Combustor flow computations in general coordinates with a multigrid method

A computational approach has been developed and applied to calculate the single phase combusting turbulent flowfields. The approach attempts to strike a reasonable balance to handle two competing aspects of the modeling work, namely, the complicated physical and chemical interactions of the flow, and the requirements in resolving the three-dimensional geometrical constraints of the combustor contours, film cooling slots, and circular dilution holes. The algorithm employs the non-orthogonal curvilinear coordinates, the second-order accurate discretizations, a multigrid iterative solution procedure, the standard k-E turbulence model, and a combustion model comprising of an assumed probability density function and the conserved scalar variable formulation. This paper gives an account of the overall computational approach, including recent advances in the solution procedure of the coupled pressure and velocity variables, the 3-D grid generation algorithm, 2-D adaptive grid method applied to recirculating turbulent reacting flows, and theory/data assessments for 3-D combusting flows in a modern annular gas-turbine combustor. Such a numerical approach can be useful in aiding combustor design.