Showing papers by "R. Usha published in 1999"
TL;DR: In this article, a particle-fluid suspension model is applied to the problem of pulsatile blood flow through a circular tube under the influence of body acceleration, and analytic expressions for axial velocity for both fluid and particle phase, fluid acceleration, wall shear stress and instantaneous flow rate have been obtained.
Abstract: A particle-fluid suspension model is applied to the problem of pulsatile blood flow through a circular tube under the influence of body acceleration. With the help of finite Hankel and Laplace transforms, analytic expressions for axial velocity for both fluid and particle phase, fluid acceleration, wall shear stress and instantaneous flow rate have been obtained. It is observed that the solutions can be used for all feasible values of pulsatile and body acceleration Reynolds numbers Rp and Rb. Using physiological data, the following qualitative and quantitative results have been obtained. The amplitude Qb of instantaneous flow rate due to body acceleration decreases as the tube radius decreases. The effect of the volume fraction of particle C on Qb is to increase it with increase of C in arteriole and to decrease Qb as C increases in coronary and femoral arteries. The maximum of the axial velocity and fluid acceleration shifts from the axis of the tube to the vicinity of the tube wall as the tube diameter increases. The effect of C on the velocity and acceleration are nonuniform. The wall shear amplitude \(\tau_b\) due to body acceleration increases as the tube diameter decreases from femoral to coronary and a further decrease in the tube diameter leads to a decrease in \(\tau_b\). The effects of C on \(\tau_b\) are again nonuniform.
32 citations
TL;DR: 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, were theoretically investigated, and the authors derived analytical solutions for the bubble radius, pressure distribution, and squeeze film force.
Abstract: 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
8 citations