Transient simulation of a squeeze film damped turbocharger rotor under consideration of fluid inertia and cavitation

• Autorzy: Drapatow Thomas , Alber Oliver , Woschke Elmar

Identyfikatory

DOI

10.24425/bpasts.2021.139201

• Języki publikacji: EN

Abstrakty

EN

Squeeze film dampers (SFDs) are commonly used in turbomachinery in order to introduce external damping, thereby reducing rotor vibrations and acoustic emissions. Since SFDs are of similar geometry as hydrodynamic bearings, the REYNOLDS equation of lubrication can be utilised to predict their dynamic behaviour. However, under certain operating conditions, SFDs can experience significant fluid inertia effects, which are neglected in the usual REYNOLDS analysis. An algorithm for the prediction of these effects on the pressure build up inside a finite-length SFD is therefore presented. For this purpose, the REYNOLDS equation is extended with a first-order perturbation in the fluid velocities to account for the local and convective inertia terms of the NAVIER-STOKES equations. Cavitation is taken into account by means of a mass conserving two-phase model. The resulting equation is then discretized using the finite volume method and solved with an LU factorization. The developed algorithm is capable of calculating the pressure field, and thereby the damping force, inside an SFD for arbitrary operating points in a time-efficient manner. It is therefore suited for integration into transient simulations of turbo machinery without the need for bearing force coefficient maps, which are usually restricted to circular centralized orbits. The capabilities of the method are demonstrated on a transient run-up simulation of a turbocharger rotor with two semi-floating bearings. It can be shown that the consideration of fluid inertia effects introduces a significant shift of the pressure field inside the SFDs, and therefore the resulting damper force vector, at high oil temperatures and high rotational speeds. The effect of fluid inertia on the kinematic behaviour of the whole system on the other hand is rather limited for the examined rotor.

Słowa kluczowe

EN

rotor dynamics; journal bearings; squeeze film damper; fluid inertia

PL

dynamika wirnika; łożysko ślizgowe; bezwładność cieczy

• Wydawca: Polska Akademia Nauk, Wydział IV Nauk Technicznych
• Czasopismo: Bulletin of the Polish Academy of Sciences. Technical Sciences
• Rocznik: 2021
• Tom: Vol. 69, nr 6
• Strony: art. no. e139201
• Opis fizyczny: Bibliogr. 18 poz., il., wykr., tab.

Twórcy

autor

Drapatow Thomas

• Institute of Mechanics, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany

autor

Alber Oliver

• MAN Energy Solutions SE, 86153 Augsburg, Germany

autor

Woschke Elmar

• Institute of Mechanics, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany

Bibliografia

• [1] M.B. Banerjee, R. Shandil, S. Katyal, G. Dube, T. Pal, and K. Banerjee, “A nonlinear theory of hydrodynamic lubrication,” J. Math. Anal. Appl., vol. 117, no. 1, pp. 48–56, 1986.
• [2] S. Hamzehlouia and K. Behdinan, “Squeeze film dampers supporting high-speed rotors: Fluid inertia effects,” Proc. Inst. Mech. Eng., Part J: J. Eng. Tribol., vol. 234, no. 1, pp. 18–32, 2020.
• [3] M. Ramli, J. Ellis, and J. Roberts, “On the computation of inertial coefficients in squeeze-film bearings,” Proc. Inst. Mech. Eng., Part C: J. Mech. Eng. Sci., vol. 201, no. 2, pp. 125–131, 1987, doi: 10.1243/PIME_PROC_1987_201_095_02.
• [4] E. Reinhardt and J. Lund, “Influence of fluid inertia on the dynamic properties of journal bearings.” J. Lubr. Technol., vol. 97 Ser F, no. 2, pp. 159–167, 1975.
• [5] A.Z. Szeri, A.A. Raimondi, and A. Giron-Duarte, “Linear Force Coefficients for Squeeze-Film Dampers,” J. Lubr. Technol., vol. 105, no. 3, pp. 326–334, 07 1983.
• [6] A.Z. Szeri, Fluid Film Lubrication: Theory and Design. Cambridge University Press, 1998.
• [7] Z. Guo, T. Hirano, and R.G. Kirk, “Application of CFD analysis for rotating machinery: Part 1 — hydrodynamic, hydrostatic bearings and squeeze film damper,” in Volume 4: Turbo Expo 2003. ASME, 2003, doi: 10.1115/gt2003-38931.
• [8] C. Xing, M.J. Braun, and H. Li, “A three-dimensional navierstokes-based numerical model for squeeze film dampers. Part 2—effects of gaseous cavitation on the behavior of the squeeze film damper,” Tribol. Trans., vol. 52, no. 5, pp. 695–705, Sep 2009, doi: 10.1080/10402000902913311.
• [9] V. Constantinescu, Laminar Viscous Flow. Berlin Heidelberg: Springer Science & Business Media, 2012.
• [10] J. Gehannin, M. Arghir, and O. Bonneau, “Complete squeezefilm damper analysis based on the “bulk flow” equations,” Tribol. Trans., vol. 53, no. 1, pp. 84–96, 2009, doi: 10.1080/10402000903226382.
• [11] S. Lang and S. Verlag, Effiziente Berechnung von Gleitlagern und Dichtspalten in Turbomaschinen, ser. Forschungsberichte zur Fluidsystemtechnik. Shaker Verlag, 2018.
• [12] H. Peeken and J. Benner, “Beeinträchtigung des Druckaufbaus in Gleitlagern durch Schmierstoffverschäumung,” in Gleit- und Wälzlagerungen: Gestaltung, Berechnung, Einsatz; Tagung Neu-Ulm, 14. und 15. März 1985 / VDI-Ges. Entwicklung, Konstruktion, Vertrieb. – (VDI-Berichte; 549), 2013, pp. 373–397.
• [13] Ü. Mermertas, “Nichtlinearer Einfluss von Radialgleitlagern auf die Dynamik schnelllaufender Rotoren, Dissertation,” Düren, Aachen, 2003.
• [14] E. Woschke, C. Daniel, and S. Nitzschke, “Excitation mechanisms of non-linear rotor systems with floating ring bearings – simulation and validation,” Int. J. Mech. Sci., vol. 134, pp. 15‒27, 2017, doi: 10.1016/j.ijmecsci.2017.09.038.
• [15] R. Eymard, G. Thierry, and R. Herbin, “Handbook of numerical analysis,” vol. 7, pp. 731–1018, 01 2000.
• [16] V.V. Moca, A. Nagy-Dăbâcan, H. Bârzan, and R. C. Mure¸san, “Superlets: time-frequency super-resolution using wavelet sets,” bioRxiv, 2019.
• [17] S. Hamzehlouia and K. Behdinan, “A study of lubricant inertia effects for squeeze film dampers incorporated into highspeed turbomachinery,” Lubricants, vol. 5, p. 43, 10 2017, doi: 10.3390/lubricants5040043.
• [18] L. San Andrés and J. Vance, “Effects of fluid inertia and turbulence on the force coefficients for squeeze film dampers,” J. Eng. Gas Turbines Power, vol. 108, 04 1986, doi: 10.1115/1.3239908.

Uwagi

Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2021).