Article
Comparative effects of forces acting on swirling annular liquid sheets
ASME Early Career Technical Journal
(2012)
Abstract
The respective effects of the multiple forces that control the development of swirling liquid sheets injected from an annular nozzle into quiescent surrounding medium are studied. These forces include inertia, viscous, gravity, pressure, surface tension, centrifugal and Coriolis forces. In order to simplify the mathematical formulation of the inherently complex transient, three-dimensional problem considered, a body-fitted coordinate system is employed. Use of these coordinates enables the transformation of the system partial differential equations, consisting of mass and momentum conservation equations with appropriate boundary conditions, into ordinary differential equations. These equations are then solved numerically to yield sheet trajectory, thickness, and velocity, for a given set of mass flow rate and liquid-swirler angle. By eliminating any of the acting forces from the governing equations, one at a time, the individual influence of each force on sheet evolution characteristics is isolated and evaluated. It is found that centrifugal and Coriolis forces play significant roles in determining the resulting configuration and flow velocities of a developing swirling annular liquid sheet. Whereas centrifugal forces act to increase the developing sheet radius and angle, Coriolis force has opposite effects. The sheet thickness variation is independent of Coriolis force but sheet thickness increases significantly if the centrifugal force is not taken into account. Neglecting either of the centrifugal or Coriolis forces causes the sheet stream-wise velocity to decrease. In the absence of Coriolis force, the sheet swirl velocity remains constant at its initial value while the centrifugal force has the tendency to diminish swirl velocity. For the range of parameters investigated, gravitational acceleration, surface tension, and interfacial friction forces exhibit minimal impact on the formation of a swirling liquid sheet. The present assessment of the influence of various forces on the injected sheet behavior may be applied to guide efficient design of swirl injectors.
Keywords
- swirling annular liquid sheets
Disciplines
Publication Date
November, 2012
Citation Information
Mohammed Ali and E. A. Ibrahim. "Comparative effects of forces acting on swirling annular liquid sheets" ASME Early Career Technical Journal Vol. 11 Iss. 1 (2012) p. 228 - 235 Available at: http://works.bepress.com/mohammedali/48/