Investigación numérica de las condiciones de lubricación en chumaceras hidrodinámicas con el efecto del desalineamiento del eje

Abstract

Investigación numérica de las condiciones de lubricación en chumaceras hidrodinámicas con el efecto del desalineamiento del eje

Fluid Film Bearings and CFD Modeling: A Review

“…The pressure field and the static and dynamic parameters of a bearing can be determined according to the short and long bearing theories, but each considers only a pressure gradient in one coordinate system [8,[12][13][14][15][17][18][19][20]; therefore, the static and dynamic parameters are an excellent approximation. The pressure field of a finite bearing is more reliable because it considers both pressure gradients; however, its computation is not easy (see Equation ( 22)), even though the analysis is considered to be in the steady state.…”

“…Using numerical methods, such as the finite difference method (FDM) [12][13][14][15][16][17] and the finite element method (FEM) [18][19][20], the Reynolds equation is solved; later, the static and dynamic characteristics of the journal bearings are determined to carry out a stability analysis. Usually, in the steady state, from a given eccentricity ratio ε, the attitude angle φ is iteratively determined until the equilibrium condition of Equation ( 11) is achieved.…”

“…The FDM and FEM are widely used to determine the static and dynamic characteristics of journal bearings through the linear perturbation of the position and velocity. Goodwin [12] and Antonio [14] determined the dynamic coefficients by using the FDM to solve pressure gradients and numerical differentiation models, respectively. Sayed [17] used the same methodology and performed curve fitting to obtain the polynomial expressions of the force components and damping coefficients.…”

“…Therefore, the fluid film thickness is no longer uniform in the axial direction (Figure 20) because it decreases at the ends compared to the fluid film thickness at the bearing's center [87]. The change in the fluid film thickness modifies the pressure distribution and increases the maximum pressure, thus producing a concentration of effort at the ends and changes in stability threshold [14].…”

“…Therefore, the fluid film thickness is no longer uniform in the axial direction (Figure 20) because it decreases at the ends compared to the fluid film thickness at the bearing's center [87]. The change in the fluid film thickness modifies the pressure distribution and increases the maximum pressure, thus producing a concentration of effort at the ends and changes in stability threshold [14]. The effects of the misalignment moment and misalignment direction angle were analyzed experimentally and numerically by Pierre [85]; he observed that the maximum temperature of the lubricant was located at the ends of the bearing, where the minimum fluid film thickness was found.…”