Jeong, Sena Jeon, Doyoung Lee, Yong Bok 2024-01-20T01:32:59Z 2024-01-20T01:32:59Z 2021-09-01 2017-05 0742-4795 https://pubs.kist.re.kr/handle/201004/122784 In this study, experimental and analytical analyses of the vibration stability of a 225 kW class turbo blower with a hybrid foil-magnetic bearing (HFMB) were performed. First, critical speed and unbalance vibration responses were examined as part of the rotordy-namic research. Its shaft diameter was 71.5 mm, its total length was 693 mm, and the weight of the rotor was 17.8 kg. The air foil bearing (AFB) utilized was 50 mm long and had a 0.7 aspect ratio. In the experiments conducted, excessive vibration and rotor motion instability occurred in the range 12,000-15,000 rpm, which resulted from insufficient dynamic pressure caused by the length of the foil bearing being too short. Consequently, as the rotor speed increased, excessive rotor motion attributable to aerodynamic and bearing instability became evident. This study therefore focused on improving rotor-dynamic performance by rectifying rigid mode unstable vibration at low speed, 20,000 rpm, and asynchronous vibration due to aerodynamic instability by using HFMB with vibration control. The experimental results obtained were compared for each bearing type (AFB and HFMB) to improve the performance of the vibration in the low-speed region. The experimental results show that the HFMB technology results in superior vibration stability for unbalance vibration and aerodynamic instability in the range 12,000-15,000 rpm (200-250 Hz). The remarkable vibration reduction achieved from vibration control of the HFMB-rotor system shows that oil-free turbomachinery can achieve excellent performance. English ASME PERFORMANCE COMPRESSOR Rigid Mode Vibration Control and Dynamic Behavior of Hybrid Foil-Magnetic Bearing Turbo Blower Article 10.1115/1.4034920 1 JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME, v.139, no.5 JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME 139 5 scie scopus 000398435700013 2-s2.0-85042638976 Engineering, Mechanical Engineering Article PERFORMANCE COMPRESSOR Turbo Blower Rigid Mode Vibration Control Foil bearing Magnetic bearing Dynamic behavior