Numerical simulation of incinerator overfire mixing

Abstract Recognizing the benefits of optimizing the design and operation of the overfire processes in mass burn incinerators, the potential for numerical simulation of overfire mixing using 2-D isothermal flow studies is explored. A finite difference method (FD) and a finite element method (FEM) are applied to the solution of model equations incorporating simplifications typically employed in utility furnace simulations. Mesh stability of the FD and the FEM solutions is studied. The FEM appears better equipped to deal with the discretization challenges posed by incinerator configurations than FD. Sensitivity of the FEM solutions to boundary conditions as well as artificial stability enhancing measures is studied. The effect of jets on flow characteristics such as separation and size/strength of the recirculation zones is studied using the FEM simulations. Lastly, the interaction between jet streams and grate streams as well as the interaction of opposing jets is studied using tracers to mark individual st...

[1]  M. Bercovier,et al.  A finite element for the numerical solution of viscous incompressible flows , 1979 .

[2]  B. Launder,et al.  The numerical computation of turbulent flows , 1990 .

[3]  R. Sani,et al.  On the time-dependent solution of the incompressible Navier-Stokes equations in two and three dimensions , 1980 .

[4]  T. Hughes,et al.  Streamline upwind/Petrov-Galerkin formulations for convection dominated flows with particular emphasis on the incompressible Navier-Stokes equations , 1990 .

[5]  D. Spalding.  A novel finite difference formulation for differential expressions involving both first and second derivatives , 1972 .

[6]  W. Zinser,et al.  Prediction of three-dimensional flows in utility boiler furnaces and comparison with experiments , 1988 .

[7]  M. Nallasamy,et al.  Turbulence models and their applications to the prediction of internal flows: a review , 1987 .

[8]  W. S. Lewellen,et al.  On the vorticity dynamics of a turbulent jet in a crossflow , 1986, Journal of Fluid Mechanics.

[9]  D. Spalding,et al.  A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows , 1972 .

[10]  I. Demirdzic,et al.  A calculation procedure for turbulent flow in complex geometries , 1987 .

[11]  Gilbert Strang,et al.  The application of quasi‐Newton methods in fluid mechanics , 1981 .

[12]  Ayodeji O. Demuren,et al.  False diffusion in three-dimensional flow calculations , 1985 .

[13]  L. Fuchs,et al.  On the accuracy of finite-difference and finite-element methods for the simulation of some incompressible flows , 1988 .