Squeeze film characteristics of conical bearings operating with non-Newtonian lubricants – Rabinowitsch fluid model

Abstract

Purpose -The purpose of this paper is to present a theoretical study of non-Newtonian effects in conical squeeze-film plates that is based on the Rabinowitsch fluid model. Design/methodology/approach -A non-linear, modified Reynolds equation accounting for the non-Newtonian properties following the cubic stress law equation is derived. Through a small perturbation method, first-order closed-form solutions are obtained. Findings -It is found that the non-Newtonian properties of dilatant fluids increase the load capacity and lengthen the response time as compared to the case using a Newtonian lubricant; however, the non-Newtonian behaviors of pseudoplastic lubricants result in reverse influences. Originality/value -Numerical tables for squeeze-film loads of conical plates are also provided for engineering applications.

Effect of viscosity variation on non-Newtonian lubrication of squeeze film conical bearing having porous wall operating with Rabinowitsch fluid model

“…Variation of the load-carrying capacity L* with film height h* for different values of ω and θ with Hp=0.1,Rp=0.1, and Q=0.25 is presented in Figure 7. It is found that the load capacity L* decreases for increasing values of film thickness h*. Further, the dimensionless load capacity L* decreases with increasing values of θ with ω and agrees very well with the results of Hsu et al., 6 which has been shown in Figure 7.

Figure 6.Variation of the load-carrying capacity L* with film height h* for different ω, H p , and R p with

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“…Increasing the viscosity variation decreases the film pressure and it agrees with the study of Siddangouda et al. 6

Figure 2.Variation of the dimensionless film pressure P* with x* for different values of ω and Q with h*=0.3, Hp=0.1,Rp=0.1, and θ = 45°.

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“…Lubrication theory is considered as per the study by Hsu et al. 6 The basic equations of motion and equation of continuity in axially cylindrical coordinates in the most generalized form for non-Newtonian fluid is written as which are solved using the boundary conditions where u¯ and w¯ are the velocity components in x¯ and z¯ directions respectively, and h¯ is the film thickness.…”

Effect of non-Newtonian lubrication of squeeze film conical bearing with the porous wall operating with Rabinowitsch fluid model

“…It is hopeful to provide comparisons and numerical tables for dimensionless load-carrying capacity with different half cone angle. The simulated data from Table 1 to 4 are compared with Hsu et al 9 for the non-porous case. Tables 1 and 2…”

Non-newtonian Rabinowitsch Fluid Effects on the Lubrication Performances of Sine Film Thrust Bearings

“…This non-Newtonian Rabinowitsch fluid model is applicable to dilatant lubricants for 0 n < , to Newtonian lubricants for 0 n = , and to pseudo-plastic lubricants for 0 n > . Many studies have applied this model to investigate the thin film lubrication systems, for example, the squeeze film bearings by Lin [8] and Hsu et al [9], the hydrostatic bearings by Sharma et al [10], the journal bearings by Bourging and Gay [11], and the inclined plane slider bearings by Lin [12]. According to their results, the influences of non-Newtonian Rabinowitsch fluids on the lubrication performances of the squeeze film bearings, the hydrostatic bearings, the journal bearings and the inclined plane slider bearings are significantly apparent.…”