Squeeze-Film Behavior in Porous Circular Disks

Abstract

The squeeze film behavior between two circular disks is analyzed when one disk has a porous facing and approaches the other disk with uniform velocity. The modified Reynolds equation governs the pressure in the film region while the pressure in the porous facing satisfies the Laplace equation. These equations are solved in a closed form and expressions are derived for pressure distribution, load capacity, and time of approach for the plates in terms of Fourier-Bessel series. It is found that an enhanced value for the permeability parameter diminishes the pressure over the entire disk and also evens out the pressure distribution; however, there is an adverse effect on the load capacity and time of approach. Unlike in the nonporous case, the entire fluid can be squeezed out in a finite time resulting in actual contact of the disks. The porous effects are shown to predominate at very low film thickness values.

Surface roughness effects on squeeze film behavior in porous circular disks with couple stress fluid

“…The physical reasons are given by Prakash and Tiwari (1982) while explaining the squeeze film characteristics of rough porous rectangular plates and also these results confirm the experimental observations in (Wu 1978) that loadW decreases for increasing values of permeability parameter ψ. This trend is preserved for all values of roughness parameter C. The results of Murti (1974) which correspond to C → 0, β = 0 and τ → ∞ have been shown in the Figs. 2 and 4 (lines without symbols).…”

“…In the limiting case, C → 0, β = 0, and τ → ∞, the present analyses reduce to classical case (i.e. Newtonian and smooth surface) studied by Murti (1974). Figure 2 shows the variation of non-dimensional loadW with permeability parameter ψ for different roughness parameter C. As ψ increases the load carrying capacitȳ W decreases for both types of roughness patterns.…”

“…Besides engineering applications, their detail study is of immense use in understanding lubrication aspects of Synovial joints. Wu (1972) and Murti (1974) have given very useful predictions in respect of porous bearings. The analysis of squeeze film bearings is made by many researchers for Newtonian lubricants based on the assumption of perfectly smooth bearing surfaces.…”

Ferrofluid Lubricated Porous Squeeze-Film Bearing with the Modified Condition of Pressure Continuity at the Film-Porous Interface

“…(3) When p = p * (conventional assumption); that is, when the pressure in the film region and porous region are equal, then P is zero. The above case (3) reduces the present analysis to that of reference [18] for conventional lubricant.…”

“…In all above studies, Reynolds equation is derived or solved either by assuming Morgan-Cameron approximation (that the pressure in the porous region can be replaced by the average pressure with respect to the bearing wall thickness) [15] or by directly comparing pressure at the film-porous interface [16][17][18][19]. However, due to squeezing, vibration, etc.…”