Numerical investigations on axial and radial blade rubs in turbo-machinery

International Conference on Materials Technology and Energy

Abdelrhman, Ahmed M.^1 ; Sung Tang, Eric Sang^1 ; Leong, M. Salman^2 ; Al-Qrimli, Haidar F.^3 ; Rajamohan, G.^1

Curtin University Malaysia, CDT 250, Sarawak, Miri

98009, Malaysia^1

Institute of Noise and Vibration, University Technology Malaysia, Malaysia^2

Heriot-Watt University, Putrajaya

62200, Malaysia^3

关键词: Aerodynamic efficiency;    Blade passing frequency;    Comparison study;    Engineering fields;    Multiple frequency;    Non-linear vibrations;    Numerical investigations;    Rubbing condition;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/217/1/012015/pdf
DOI  :  10.1088/1757-899X/217/1/012015

来源: IOP

【 摘 要 】

In the recent years, the clearance between the rotor blades and stator/casing had been getting smaller and smaller prior improving the aerodynamic efficiency of the turbomachines as demand in the engineering field. Due to the clearance reduction between the blade tip and the rotor casing and between rotor blades and stator blades, axial and radial blade rubbing could be occurred, especially at high speed resulting into complex nonlinear vibrations. The primary aim of this study is to address the blade axial rubbing phenomenon using numerical analysis of rotor system. A comparison between rubbing caused impacts of axial and radial blade rubbing and rubbing forces are also aims of this study. Tow rotor models (rotor-stator and rotor casing models) has been designed and sketched using SOILDSWORKS software. ANSYS software has been used for the simulation and the numerical analysis. The rubbing conditions were simulated at speed range of 1000rpm, 1500rpm and 2000rpm. Analysis results for axial blade rubbing showed the appearance of blade passing frequency and its multiple frequencies (lx, 2x 3x etc.) and these frequencies will more excited with increasing the rotational speed. Also, it has been observed that when the rotating speed increased, the rubbing force and the harmonics frequencies in x, y and z-direction become higher and severe. The comparison study showed that axial blade rub is more dangerous and would generate a higher vibration impacts and higher blade rubbing force than radial blade rub.