Numerical Simulation of Self-Excited Oscillation of a Turbulent Jet Flowing into a Rectangular Cavity

Abstract

The example of a plane jet flow into a rectangular cavity ("dead end") is used in comparing the capabilities of different approaches to numerical simulation of self-oscillatory turbulent flows characterized by global quasi-periodic oscillation of all flow parameters. The calculations are performed for two flow modes, of which the first one is statistically steady according to the available experimental data, and the second one is self-oscillatory. In both cases, three approaches are used to describe the turbulence, namely, the method of large eddy simulation (LES) in combination with the subgrid model of Smagorinsky, and steady and unsteady Reynolds averaged Navier-Stokes equations (SRANS and URANS) with two well-known differential models of turbulence. In the case of the first flow mode, all three approaches produce qualitatively similar and quantitatively close results. In the case of the second (self-oscillatory) mode, a steady-state solution of Reynolds equations may only be obtained in half the domain using the symmetry boundary conditions; within the framework of the other two approaches, the solutions turn out to be unsteady-state. In so doing, their characteristics calculated using the LES and URANS methods differ significantly from each other; in the case of URANS, they further depend on the model of turbulence employed. The best results as regards the accuracy of prediction of the amplitude-frequency characteristics of self-oscillation are produced by the use of the LES and three-dimensional URANS methods. A similar inference may be made with respect to the mean flow parameters. From this standpoint, the worst results are those obtained from calculations involving the use of the symmetry boundary conditions on the geometric symmetry plane of the flow.

CFD modeling of a self-oscillatory airflow regime in the test ventilated room with plane supply opening

“…The test configuration by Mataoui et al has been already used for numerical data validation, both by the same research group (see [3][4][5][6][7]) and by other research groups [8,9]. Note that most papers presented results obtained with 2D unsteady Reynolds-averaged Navier-Stokes (URANS) approach.…”

Evolution of a confined turbulent jet in a long cylindrical cavity: Homogeneous fluids

“…The oscillatory phenomenon has been identified in numerous studies via direct velocity/pressure measurements, visualization and numerical simulations. [2][3][4] These oscillations lead to strong mixing in the upper part of caverns, and hence their characteristics are of importance for improving SPR performance and decreasing the cost of cavern degassing operations.…”

“…The jet flow (5) inside the cylinder was generated using a conical round nozzle (6) placed at the centre of the hole in the top disk (4). The inner nozzle diameter was d ¼ 0.165 cm while the outer diameter was 0.5 cm, which is less than the diameter of the hole in the glass disk (4). A precision calibrated pump (7) takes water from the larger tank and feeds the nozzle (6) with relatively small volume flux q, generating an intense turbulent jet with a substantial momentum flux J.…”

“…A precision calibrated pump (7) takes water from the larger tank and feeds the nozzle (6) with relatively small volume flux q, generating an intense turbulent jet with a substantial momentum flux J. The same amount of fluid, but with negligible momentum, leaves the cylinder through the hole in the top cover (4). Although most of the measurements were conducted with both ends closed, to better understand the mechanism of jet break up, additional experiments were conducted with different (top/bottom) boundary conditions.…”

Unsteady phenomena of an oscillating turbulent jet flow inside a cavity: Effect of aspect ratio

“…The oscillations of a jet inside a cavity have been the subject of several research works since the pioneering papers of Shakouchi (1981), Shakouchi and Kuzuhara (1982) and Ogab (1985). Then, other researchers have contributed to develop the study of this phenomenon, among them we can mention Maurel (1994), Maurel et al (1996), Villermaux and Hopfinger (1994), Uzol and Camci (2002), Lawson (2001), Lawson et al (2005), Mataoui et al (2001Mataoui et al ( , 2003, Gevici et al, 2003 andDenisikhina et al (2005) who achieved a valuable numerical work using URANS and LES. We also mention again the work of Battaglia et al (1998) dealing with the interaction of a jet in a channel.…”