• Title/Summary/Keyword: 회전체역학

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Rotordynamic Analysis of Automotive Turbochargers Supported on Ball Bearings and Squeeze Film Dampers in Series: Effect of Squeeze Film Damper Design Parameters and Rotor Imbalances (볼 베어링과 스퀴즈 필름 댐퍼로 지지되는 차량용 터보차저의 회전체동역학 해석: 스퀴즈 필름 댐퍼 설계 인자와 회전체 불균형 질량의 영향)

  • Kim, Kyuman;Ryu, Keun
    • Tribology and Lubricants
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    • v.34 no.1
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    • pp.9-15
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    • 2018

  • Modern high-performance automotive turbochargers (TCs) implement ceramic hybrid angular contact ball bearings in series with squeeze film dampers (SFDs) to enhance transient responses, thereby reducing the overall emission levels. The current study predicts the rotordynamic responses of the commercial automotive TCs (compressor wheel diameter = ~53 mm, turbine wheel diameter = ~43 mm, and shaft diameter at the bearing locations = ~7 mm) supported on ball bearings and SFDs for various design parameters of SFDs, including radial clearance, axial length, lubricant viscosity, and rotor imbalance conditions (i.e., amplitudes and phase angles) while increasing rotor speed up to 150 krpm. This study validates the predictive rotor finite element model against measurements of mass, polar and transverse moments of inertia, and free-free mode natural frequencies and mode shapes. A nonlinear rotordynamic model integrates nonlinear force coefficients of SFDs to calculate the transient responses of the TC rotor-bearing system. The predicted results show that SFD radial clearances, as well as phase angles of rotor imbalances, have the paramount effect on the dynamic responses of TC shaft motions.

  • https://doi.org/10.9725/kts.2018.34.1.9 인용 PDF KSCI

Critical Speed Analysis of a 7 Ton Class Liquid Rocket Engine Turbopump (7톤급 액체로켓엔진 터보펌프 임계속도 해석)

  • Jeon, Seong-Min;Kim, Jin-Han
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.11-15
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    • 2012

  • A rotordynamic analysis is performed for a 7 ton class turbopump applied to the third stage LRE(Liquid Rocket Engine) of the KSLV(Korea Space Launch Vehicle). Based on the heritage of the developed experimental 30 ton class turbopump and developing 75 ton class turbopump for the KSLV first and second stage LRE, the 7 ton class turbopump is designed as an one-axis rotor turbopump. Two rotor systems comprised of one oxidizer pump assembly and the other fuel pump-turbine assembly are connected each other using a spline shaft and operating at a design speed. Through the rotordynamic analysis, it is investigated that the turbopump acquires sufficient separate margin of critical speed as a sub-critical rotor.

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