带有减振装置的转子采掘机振动

应用统计学和动力学的几个拓扑理论和有关矩阵方法，对带有减振器的重型机械－采掘机的振动问题进行了研究。参考2PT－400－17／1.3型机器的动力模型，分析了该系统的自由振动特性，给出了详细的分析过程和结果；在此基础上，深入分析了系统在强迫振动下的幅度－频率特性，并给出了详细的分析过程和结果。     

磁轴承柔性转子系统动力特性建模与优化仿真

建立了电磁轴承柔性有质转子系统计入陀螺、阻尼、轴－径向动力耦合及机械－电磁－控制系统耦合等影响的动力特性分析计算数学模型，导出了多变量控制系统的标准化系统矩阵向量方程。以系统仿真响应为目标，通过复合寻优方法实现了系统最佳工作区（点）的求解。对优化仿真结果与试验现场调试结果进行了对比分析。     

Dynamic balancing of dual-rotor system with very little rotating speed difference

Unbalanced vibration in dual-rotor rotating machinery was studied with numerical simulations and experiments. A new method is proposed to separate vibration signals of inner and outer rotors for a system with very little difference in rotating speeds. Magnitudes and phase values of unbalance defects can be obtained directly by sampling the vibration signal synchronized with reference signal. The balancing process is completed by the reciprocity influence coefficients of inner and outer rotors method. Results showed the advantage of such method for a dual-rotor system as compared with conventional balancing.     

利用改进的精细积分法求解转子系统的瞬态响应

针对用精细积分法求解转子系统的瞬态响应时会出现奇异矩阵的情况,对精细积分法进行改进。利用改进的精细积分法对Jeffcott转子模型系统的瞬态响应进行分析。算例与仿真实验论证了改进方法求解转子瞬态响应的可行性。     

K型偏心支撑钢框架支撑的设计研究

为研究不同支撑刚度K型偏心支撑钢框架的抗震性能,对5个具有不同支撑截面的试件进行了非线性有限元分析。结果表明:为保证耗能梁段先行剪切屈服而支撑不屈曲,支撑应具有足够的刚度;支撑长细比较小的试件滞回性能较好,而长细比过小则会降低结构的延性和耗能性能;对于长细比较小的支撑,其翼缘宽厚比应严一些,而腹板高厚比则可适当放宽;支撑斜杆与横梁的连接焊缝发生断裂破坏的可能性较大,在施工中应对该处焊缝的焊接质量进行严格控制。并根据有限元模拟结果提出了设计和施工建议。     

Nusselt数在弯管对流换热中的作用

在工程应用中,管内Nu是一个非常重要的物理量,它反映了管内流体与外界的热交换特性。Nu可以分为周向Nup和平均Nu,周向Nup反映了壁面每个点上对流换热的强弱程度,而平均Nu反映的是管道整体的对流换热特性。数值研究表明:Gr数,Pr数以及Dn数较小的情况下,环形同心圆管道的换热效率最高,而当以上三个参数较大时,负偏心距时的换热效率最高。不管参数如何变化,正偏心距情况下的换热效率都最低。     

多支承转子-轴承系统试验台动力学设计

为实现多支承轴承-转子系统振动监测和机械设备故障诊断,设计研制了一台模拟大型旋转机械动力特性的多支承轴承-转子试验台。采用有限元算法,经过系统动力学设计计算和理论分析,表明本试验台具有良好的动力学特性和足够的稳定性裕度,能够进行多种转子动力学实验研究,具备机组机械振动监测、故障模拟、轴承负荷在线监测等多项功能。     

同步电机转子绕组接地监测灵敏度的仿真研究

对电阻平衡电桥接地监测的原理进行了详尽地论述,利用Matlab 6.5/Simulink 5.0的强大功能,对其进行灵敏度仿真分析,仿真结果与理论分析相吻合.     

Study on seal improvement and rotor thrust control of centrifugal compressor

Fluid pressure variations due to process fluctuations or balance drum seal degradation can result in rotor thrust increasing that may jeopardize thrust bearing and compressor’s reliability. Also, the leakage flow through balance drum seal can seriously affect the efficiency of compressor. A method that can improve both the efficiency and reliability of centrifugal compressor is presented. The method focused on rotor thrust control and balance drum seal upgrading. The low leakage feature of Dry-Gas-Seal（DGS）, high reliability of labyrinth, and the feasibility of upgrading existing structure are taken into account at the same time to design a combined labyrinth-dry gas seal system on the balancing drum. Based on the combined seal system, a Fault Self-Recovering（FSR） system for the fault of rotor shaft displacement is introduced to assure the safety and reliability of centrifugal compressor. The modern Computational Fluid Dynamics（CFD） is used to validate this envision. The numerical result and relevant information indicate that the combined sealing system could improve the efficiency of the centrifugal compressor by about 4%.