The deformations and stresses during squeeze flows are evaluated for a wider class of materials than previously covered in articles on this subject. These include generalised Newtonian fluids, yield stress fluids, as well as elastic and viscoelastic materials. Wherever possible, results are given in a compact mathematical form. The effect of different boundary conditions (no slip, perfect slip and partial slip) and how these interact with different types of material behaviour to give a variety of macroscopic responses is also discussed. The significance of this in using squeeze flow as a rheometry method is highlighted and a state-of-the-art view of squeeze flow rheometry is given.

Squeeze flow theory and applications to rheometry: A review

The present theoretical analysis is to investigate the effect of non-Newtonian pseudoplastic lubricant (lubricant blended with viscosity index improver and viscosity thickener)–Rabinowitsch fluid model on the performance of externally pressurized hydrostatic thrust bearing. The expression for pressure has been derived using an energy integral approach. The load capacity and frictional torque of the bearing have also been numerically calculated for various values of viscosity index improver along with the centrifugal effects. The results so obtained are compared and found to be in good agreement with the earlier theoretical and practical results of Dowson, and the effect of viscosity index improver is also analyzed.

On the Steady Performance of Hydrostatic Thrust Bearing: Rabinowitsch Fluid Model

A Riga plate is an electromagnetic actuator which comprises permanent magnets and alternating electrodes placed on a plane surface. The present article investigates the influence of viscous and Joule heating (Ohmic dissipation) in the magnetohydrodynamic squeezing flow, heat and mass transfer between two Riga plates. A non-Fourier (Cattaneo–Christov) heat flux model is employed which generalizes the classical Fourier law to incorporate thermal relaxation time. Via suitable transformations, the governing partial differential conservation equations and boundary conditions are non-dimensionalized. The resulting nonlinear ordinary differential boundary value problem is well posed and is solved analytically by the variational parameter method (VPM). Validation of the solutions is included for the special case of non-dissipative flow. Extensive graphical illustrations are presented for the effects of squeeze parameter, magnetic field parameter, modified Hartmann number, radiative parameter, thermal Biot number, concentration Biot number, Eckert number, length parameter, Schmidt number and chemical reaction parameter on the velocity, temperature and concentration distributions. Additionally, the influence of selected parameters on reduced skin friction, Nusselt number and Sherwood number are tabulated. An error analysis is also included for the VPM solutions. Detailed interpretation of the results is provided. The study is relevant to smart lubrication systems in biomechanical engineering and sensor design.

/pdf/viscous-dissipation-and-joule-heating-effects-in-non-fourier-2t8tm1o846.pdf

Viscous Dissipation and Joule Heating Effects in Non-Fourier MHD Squeezing Flow, Heat and Mass Transfer Between Riga Plates with Thermal Radiation: Variational Parameter Method Solutions

Non-Newtonian squeeze film characteristics between parallel annular disks: Rabinowitsch fluid model

The present work is committed to study the influence of dissipation and Joule heating on the magnetohydrodynamic squeezing flow between two Riga plates with Cattaneo–Christov heat flux. Riga plate is known as an electromagnetic actuator which comprises of permanent magnets and alternating electrodes placed on a plane surface. A non-Fourier (Cattaneo–Christov) heat flux by considering thermal relaxation time to Fourier’s law is implemented to analyse the features of heat transfer. The resulting system of nonlinear ordinary differential equations together with the boundary conditions is solved numerically by the RK Fehlberg method with shooting technique. The effects of diverse parameters on the flow, energy and concentrations are discussed and displayed graphically. Additionally, the influence of selected parameters on reduced skin friction, Nusselt number and Sherwood number is also graphically illustrated. It is noticed that there is a significant increase in temperature of the fluid with rising viscous dissipation and Joule dissipation. In addition, increasing squeezing parameter and magnetic field parameter results a strong reduction in skin friction at the upper Riga plate. A consistent growth in Nusselt number is observed with rising Eckert number, length parameter, radiation parameter and thermal Biot number.

Combined effect of viscous dissipation and Joule heating on MHD flow past a Riga plate with Cattaneo–Christov heat flux

An analysis is presented for the laminar squeeze flow of an incompressible powerlaw fluid between parallel plane annuli using the modified lubrication theory and energy integral method. The local and the convective inertia of the flow are considered in the investigation. Analytical expressions for the load carrying capacity of the squeeze film are obtained using, both the methods and are compared with those based on the assumption of inertialess flow. It is observed that the inertia correction in the load carrying capacity is more significant for pseudo-plastic fluids, n < 1.

Fluid Inertia Effects in a Non-Newtonian Squeeze Film Between Two Plane Annuli

Curved squeeze film with inertial effects — energy integral approach

In this paper, the magnetic effects on the Newtonian squeeze film between two circular parallel plates, containing a single central air bubble of cylindrical shape are theoretically investigated A uniform magnetic field is applied perpendicular to the circular plates, which are in sinusoidal relative motion, and fluid film inertia effects are included in the analysis Assuming an ideal gas under isothermal condition for an air bubble, a nonlinear differential equation for the bubble radius is obtained by approximating the momentum equation governing the magnetohydrodynamic squeeze film by the mean value averaged across the film thickness Approximate analytical solutions for the air bubble radius, pressure distribution, and squeeze film force are determined by a perturbation method for small amplitude of sinusoidal motion and are compared with the numerical solution obtained by solving the nonlinear differential equation The combined effects of air bubble, fluid film inertia, and magnetic field on the squeeze film force are analyzed

Magnetohydrodynamic Squeeze Film Characteristics Between Parallel Circular Plates Containing a Single Central Air Bubble in the Inertial Flow Regime

The squeeze film force in a circular Newtonian squeeze film has been theoretically predicted by using the elliptical velocity profile assumption in the squeeze film by three different approximation methods. As examples, the numerical results for the sinusoidal squeeze motion, constant velocity squeezing state, and constant force squeezing state have been obtained

Squeeze Film Force Using an Elliptical Velocity Profile

The laminar squeeze flow of a viscous incompressible fluid between a flat circular disk and an axisymmetric curved disk of arbitrary shape is investigated theoretically using modified lubrication theory. The characteristics of squeeze film are investigated through inertia and curvature effects on the normal force exerted on the upper curved moving disk described by an exponential function for the sinusoidal squeeze motion. The constant force squeezing state is also examined. It has been observed that the load carrying capacity of the curved squeeze film is strongly influenced by the curvature and inertia effects.

P. Vimala

Papers

Fluid Inertia Effects in a Non-Newtonian Squeeze Film Between Two Plane Annuli

Curved squeeze film with inertial effects — energy integral approach

Magnetohydrodynamic Squeeze Film Characteristics Between Parallel Circular Plates Containing a Single Central Air Bubble in the Inertial Flow Regime

Squeeze Film Force Using an Elliptical Velocity Profile

Theoretical Investigation of Unsteady Squeeze Flow in a Curved Newtonian Squeeze Film