Unsteady Flow Produced by Oscillations of Eccentric Rotating Disks

Abstract

While the disks are initially rotating eccentrically, the unsteady flow caused by their oscillations in their own planes and in the opposite directions is studied. The analytical solutions to the problem are obtained for both small and large times, and thus the velocity field is determined for every value of time. The variations of all the parameters on the flow are scrutinized by means of the graphical representations. In particular, the effect of the ratio of the frequency of oscillation to the angular velocity of the disks is analyzed. The dependence of the oscillations in both x-and y-directions on the flow is examined. The influence of the Reynolds number is also investigated.

Periodic flow due to non-torsional oscillations of eccentric rotating porous disks in the presence of a magnetic field

“…After the initial transients decayed, the motion of the fluid starts to be periodic in time. The examination is made after   8  (see [8,9]) at which the flow already attains its periodic state.…”

“…Later, Erdoğan [7] took into account that the disks start to rotate eccentrically and both the disks execute non-torsional oscillations in the same direction while they are initially rotating about a common axis. Ersoy [8] examined the unsteady symmetrical flow due to the non-torsional oscillations of the disks in their own planes and in the opposite directions while they are initially rotating eccentrically. Recently, Ersoy [9] studied the periodic flow produced by nontorsional oscillations of two porous disks in their own planes and in the opposite directions while they are initially rotating about non-coincident axes.…”

Periodic flow due to oscillations of eccentric rotating porous disks

“…In other words, we have C 1 (t) = C 2 (t) = 0 as a consequence of the symmetrical condition. 11 However, C 1 (t) and C 2 (t) are not equal to 0 for the porous disks.…”

“…It is worth noting that the results obtained for large times by Ersoy 11 can be obtained as the special case of the present analysis by taking the suction/injection velocity parameter to be 0. The shear stress components T xz and T yz in the fluid are found as follows:…”

Periodic flow of a second-grade fluid induced by non-torsional oscillations of eccentric rotating disks

“…In the second paper [11], he took into account that the disks start to rotate eccentrically and both the disks execute oscillations in the same direction. Ersoy [12] studied the unsteady symmetrical flow produced by the non-torsional oscillations of the disks in their own planes and in the opposite directions while they are initially rotating about non-coincident axes. Giri et al [13] investigated the flow induced by the effect of a magnetic field in the same geometry.…”