An experimental investigation conducted in order to determine bearing dynamic coefficients of two hydrodynamic bearings using impulse responses

• Autorzy: Breńkacz Ł. , Żywica G.
• Języki publikacji: EN

Abstrakty

EN

The paper presents the experimental investigation carried out in order to identify bearing dynamic coefficients of two hydrodynamic bearings from impulse responses. In this method the stiffness, damping and mass coefficients of two hydrodynamic bearings were calculated in a single algorithm. For each rotational speed, were obtained 12 dynamic coefficients which enable to fully describe the dynamic state of the rotor. Exciting force signals, applied using an impact hammer were shown. Displacements of the shaft were measured by eddy current sensors. The measurements were carried out at various rotational speeds, including resonance speeds. The vibration amplitude in a resonance case increases significantly with time after the excitation was induced by an impact hammer. Excitations of the rotor with an impact hammer were recorded using a high-speed camera. These unique recordings and simultaneous analysis of the trajectory of the bearing journals depict the contact phenomena that occur during impulse excitation of the rotor.

Słowa kluczowe

EN

hydrodynamic bearings; bearing dynamic coefficients; experimental study

• Wydawca: Wydawnictwo Instytutu Maszyn Przepływowych PAN
• Czasopismo: Transactions of the Institute of Fluid-Flow Machinery
• Rocznik: 2016
• Tom: nr 133
• Strony: 39--54
• Opis fizyczny: Bibliogr. 18 poz., rys.

Twórcy

autor

Breńkacz Ł.

• Department of Turbine Dynamics and Diagnostics, Institute of Fluid Flow Machinery, Polish Academy of Sciences, 80-231 Gdańsk, Fiszera 14, Poland

autor

Żywica G.

Bibliografia

• [1] Kiciński J. and Żywica G.: Steam Microturbines in Distributed Cogeneration. Springer, 2014.
• [2] Kiciński J.: The Dynamics of Rotors and Slide Bearings. IMP PAN, Maszyny Przepływowe, Gdańsk 2005 (in Polish).
• [3] Dimond T.W., Sheth P.N., Allaire P.E., He M.: Identification methods and test results for tilting pad and fixed geometry journal bearing dynamic coefficients – A review. Shock Vib. 16(2009), 1, 13–43.
• [4] Tiwari R., Lees A.W., Friswell M.I.: Identification of dynamic bearing parameters: a review. Shock Vibrat. Digest. 36(2004), 2, 99–124.
• [5] Delgado A.: Experimental identification of dynamic force coefficients for a 110 mm compliantly damped hybrid gas bearing. J. Eng. Gas Turb. Power 137(2015), 7, 072502-072502-8.
• [6] Zapomel J., Ferfecki P., and Kozánek J.: Application of the Monte Carlo method for investigation of dynamical parameters of rotors supported by magnetorheological squeeze film damping devices. Appl. Computat. Mech. 8(2014), 129–138.
• [7] Arora V., Van der Hoogt P.J.M., Aarts R.G.K.M., De Boer A.: Identification of stiffness and damping characteristics of axial air-foil bearings. Int. J. Mech. Mater Des. 7(2011), 3, 231–243.
• [8] Nordmann R., Schoellhorn K.: Identification of stiffness and damping coefficients of journal bearings by means of the impact method. In: Proc. 2nd Int. Conf. on Vibrations in Rotating Machinery, 1980, 231–238.
• [9] Qiu Z.L., Tieu A.K.: Identification of sixteen force coefficients of two journal bearings from impulse responses. Wear 212(1997), 2, 206–212.
• [10] Breńkacz Ł.: Identification of stiffness, damping and mass coefficients of rotor – bearing system using impulse response method. J. Vibroeng. 17(2015), 5, 2272–2282.
• [11] Breńkacz Ł.: Identification of bearing dynamic coefficients with consideration of shaft unbalance. Mechanik 7(2015) (in Polish).
• [12] Breńkacz Ł., Żywica G.: The sensitivity analysis of the method for identification of the bearing dynamic coefficients. Springer Proc. Dyn. Sys. – Modeling (2016) (accepted for printing)
• [13] Breńkacz Ł., Żywica G.: Numerical estimation of linear and nonlinear stiffness and damping coefficients of journal hydrodynamic bearings. Mechanik 7(2016), 648–649, (in Polish).
• [14] Breńkacz Ł.: Adequacy ranges of linear and nonlinear methods for determining the dynamic properties of the rotating machinery. Doctoral dissertation, Gdańsk 2016 (in Polish).
• [15] Rao K.R., Kim D.N., Hwang J.J.: Fast Fourier Transform – Algorithms and Applications. Dordrecht 2010.
• [16] Muszyńska A.: Rotordynamics. Taylor & Francis, LLC, Boca Raton 2005.
• [17] Manikandan S., Tiwari R., Dwivedy S.K.: Identification of rotor dynamic parameters of seals using impact hammer method. In: Proc. 12th Nat. Conf. on Machines and Mechanisms (NaCoMM-2005), IIT Guwahati, Dec. 16–17, 2005, 384–390.
• [18] Lal M., Tiwari R.: Multi-fault identification in simple rotor-bearing-coupling systems based on forced response measurements. Mech. Mach. Theory 51(2012), 87–109.