Performance analysis of a finite noncircular floating ring bearing in turbulent flow regime

Abstract

The present paper investigates the turbulence effect on the steady-state performance of a new variety of journal bearing, i.e. the noncircular floating ring bearing. This particular bearing consists of the journal, floating ring, as well as lower and upper lobes. The shaft and the floating ring are cylindrical while surfaces of the bearing are noncircular. The classical Navier–Stokes equations and continuity equation in cylindrical coordinates are being satisfactorily adapted with the linearized turbulent lubrication model of Ng and Pan. These improved equations are being solved by the finite element method using Galerkin’s technique and an appropriate iteration strategy. The proposed bearing has a length-to-diameter ratio of 1 and operates over different values of the ratio of clearances (i.e. 0.70 and 1.30). The steady-state performance parameters computed are presented in terms of an inner and outer film eccentricity ratios, load-carrying capacity, attitude angle, speed ratio, friction coefficient variable, oil flow, and temperature rise variable for the Reynolds number up to 9000. The present analysis predicts better performance in the turbulent regime as compared to the laminar regime for the noncircular floating ring bearing.

Dynamic behaviors of a high-speed turbocharger rotor on elliptical floating-ring bearings

“…For the first concept of noncircular FRBs (see Figure 1(b)), Soni and Vakharia 16–18 studied its static and dynamic performance using finite element method. However, the nonlinear dynamic response of TC rotor supported by this type of bearings and its ability to reduce the amplitude or suppress sub-synchronous vibrations has not been investigated.…”

“…For the first concept of noncircular FRBs (see Figure 1(b)), Soni and Vakharia [16][17][18] studied its Table 2. Parameters for run-up simulations.…”

“…Unfortunately, the available works on noncircular FRBs are very limited, especially the experimental works concerning the noncircular FRBs have been rarely reported in the literature, with the exception, to the authors' knowledge, of a conference paper by Eling et al, 15 where they found that the multilobe FRBs design is superior in suppressing synchronous and sub-synchronous vibrations and those results have been validated with the experimental results of TC run-up measurements. The theoretical works of Soni and Vakharia [16][17][18] investigated the steady-state and dynamic performance of noncircular cylindrical floating ring journal bearing in which the outer bearing of the FRB is changed in the form of elliptical pattern (see Figure 1(b)) under both laminar and turbulent flow conditions. The analysis results revealed that the steady-state and dynamic performance of this type of bearings are superior to the plain cylindrical FRB.…”

“…For the lobed outer clearance in the noncircular version of the FRB, i.e. the first concept of elliptical FRBs (see Figure 1(b)), Soni and Vakharia [16][17][18] have studied its steady-state and dynamic performance while for another modified version of the plain cylindrical FRBs in which both the inner and outer films of the cylindrical FRBs are changed in the form of elliptical pattern, i.e. the second concept of elliptical FRBs (see Figure 1(c)), the corresponding research has not yet been reported to the authors' knowledge.…”

The effect of three-lobed bearing shapes in floating-ring bearings on the nonlinear oscillations of high-speed rotors

“…Unfortunately the available works on non-circular FRBs are very few, with the exception, to the best of the authors’ knowledge, of the theoretical works of Soni and Vakharia 19–21 and the experimental works of Eling et al. 22 Soni and Vakharia 19–21 investigated the steady-state and dynamic performance of non-circular FRBs in which the outer bearings of the FRBs are changed in the form of elliptical pattern with finite element method (FEM). The analysis results revealed that the steady-state and dynamic performance of this type of FRBs are superior to the plain cylindrical FRBs.…”