Visualisation studies of the transition regime flow in a channel of varying cross section under the influence of Coriolis force

Nonlinear stability characteristics of the pressure‐gradient driven flow between walls in a rotating system under the influence of the Coriolis force

“…The method of investigation that is a well established in fluid dynamics is to follow the evolution of arbitrary disturbances in a state of the flow just prior to transition. Previous work on this geometry are the works of G.MARLIANI et al [14], Kyung-Soo Yang, John Kim [16], Peter G. Bainesi, Sharan J. Majumdar et al [17], Venkatesa I. Vasanta Ram and Maren Schmidts [18], Stéphane Leblanc and Claude Cambon [20], P. Henrik Alfredson and Hakan Persson [36], James P. Johnston, Robert M. Halleent et al [37], G. S. Benton and D. Boyer [38], Dietrich K. Lezius and James P. Johnston [40], Per A. Elofsson and P. Henrik Alfredsson [51].…”

“…A salient feature of transition under the influence of Coriolis force, say in a channel, is that depending upon the values of set of the parameters, which are the Reynolds number and the rotation number, the flow just past transition can exhibit a state of apparent chaos or be highly ordered. An experimental example taken from [14] is reproduced below. The purpose of this work is investigation into the nature of the flow immediately past transition through studying details of the dynamics in the relatively simple geometry of the channel flow on a rotating system.…”

“…The mechanics of the resulting growing disturbance known as Tollmien-Schlichting wave was described in [17] which is a physical mechanism for the two-dimensional instability of a Blasius boundary layer and similar flows, and, linear and nonlinear stability of Tollmien-Schlichting waves in the Blasius boundary layer is explained in [27]. The flow visualization studies of the transition regime showing up regularly spaced rolls of longitudinal vortices in a channel of varying cross section under the influence of the Coriolis force were explained in [14,18]. Leblanc and Cambon also discussed three-dimensional instabilities of plane channel flows under the influence of Coriolis force in [20].…”

Modeling of Flow Burst, Flow Timing in Lab‐on‐a‐CD Systems and Its Application in Digital Chemical Analysis

“…where C is a constant which is equivalent to the reduced pressure gradient, G * , in reference [18]. At z = r 2 -r 1 , the outlet of the microchannel, the pressure could be assumed to be zero.…”

“…Because of the existence of the two-body forces, centrifugal flows can become quite complex. Macroscale flows in rotating channels have been investigated experimentally by Benton and Boyer [17], and Ram [18], theoretically by Baura [19] and Benton [20], and numerically by Yang and Kim [21], and Lei and Hsu [22]. Lei and Hsu [22] defined two dimensionless numbers: the rotational Reynolds number, R x (= x a 2 /m, where x, a, and m are the angular velocity of rotation, the characteristic size of the channel and the kinematic viscosity of the fluid, respectively), and the reduced pressure gradient, G (= G * a 3 / q m 2 , where G * is the reduced pressure gradient and q is the Figure 1.…”