بررسی و تشخیص پدیده OIL WHIRL وابسته به بار در توربوژنراتور ۵ مگاواتی با استفاده از تحلیل FFT وORBIT

The fluid film instability phenomenon (Oil Whirl) is a significant instability in journal bearings of turbomachinery, causing a considerable increase in vibrations and the risk of mechanical damage. This study presents a comprehensive analysis of the vibration behavior of a 5 MW turbogenerator, which is of particular importance due to the rarity of Oil Whirl occurrence in similar bearings. Vibration measurements were conducted under various operating conditions and analyzed using Fast Fourier Transform (FFT) spectral analysis and orbit plots to identify the frequency characteristics and dynamic features of the phenomenon. The results indicate that Oil Whirl occurs within specific ranges of rotational speed and load, leading to an ampli-fication of the bearing vibration amplitudes. The precise agreement between the rotor motion under fault conditions, as shown in the orbit plots, and well-established theoretical models validates the applied analysis methods. This analytical approach can serve as an effective tool in condition monitoring systems and early instability detection, assisting operators and vibra-tion engineers in accurately and rapidly identifying similar faults in comparable equipment. Therefore, employing these methods can play a crucial role in enhancing the reliability and performance of turbomachines.