Development of 3-D Computer Code to Study Autoignition in a Turbulent Medium

Abstract

In. this paper, the development and validation of 3-dimensional computer code to analyze autoignition in a non-premixed medium under isotropic and homogeneous turbulence is presented. During autoignition the density changes are considerable and hence the constant density assumption cannot be made. To incLude the effects of density, fluctuations caused due to spatial inhomogeneities in temperature and species, a pressure based method is deveLoped herein, which is a spectral impLementation of the sequential steps followed in the predictor-corrector type of algorithms. The velocity and pressure field are solved in spectral space while the scalars are solved in physical space. The combustion is assumed to take pLace through a single-step irreversible reaction. Simulations are first validated for nonreacting turbulence without any scalars. Next, the decay, of scalar variance has been studied which showed a power law decay as observed by the earLier researchers. Then. the program is extended to analyze the reacting flow problems. The code has been parallelized using MPI calls to run it efficiently on IBM-SP machines. The details of the governing equations, solution methodology and comparison of present results with previous data are presented.