Development and application of numerical models for reactive flows

This report focused on developing mathematical and computational models which accurately and efficiently describe the behavior of complex physical systems such as: chemically reacting flows; transition from laminar to turbulent flow in reacting gas mixtures; laser-induced shock waves in an explosive medium; initiation, propagation, extinguishment, and structure of laminar flames. Work carried out in extending the flux-corrected transport (FCT) flow models to three dimensions and to generalize meshes is described. The extension to three dimensions required the development of surface definition software and sophisticated data structures to avoid excessive CPU-time overheads for the search operations involved. The hybrid method developed in combining the finite element method with the flux-corrected transport method (FEM-FCT) is useful for solving problems involving steady and unsteady transonic and supersonic flow in irregular geometries. The VOYEUR graphics system is described. It is used in conjunction with two instruments, namely a color hardcopy device (a Tektronix 4115 compatible printer/plotter, VOYEUR being implemented on a Tektronix 4115) or a DICOMED graphic output device. It is a menu driven system which builds up from a simple set-up to more complicated plots compiled from this initial information. Work carried out on transverse and axisymmetric jets, mixing enhancement in supersonic shear layers, unforced spatially-developing mixing layer and subgrid closures is described.