Two-Fluid Flow Between Rotating Annular Disks

Abstract

The general hydrodynamic behavior at small clearance Reynolds numbers of two fluids of different density and viscosity occupying the finite annular space between a rotating and stationary disk is explored using a simplified version of the Navier-Stokes equations which retains only the centrifugal force portion of the inertia terms. A criterion for selecting the annular flow fields that are compatible with physical reservoirs is established and then used to determine the conditions under which two-fluid flows in the annulus might be expected for specific fluid combinations.

Hydrodynamic Lubricant Film Separation During Codirectional and Counter-Directional Rotations of Disengaged Wet Clutch Packs

“…The study conducted by Yuan et al [14] showed that the oil film, once ruptured, is swept away by the faster of the two rotating annular surfaces over a cavity of air that extends to the conjunctional external radius. This is supported by the analysis of Zweig and Sneck [15]. Additionally, Yuan et al [14] showed that the rotational speed of both surfaces is critical in determining the position of lubricant film rupture.…”

“…Integrating equation (13) with respect to the radius yields equations (14) and (15), where equation (15) describes the pressure at any radial location in the lubricant film:…”

“…where is the radius of curvature of the free boundary film at separation and ∆ is the pressure change across the transition between the full film and swept film/cavity. When these boundary conditions are applied to equation (15), equations (18) and (19) can be obtained:…”

Numerical study of flow and heat transfer in a porous medium between two stretchable disks using quasi-linearization method

“…They also discussed the uniform suction effects through the rotating disk. Hydrodynamic behavior of two fluids at low Reynolds number, both having different density and viscosity between a rotating and a stationary disk was explored by Zweig et al [7]. Qayyum et al [8] discussed the problem of non-steady axisymmetric Jeffrey fluid flow between two parallel disks.…”

Oil film separation and drag torque in disengaged wet brakes

“…Observation of lubricant film rupture in rotary components, separated by a thin lubricant film shows a single free boundary is often formed, with the remaining volume of lubricant swept away by the rotating surface. Examples of this are reported for wet clutches [8,13,14], as well as for rotary face seals [15,16]. This indicates that wet brakes and clutch packs should use a separation (Prandtl-Hopkins incipient reverse flow) boundary conditions rather than the commonly employed cavitation boundary conditions.…”