APPLICATIONS OF DIRECT NUMERICAL-SIMULATION TO PREMIXED TURBULENT COMBUSTION

This paper describes recent progress in the field of Direct Numerical Simulations (DNS) for premixed turbulent combustion. A classification of Computational Fluid Dynamics techniques used in reacting flows is f irst proposed. Numerical methods and problems specific to DNS of combu stion like grid resolution or boundary conditions treatment are discus sed. The presentation of DNS results is done in the framework of flame let modeling. The domain of validity of the flamelet assumptions is st udied with simulations of flame vortex interactions. The local structu re of flamelets in premixed turbulent combustion is investigated using two and three-dimensional DNS with simple chemistry models. Effects o f complex chemistry are considered through recent two-dimensional DNS performed with realistic chemical schemes. Flame surface densities, fl ame strain and curvature statistics obtained from various three dimens ional simulations are given and implications for modeling are presente d. DNS is also exploited to deal with some specific problems like turb ulent flame ignition or flame-wall interactions. This review is conclu ded with a discussion of current limitations and a list of future chal lenges. Copyright (C) 1996 Elsevier Science Ltd.