Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBC) system have overlooked the elastic deformation of the b...Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBC) system have overlooked the elastic deformation of the blade, while some only consider the whirl of the rotor, neglecting its spin. To address these limitations, this paper proposes a dynamic model with large rotation for the SDBC system. The model incorporates the spin and whirl of the rotor, enabling the realistic reproduction of multiblade rubbing faults. To verify the accuracy of the SDBC model with large rotation and demonstrate its capability to effectively consider the rotational effects such as the centrifugal stiffening and gyroscopic effects, the natural characteristics and dynamic responses of the proposed model are compared with those obtained from reported research and experimental results. Furthermore, the effects of the rotating speed, contact stiffness,and blade number on the dynamic characteristics of the SDBC system with multi-blade rubbing are investigated. The results indicate that the phase angle between the rotor deflection and the unbalance excitation force increases with the increasing rotating speed,which significantly influences the rubbing penetration of each blade. The natural frequency of the SDBC system with rubbing constrain can be observed in the acceleration response of the casing and the torsional response of the shaft, and the frequency is related to the contact stiffness. Moreover, the vibration amplitude increases significantly with the product of the blade number under rubbing, and the rotating frequency approaches the natural frequency of the SDBC system. The proposed model can provide valuable insight for the fault diagnosis of rubbing in bladed rotating machinery.展开更多
首先基于分离变量算法(method of separation of variables, MSV)求解了单节流孔静压气体轴承的层流边界层方程,研究了节流孔附近流场特性,阐明了节流孔出口附近压降现象是由于惯性效应导致,并研究了轴承几何参数和供气参数对压降现象...首先基于分离变量算法(method of separation of variables, MSV)求解了单节流孔静压气体轴承的层流边界层方程,研究了节流孔附近流场特性,阐明了节流孔出口附近压降现象是由于惯性效应导致,并研究了轴承几何参数和供气参数对压降现象的影响规律。最终提出了压降现象产生的临界条件为压比为0.940 9,也即压比大于临界压比时,压降现象消失。其次基于质量流量相等原则,结合层流边界层的MSV方法及雷诺方程的解析算法,提出了一种计算节流孔系数的新方法,并研究了轴承的几何参数及供气参数对节流孔系数的影响规律。结果显示,节流孔系数存在着参数敏感和不敏感区域,这是由于当压比小于等于0.6左右时,节流孔系数趋近于一个常数0.86左右。展开更多
基金Project(11972112)supported by the National Natural Science Foundation of ChinaProject(N2103024)supported by the Fundamental Research Funds for the Central Universities,China。
基金Project supported by the National Science and Technology Major Project of China (No. 2017-V-0009)the National Natural Science Foundation of China (Nos. 12032015 and 12121002)the National Funding Program for Postdoctoral Researchers of China (No. GZC20231586)。
文摘Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBC) system have overlooked the elastic deformation of the blade, while some only consider the whirl of the rotor, neglecting its spin. To address these limitations, this paper proposes a dynamic model with large rotation for the SDBC system. The model incorporates the spin and whirl of the rotor, enabling the realistic reproduction of multiblade rubbing faults. To verify the accuracy of the SDBC model with large rotation and demonstrate its capability to effectively consider the rotational effects such as the centrifugal stiffening and gyroscopic effects, the natural characteristics and dynamic responses of the proposed model are compared with those obtained from reported research and experimental results. Furthermore, the effects of the rotating speed, contact stiffness,and blade number on the dynamic characteristics of the SDBC system with multi-blade rubbing are investigated. The results indicate that the phase angle between the rotor deflection and the unbalance excitation force increases with the increasing rotating speed,which significantly influences the rubbing penetration of each blade. The natural frequency of the SDBC system with rubbing constrain can be observed in the acceleration response of the casing and the torsional response of the shaft, and the frequency is related to the contact stiffness. Moreover, the vibration amplitude increases significantly with the product of the blade number under rubbing, and the rotating frequency approaches the natural frequency of the SDBC system. The proposed model can provide valuable insight for the fault diagnosis of rubbing in bladed rotating machinery.
文摘首先基于分离变量算法(method of separation of variables, MSV)求解了单节流孔静压气体轴承的层流边界层方程,研究了节流孔附近流场特性,阐明了节流孔出口附近压降现象是由于惯性效应导致,并研究了轴承几何参数和供气参数对压降现象的影响规律。最终提出了压降现象产生的临界条件为压比为0.940 9,也即压比大于临界压比时,压降现象消失。其次基于质量流量相等原则,结合层流边界层的MSV方法及雷诺方程的解析算法,提出了一种计算节流孔系数的新方法,并研究了轴承的几何参数及供气参数对节流孔系数的影响规律。结果显示,节流孔系数存在着参数敏感和不敏感区域,这是由于当压比小于等于0.6左右时,节流孔系数趋近于一个常数0.86左右。
