Application of scalar Monte Carlo probability density function method for turbulent spray flames

The objective of the present work is twofold: (I) extend the coupled Monte Carlo probability density function (PDF)/computational fluid dynamics (CFD) computations to the modeling of turbulent spray flames, and (2) extend the PDF/SPRAY/CFD module to parallel computing in order to facilitate large-scale combustor computations. In this approach, the mean gas phase velocity and turbulence fields are determined from a standard turbulence model, the joint composition of species and enthalpy from the solution of a modeled PDF transport equation, and a Lagrangian-based dilute spray model is used for the liquid-phase representation. The PDF transport equation is solved by a Monte Carlo method, and the mean gas phase velocity and turbulence fields together with the liquid phase equations are solved by existing state-of-the-art numerical representations. The application of the method to both open as well as confined axisymmetric swirl-stabilized spray flames shows good agreement with the measured data. Preliminary estimates indicate that it is well within reach of today's modern parallel computer to do a realistic gas turbine combustor simulation within a reasonable turnaround time. The article provides complete details of the overall algorithm, parallelization, and other numerical issues related to coupling between the three solvers.