International Journal of Applied Mechanics and Engineering
Some properties of unsteady unidirectional flows of viscous fluids are discussed for flows impulsively started from rest by a constant pressure gradient in the direction of the flow. Three illustrative examples are given. The first example is the unsteady Poiseuille flow, the second is the unsteady generalized Couette flow and the third is the unsteady flow in a circular pipe. It is found that the...
The model of elastic interior contact between a rough rigid disk and an isotropic plate with thin coating on a smooth cylindrical hole was developed. These investigations allowed us to take into account plastic deformations of a layer of the hole and probability characteristics of surface roughness of a disk. The method of complex potentials (the potentials of Kolosov-Muskhelishvily) and the dependence...
The steady laminar free convection boundary layer over the upper surface of a semi-infinite flat plate which is inclined at a small angle to the horizontal under the combined buoyancy effects of thermal and mass (concentration) effects is theoretically studied in this paper. Series solutions are obtained for both positive and negative inclinations of the plate, valid near the leading edge of the plate...
A regular perturbation analysis is presented for the laminar natural convection flows of micropolar fluids with temperature dependent viscosity: a freely-rising plane plume, the flow above a horizontal line source on an adiabatic surface (a plan wall plume) and the flow adjacent to a vertical uniform flux surface. While these flows have well-known power-law similarity solutions when the fluid viscosity...
We study the flow of granular materials down an inclined plane. We assume steady fully developed conditions. The constitutive relation is that of Rajagopal and Massoudi (1990), where the material parameters are given by the theory of Boyle and Massoudi (1990). We do not consider the effects of ?granular temperature? (a measure of the fluctuating component of the velocity of the grains). The material...
The magnetoconvective flow and heat transfer between a long vertical wavy wall and a parallel flat wall in the presence of applied electric field parallel to gravity, magnetic field normal to gravity and uniform heat source is investigated. Nonlinear equations governing the motion have been solved by linearization technique wherein the flow is assumed to consist of two parts; a mean part and a perturbed...
A mathematical description of a mixture of a Newtonian fluid infused with particulate solids is presented within the context of Mixture Theory. In the absence of any thermal effects, the balance of mass and balance of linear momentum equations for each component are averaged over the cross section of the flow to obtain ordinary differential equations describing developing flow between parallel plates...
The second order perturbation second probabilistic moment analysis of stochastic vibrations problems in the context of the Finite Difference Method (FDM) is presented. The approach can be successfully used in all engineering analyses where FDM modelling of vibrations is appropriate and, in the same time, where certain structural parameters are random variables or fields. The main advantage of the...
A class to exact solutions of equations governing the steady plane flows of an incompressible fluid of variable viscosity are determined using von ? Mises variables. Applications of some of the solutions to the boundary value problems are also indicated.
The thermosolutal instability of Walters' (model B') elastico-viscous rotating fluid in a porous medium is considered in the presence of a uniform magnetic field and varying gravity field. For the case of stationary convection, the solute parameter delays the onset of convection. The system is stable or unstable as gravity increases or decreases in the presence of rotation and magnetic field stabilizes...
The effect of anionic polysaccharide sodium alginate on the rheological properties of gelatin gels at pH values more than isolectric point of gelatin macromolecules has been investigated. The results of rheological measurements within the non-linear viscoelasticity range have been studied using Hershel-Bulkley model and Casson model. The analysis of the rheological curves allows characterizing the...
The effect of cross diffusion and the horizontal gradients of temperature and salinity on double diffusive convection in a fluid saturated densely packed porous medium is investigated using an analytical approach. The condition for the onset of convection through stationary and oscillatory modes has been reported. The effect of Soret, Dufour parameters, and horizontal gradients of temperature and...
Flow past an impulsively started infinite vertical isothermal plate in the presence of thermal radiation effects is studied here. The fluid considered is a gray, absorbing-emitting radiation but a non-scattering medium. It is observed that for an increase in radiation parameter N or the Grashof number Gr, there is a fall in the velocity or temperature, but compared to the no-radiation case, there...
At present there exist several approaches to the formulation of fluids that contain structures. These fluids have various names such as simple microfluids, micropolar fluids, deformable directed fluids, polar fluids, anisotropic fluids, etc. In this paper the steady laminar flow of micropolar fluid in a slot between rotating surfaces of revolution, having a common axis of symmetry, is considered....
An approximate analysis of a two-dimensional flow of an electrically conducting incompressible viscous fluid past an infinite porous plate, stationary or steadily moving in its own plane, is presented under the following conditions: i) suction velocity oscillates about a constant non-zero mean; ii) the free stream velocity oscillating in time about a constant mean; iii) constant heat flux at the plate;...
The paper contains an analysis of the ultimate load and post-failure behaviour of thin-walled orthotropic box-section beams. The problem of post-failure behaviour is solved using the principle of virtual velocities based on the rigid-plastic theory adopted and modified for the purposes of an orthotropic material - displaying strain-hardening phenomenon. The Hill yield criterion is applied in order...
This paper presents the optimisation of an octopus type car rim in which first critical zones have been found and then optimum thickness has been investigated using an elasto-plastic analysis. In this study, three dimensional finite elements method has been used for conducting elasto-plastic analysis. In the finite element analysis, the elements forming the meshes are hexahedral linear elements with...
The increase in vehicle speed, unsuitable road conditions and comfort demand have resulted in extensive research on vibration control of vehicle systems. In this paper, firstly, a specific passenger car (with a conventional suspension system) was considered including the vertical body displacements for sinusoidal road functions. Secondly, passive and active vibration control cases are studied to eliminate...
The partial differential equations governing the unsteady convective flow of a fluid have been solved exactly when the flow takes place near an infinite vertical plate in a system rotating with a constant angular velocity. Exact analytical solutions for the boundary layer velocity variables and skin friction components have been presented separately for the cases of fluids whose Prandtl numbers are...
On the basis of the Stokes microcontinuum theory and the Christensen stochastic model, a theoretical study of squeeze film performance for isotropic rough rectangular plates with couple stress fluids as lubricants is presented. A stochastic non-Newtonian Reynolds-type equation is derived and solved analytically for the mean film presure distribution. Squeeze film characteristics are then evaluated...