a series of novel motors and pumps with a new structure called double-stator. Double-stator can be used as pump or motor just for the working condition on demand. A certain amount of pumps or motors are formed in one shell and these subpumps or submotors can work alone or in company without influence on other pumps or moters. This kind of double-stator pumps (motors) are called multi-pumps (multi-motors). Through the analysis of multifarious connection modes of single-acting double-stator multi-pumps and multi-motors, the mathematical expressions of output flow rate, rotational speed and torque are acquired. The results indicate that different flow rates can be provided by one fixed displacement double-stator multi-pump system under the condition of an unalterable driven speed. Likewise, under the terms of a fixed input flow and without complex variable mechanisms, the functions of double speeds, multiple speeds and even differential connection can be realized by a double-stator multi-motor system with various output rotational speeds and torques.

Influence of multipass high rotating speed friction stir processing on microstructure evolution,corrosion behavior and mechanical properties of stirred zone on AZ31 alloy

The influence of multipass high rotating speed friction stir processing(FSP)on the microstructure evolution,corrosion behavior,and tensile properties of the stirred zone(SZ)was investigated by EBSD,TEM,SEM,electrochemical workstation and electronic universal testing machine.The mean grain size of the SZ is significantly refined,and it increases with the increase of the processing pass.In addition to an obvious increase in the number,the distribution ofβ-Al12Mg17 precipitates also becomes more uniform and dispersed with increasing the processing pass.Compared with the as-received AZ31 alloy,the tensile properties of the SZ are hardly improved,but the corrosion resistances are significantly enhanced.The corrosion potential of the SZ prepared by 4-pass FSP is increased from−1.56 V for the unprocessed AZ31 alloy to−1.19 V,while the corrosion current is decreased from 1.55×10^−4 to 5.47×10^−5 A.

Development of a simple RPM measurement system

The design and development of a timer based revolution per minute(RPM)measurement system were described in this paper.The rotating shaft of a dc motor was used to measure the RPM and timer integrated circuit(IC)555 was used in astable mode.The frequency of timer output waveform measured by a digital storage oscilloscope(DSO)is almost linearly proportional to the RPM of rotating shaft,and the RPM also linearly varies with the change of the external input voltage level.Hence the linear relationship between the frequency of timer output waveform and the RPM can be obtained.The main advantages of this developed system are linear input-output relationship,small size,easy to carry and cost effective.

基于多重优化的多级盘转子虚拟装配平衡方法

针对航空发动机转子振动精准抑制对装配工艺的需求,提出了一种虑及多转速多级盘结构转子虚拟装配平衡优化方法。以多级盘转子试验台为对象建立了转子动力学模型,在各级盘残余不平衡量及转子原始振动已知的情况下,通过仿真模型进行虚拟装配。以转子各测点的残余振动以及转子整体不平衡力和不平衡力矩为优化目标,采用多重优化算法寻找各级轮盘装配角度的优化方案。最后在3盘转子系统试验台上进行了试验验证,结果表明,使用该方法可使转子在宽转速范围内振动均有所下降,其中最大下降幅度为85.75%。本文结果可为航空发动机多级盘结构转子装配提供方法和技术支撑。

A Robust Interacting Multisensor State Fusion Based on Adaptive Outlier Controlling Multirate Model

An adaptive outlier controlling multirate model based on Hong’s multirate kinetic model was represented in order to resist the outliers and utilize their useful information. Wavelet transform was introduced to detect and control the outliers. The multirate information extraction and the controlling of outliers were properly integrated to establish an adaptive outlier controlling multirate model. The proposed model was applied to multisensor state fusion with interacting multiple model (IMM), and a robust interacting multisensor state fusion algorithm was established based on adaptive outlier controlling multirate model. The Monte-Carlo simulation shows that it could improve the accuracy of fusion estimation by 70% compared to Hong’s algorithm and at least 14% to Xiao’s algorithm.

Nanoparticle distribution in a rotating curved pipe considering coagulation and dispersion

We study the evolution of the particle number concentration, mass concentration, particle polydispersity, particle diameter and geometric standard deviation considering particle coagulation and dispersion in a rotating curved pipe at different Reynolds number, Schmidt number and F number. It is found that, when the Coriolis force and the centrifugal force point to the same direction, particles concentrate near the outside edge of the pipe, which becomes more obvious as time goes by. The particle number and mass concentration increase faster at the early stage than that at the later stage, and approach a stable value finally. As the coagulation proceeds, the particle diameter, polydispersity and geometric standard deviation increase and have high values in the region close to the outside edge of the pipe. When the Coriolis force and the centrifugal force point to the oppo- site direction and the Coriolis force is more dominant than the centrifugal force, particles concentrate near the inside edge of the pipe. The particles in the region with a high number concentration have high mass concentration, large diameter and high polydispersity as well as large geometric standard deviation. The particle distribution is dependent on the balance of the pipe curvature and rotating speed. The Reynolds number and the Schmidt number have effects on the particle distribution when other parameters remain unchanged. An increase in the Reynolds number leads to an increase in particle number concentration and mass concentration, and a decrease in particle polydispersity, particle diameter and geometric standard deviation. With the increase of Schmidt number the particle number concentration and mass concentration increase, and the particle polydispersity, particle diameter and geometric standard deviation decrease.

Effect of Catch Cup Geometry on 3D Boundary Layer Flow over the Wafer Surface in a Spin Coating

Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor instruments become more sophisticated. Spin coating is usually used for spreading photoresist on a wafer surface. However, since rotating speed of the disk is very high in spin coating, the dropped photoresist scarers outward and reattaches on the film surface. A catch cup is set up outside the wafer in spin coating, and scattered photoresist mist is removed from the wafer edge by the exhaust flow generated at the gap between the wafer edge and the catch cup. In the dry process of a spin coating, it is a serious concern that the film thickness increases near the wafer edge in the case of low rotating speed. The purpose of this study is to make clear the effect of the catch cup geometry on the 3D boundary layer flow over the wafer surface and the drying rate of liquid film.