DYNAMIC BEARING CHARACTERISTICS OF ELASTIC RING SQUEEZE FILM DAMPER: PRESSURE DISTRIBUTION, RING DEFORMATION AND CONTACTS

2015 ◽  
pp. 13-14
Author(s):  
Qian DING
Keyword(s):  
Pressure Distribution ◽  
Squeeze Film ◽  
Elastic Ring ◽  
Squeeze Film Damper ◽  
Ring Deformation

Sealing Effect on the Performance of Squeeze Film Damper

2009 ◽  
Author(s):  
Changhu Xing ◽  
Minel J. Braun ◽  
Hongmin Li
Keyword(s):  
Pressure Distribution ◽  
Finite Volume ◽  
Piston Ring ◽  
Hydrodynamic Forces ◽  
Squeeze Film ◽  
Squeeze Film Damper ◽  
Damping Coefficients ◽  
End Plate ◽  
Inertia Coefficient ◽  
Ring Seal

Seals used in the squeeze film damper restrict the side leakage of the lubricant, thus providing a measure of additional damping. In this paper, the serrated piston ring and end-plate seals are studied numerically using CFD-ACE+, a commercially available finite volume based algorithm. Research shows that the damping coefficients for the piston ring seal decrease in magnitude with the increase in the number of axial grooves in the circumferential direction until they reach a fairly constant value. However, the pressure distribution and hence the hydrodynamic forces are strongly affected by the number and geometry of the axial grooves. The damping coefficients for the end plate seal increase in magnitude rapidly with the decrease of the seal clearance below the clearance of the damper, but increase slowly when the seal clearance is larger than that of the damper. The direct inertia coefficient increases with the decrease in the seal clearance but the magnitude of cross-coupled inertia coefficients increases with the decrease in the seal clearance, and then falls down towards the values for the infinitely long bearing assumption. Both the damping and inertia coefficients increase with the increase in seal length.

Dynamic characteristics of elastic ring squeeze film damper

2019 ◽  
Vol 71 (10) ◽  
pp. 1144-1151
Author(s):  
Zhenlin Wang ◽  
Zhansheng Liu ◽  
Guanghui Zhang
Keyword(s):  
Reynolds Equation ◽  
High Order ◽  
Squeeze Film ◽  
Radial Deformation ◽  
Elastic Ring ◽  
Content Type ◽  
Squeeze Film Damper ◽  
Force Coefficients ◽  
Pressure Profiles ◽  
Frequency Components

Purpose The purpose of this paper is to present a numerical model to investigate the dynamic behavior and force coefficients of a compact squeeze film damper with dual film clearances adjusted by an elastic ring, known as elastic ring squeeze film damper (ERSFD). Design/methodology/approach The governing equations of ERSFD as well as the boundary conditions are obtained based on Reynolds equation. A simplified Greenwood–Williamson model is implemented to investigate the contact behavior between the elastic ring and the journal. The interactions between the films and the elastic ring are achieved by block iterative method. Findings The radial deformation as well as velocity of the elastic ring are captured to illustrate the pressure profiles of the inner and outer films. High-order frequency components related to the number of the boss N are observed on the frequency spectrum of the film force. The force coefficients of the ERSFD are constant for a wider range of non-dimensional whirling radius ε compared with conventional squeeze film damper. Originality/value The force coefficients of the ERSFD are obtained by assuming that the journal center moves in a circular centered orbit. High-order frequency components related to the number of bosses N are observed. These findings may provide helpful materials for the application of the ERSFD.

Study on the Ultrahigh Speed Grinding of Superhard Materials with Squeeze Film Damping Technology

2010 ◽  
Vol 638-642 ◽  
pp. 2369-2374
Author(s):  
Tian Biao Yu ◽  
Hu Li ◽  
Jian Yu Yang ◽  
Wan Shan Wang
Keyword(s):  
Pressure Distribution ◽  
Experimental Result ◽  
Squeeze Film ◽  
Grinding Wheel ◽  
Superhard Materials ◽  
Squeeze Film Damper ◽  
Machining Quality ◽  
Squeeze Film Damping ◽  
Theory Research

In order to further improve machining quality of superhard materials, it was presented that adds a squeeze film damper on the wheel spindle of ultrahigh speed grinder as a assistant elastic sustain to attenuate the vibration of the wheel spindle. Work principle of squeeze film damper was analyzed; the squeeze film pressure distribution was researched through simulation and damper parameters effect on damping coefficient was studied. Base on the theory research the damper was designed and experiments was done. Experimental result shows the amplitude of the grinding wheel spindle can be reduced 20% and machining quality of superhard materials can be improved 10%～20%. Research works provides a new method for superhard materials machining.

Squeeze film dampers supporting high-speed rotors: Fluid inertia effects

2019 ◽  
Vol 234 (1) ◽  
pp. 18-32 ◽  
Author(s):  
Sina Hamzehlouia ◽  
Kamran Behdinan
Keyword(s):  
Thin Film ◽  
Pressure Distribution ◽  
Closed Form ◽  
Hydrodynamic Pressure ◽  
Fluid Film ◽  
Squeeze Film ◽  
Squeeze Film Damper ◽  
Thin Film Equations ◽  
Squeeze Film Dampers ◽  
Reaction Forces

This work represents closed-form analytical expressions for the operating parameters for short-length open-ended squeeze film dampers, including the lubricant velocity profiles, hydrodynamic pressure distribution, and lubricant reaction forces. The proposed closed-form expressions provide an accelerated calculation of the squeeze film damper parameters, specifically for rotordynamics applications. In order to determine the analytical solutions for the squeeze film damper parameters, the thin film equations for lubricant are introduced in the presence of the influence of lubricant inertia. Subsequently, two different analytical techniques, namely the momentum approximation method, and the perturbation method are applied to the thin film equations. Moreover, the solution for the lubricant flow equations are analytically determined to represent closed-form expressions for the hydrodynamic pressure distribution and the velocity component profiles in squeeze film dampers. Additionally, the expressions for the hydrodynamic pressure distribution are integrated over the journal surface, either numerically or analytically by using Booker’s integrals, to develop expressions for the fluid film reaction forces. Lastly, the developed squeeze film damper models are incorporated into simulation models in Matlab and Simulink®, and the results are compared against a well-established force coefficient model to verify the accuracy of the calculations. The results of the simulations verify the effect of the lubricant inertia components, namely the convective and temporal (i.e., unsteady) inertia components on the squeeze film damper dynamics, including hydrodynamic pressure distribution and fluid film reaction forces. Additionally, the simulation results suggest a close agreement between the proposed models and the results in the literature.

scholarly journals Numerical and Experimental Investigation of the Effect of Cavitation on Dual Clearance Squeeze Film Damper

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Zhaojun Feng ◽  
Guihuo Luo ◽  
Hai Yang ◽  
Wangqun Deng ◽  
Wei Chen ◽  
...  
Keyword(s):  
Numerical Model ◽  
Pressure Distribution ◽  
Negative Pressure ◽  
Experimental Results ◽  
Squeeze Film ◽  
Positive Pressure ◽  
Kinetic Properties ◽  
Squeeze Film Damper ◽  
Cavitation Effect ◽  
Pressure Zone

A new dynamic model is developed for the dual clearance squeeze film damper (DCSFD) considering the effect of cavitation in this paper. The relationship between the eccentricities of the inner and outer films is achieved based on the equations of motion. The Reynolds equation and Rayleigh–Plesset equation are employed to describe the kinetic properties of DCSFD and the cavitation effect of film, respectively. Under the assumption of compressible fluid, the pressure distribution of DCSFD is finally obtained by the numerically iterative method. The film pressure distribution in the outer layer (including the positive and negative pressure zones) obtained from the experimental test agrees well with the numerical prediction, which verifies the validity of the proposed numerical model. In Section 5, the effects of oil temperature, inlet pressure, eccentricity, and whirling frequency on the cavitation in the film are investigated systematically and experimentally. The experimental results indicate that cavitation mainly affect the pressure in the negative pressure zone of the inner and outer film of DCSFD, but has little influence on the pressure in the positive pressure zone. The area of cavitation increased with eccentricity; when the inner eccentricity reached 0.1 or above, the area near the injection hole of film also generated a small zone of negative pressure. The numerical model and the experimental results in this paper are valuable for further research and engineering applications of DCSFD.

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