Numerical Simulation of a Swirling Jet Behind a Circular Disk Last Updated: 8 June 2011 People: Dr. H.T. Toh
Swirling jets and bluff-body wakes are widely used in industries to enhance mixing processes such as those found in industrial burners, fluid mixers and gas turbine combustors. Traditionally, swirling jet and bluff-body wake without swirl are studied independently. It is only recently that the research community has begun to look into the combined effects of a swirling jet and a bluff body. Although experimental studies of the combined effects of a swirling jet and a bluff body have been performed by Huang and Tsai1-2, numerical simulation of such effects is scarce in the literature. The objective of this project is to study the turbulent flow field of a swirling jet behind a circular disk using LES (Large eddy simulation). To this end, the unsteady 3D incompressible Navier-Stokes equations are solved numerically using an artificial compressibility method with dual-time stepping. Both pseudo time and physical time are marched implicitly. The convective terms in the equation are discretized using a fifth-order WENO (Weighted Essentially Non-oscillatory ) scheme whereas the viscous terms are discretized using a fourth-order central difference scheme. To avoid solving a large block banded matrix resulting from the implicit time scheme, the LU-SSOR scheme of Yoon and Jameson3 is used. Since the flow solver is based on a Cartesian grid, the concept of immersed boundary is used to represent the circular geometry of the disk.
Reference
1. Huang, R. F. and Tsai, F.C., “Observations of swirling flows behind circular disks,” AIAA Journal, Vol. 39, No. 6, 2001, pp. 1106-1112.
2. Huang, R. F. and Tsai, F.C., “Flow and mixing characteristics of swirling wakes in blockage-effect regime,” Journal of Wind Engineering and Industrial Aerodynamics,Vol. 92, 2004, pp 199-214.
3. Yoon, S. and Jameson, A., “A multigrid LU-SSOR scheme for approximate Newton iteration applied to Euler equations,” NASA Contract Report 179524, Sept. 1986.
Publication 1. Toh, H.T., Huang, R.F., and Chern, M.J. 2008 “Direct simulation of a swirling jet behind a circular disk..” Journal of Mechanical Engineering Science 223, 1127-1139 [Full Text]
Tel: (886)-2-2737-6496 Fax: (886)-2-2737-6460 E-mail: mjchern@mail.ntust.edu.tw
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