Machine learning-based performance analysis of two-axial-groove hydrodynamic journal bearings

Author(s):  
Biswajit Roy ◽  
Sudip Dey

The precise prediction of a rotor against instability is needed for avoiding the degradation or failure of the system’s performance due to the parametric variabilities of a bearing system. In general, the design of the journal bearing is framed based on the deterministic theoretical analysis. To map the precise prediction of hydrodynamic performance, it is needed to include the uncertain effect of input parameters on the output behavior of the journal bearing. This paper presents the uncertain hydrodynamic analysis of a two-axial-groove journal bearing including randomness in bearing oil viscosity and supply pressure. To simulate the uncertainty in the input parameters, the Monte Carlo simulation is carried out. A support vector machine is employed as a metamodel to increase the computational efficiency. Both individual and compound effects of uncertainties in the input parameters are studied to quantify their effect on the steady-state and dynamic characteristics of the bearing.

Author(s):  
Sanyam Sharma ◽  
Chimata M Krishna

The plain circular journal bearings are not found to be stable by researchers when used in high speed rotating machineries. Hence, extensive research in the study of stability characteristics of non-circular bearings or lobed bearings assumed importance, of late. Present article deals with the stability analysis of non-circular offset bearing by taking selected set of input and output parameters. Modified Reynolds equation for micropolar lubricated rigid journal bearing system is solved using finite element method. Two kinds of input parameters namely, offset factors (0.2, 0.4) and aspect ratios (1.6, 2.0) have been selected for the study. The important output characteristics such as load, critical mass, whirl frequency ratio, and threshold speed are computed and plotted for various set of values of input parameters. The results obtained indicate that micropolar lubricated circular offset bearing is highly stable for higher offset factor and higher aspect ratio.


2010 ◽  
Vol 297-301 ◽  
pp. 618-623 ◽  
Author(s):  
S. Boubendir ◽  
Salah Larbi ◽  
Rachid Bennacer

In this work the influence of thermal effects on the performance of a finite porous journal bearing has been investigated using a thermo-hydrodynamic analysis. The Reynolds equation of thin viscous films is modified taking into account the oil leakage into the porous matrix, by applying Darcy’s law to determine the fluid flow in the porous media. The governing equations were solved numerically using the finite difference approach. Obtained result show a reduction in the performance of journal bearings when the thermal effects are accounted for and, this reduction is greater when the load capacity is significant.


2013 ◽  
Vol 315 ◽  
pp. 809-814 ◽  
Author(s):  
Mohamad Ali Ahmad ◽  
Salmiah Kasolang ◽  
Rob Dwyer-Joyce ◽  
Nik Rosli Abdullah

In hydrodynamic lubrication, the pressure condition of the fluid is critical to ensure good performance of the lubricated machine elements such as journal bearings. In the present study, an experimental work was conducted to determine the effect of oil supply pressure on pressure profile around the circumference of a journal bearing. A journal diameter of 100mm with a ½ length-to-diameter ratio was used. The oil supply pressure was set at three different values (0.3, 0.5, 0.7 Mpa) and the circumferential pressure results for 400, 600 and 800 RPM at different radial loads were obtained. It was observed that the maximum pressure values were affected by changes in oil supply pressure.


Author(s):  
Biswajit Roy ◽  
Lintu Roy ◽  
Sudip Dey

Abstract This paper presents the effect of eccentricity and surface roughness on the probabilistic performance of two axial groove hydrodynamic journal bearing. In general, it is difficult to quantify experimentally the variabilities involved in dynamic responses of the hydrodynamic bearing due to the randomness involved in surface asperity and eccentricity ratio. The deterministic models available for the analysis of the bearings are not capable to include such uncertainties. These uncertainties arise from the manufacturing imperfections, misalignment of the bearing, frictional wear, uncertain operating condition, model inaccuracy. To simulate such variabilities, Monte Carlo simulation (MCS) is carried out. Stochastic steady-state and dynamic coefficients are obtained by solving the Reynolds equation using the surrogate-based finite difference method. Sensitivity analysis of the performance parameters with respect to stochastic input parameters is portrayed. The moving least square (MLS) model is constructed as the surrogate to increase the computational efficiency. The significant influences of stochastic input parameters such as surface roughness and eccentricity ratio are observed on the random hydrodynamic performance of two axial groove journal bearing.


2004 ◽  
Vol 126 (3) ◽  
pp. 542-546 ◽  
Author(s):  
Z.-C. Peng ◽  
M. M. Khonsari

A model is developed to predict the hydrodynamic performance of a foil journal bearing. The model accounts for both the compressibility of air and the compliance of the bearing surface. A series of predictions of the load-carrying capacity based on the numerical solution for pressure is presented that cover a wide range of operating speeds. The results show good agreement with existing experimental data.


Author(s):  
D Dowson ◽  
C M Taylor ◽  
A A S Miranda

Analyses of liquid film journal bearings rarely consider the reformation of the lubricant film. This reformation normally takes place in the vicinity of a supply groove and is influenced by, amongst other parameters, the lubricant supply pressure. In a previous paper the authors have described in detail the implementation of an algorithm to locate automatically and efficiently the locus of film rupture and reformation boundaries using a digital computer. In the present paper results are presented for a wide range of important variables. In particular, the prediction of lubricant supply rate is studied carefully and compared with data presented in a widely used design aid which does not account in detail for the influence of film reformation.


2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Jun Sun ◽  
Mei Deng ◽  
Yonghong Fu ◽  
Changlin Gui

Journal misalignment exists generally in journal bearings. When severe journal misalignment takes place, the minimum film thickness of journal bearings reduces greatly. In this condition, the surface roughness, the oil viscosity-pressure relationship (VPR), and the thermal effect have obvious effects on hydrodynamic lubrication performance of misaligned bearings. In this paper, the oil film pressure, oil film temperature, load-carrying capacity, end leakage flow rate, frictional coefficient, and misalignment moment of a journal bearing with different angles of journal misalignment and surface roughness, and considering oil VPR and thermal effect, were calculated based on the generalized Reynolds equation, energy equation, and solid heat conduction equation. The results show that the oil VPR and surface roughness have a significant effect on the lubrication of misaligned journal bearings under large eccentricity ratio. The thermal effect will affect obviously the lubrication of misaligned journal bearings when eccentricity ratio and angle of journal misalignment are all large. In the present design, the size of the journal bearing is compact more and more, and the eccentricity ratio and angle of journal misalignment are usually large in operating conditions. Therefore, it is necessary to take the effects of journal misalignment, surface roughness, oil VPR, and thermal effect into account in the design and analyses of journal bearings.


2018 ◽  
Vol 204 ◽  
pp. 04006
Author(s):  
Muchammad ◽  
Mohammad Tauviqirrahman ◽  
Rizqy Amanullah Akbar ◽  
Fuad Hilmy ◽  
Jamari

Surface texturing of the lubricated bearing has proven to improve the hydrodynamic performance. The present paper analyzed the effect of surface texturing on the covergent journal bearing with computational fluid dynamic (CFD) approach. The eccentricity ratio, the ratio of textured depth and surface area are the main parameter research. It was shown that for the eccentricity ratio of 0.2, the surface texturing improves the hydrodynamic performance lubrication by increasing the load support. On the otherwise, for the eccentricity ratio of 0.8, the surface texturing does not improve the lubrication performance, even under certain condition, it decreases the lubrication performance of journal bearing.


2019 ◽  
Vol 8 (1) ◽  
pp. 397-406 ◽  
Author(s):  
Vishwanath B. Awati ◽  
Ashwini Kengangutti

Abstract The paper presents, surface roughness effect for thermo-hydrodynamic analysis of journal bearings extended to couple stress lubricants with high polymer additives. A modified energy equation is simultaneously solved with heat transfer equation as well as modified Reynolds equation by using Multigrid method. The effects of couple stress and surface roughness on the performances of a finite journal bearing are presented in detail. Further, it is shown that lubricants with couple stress and surface roughness, not only increases the load capacity and decreases the friction coefficient, but also generates a lower bearing temperature field. Thus, the lubricant with couple stress improves the performance of journal bearings. The characteristics of bearing are compared with numerical results.


Author(s):  
S. Strzelecki ◽  
H. Kapusta ◽  
J. Swiatek

Two-lobe journal bearings are applied in the responsible bearing systems of steam turbines, turbogenerators and compressors. As compare to the bearing with the cylindrical bush they have better stability in the range of higher rotational velocities and loads simultaneously assuring very good cooling conditions for the oil film. For the two-lobe journal bearing the oil film pressure, temperature and viscosity distributions have been obtained by iterative solution of the Reynolds’, energy and viscosity equations. An effect of supplied oil pressure on the maximum oil film temperature was investigated.


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