AN INVESTIGATION OF THE ACCURACY OF MANIFOLD METHODS AND SPLITTING SCHEMES IN THE COMPUTATIONAL IMPLEMENTATION OF COMBUSTION CHEMISTRY

This paper is concerned with the efficient computational implementatio n of combustion chemistry, for use in PDF methods and other applicatio ns. A new method of coupling reactions and mixing processes based on m anifold points with detailed chemistry is developed. Investigations ar e made of three different kinds of methods: the direct numerical integ ration of the coupled reaction and mixing equations; the direct numeri cal integration of the equations obtained by using operator-splitting to split reaction and mixing; and the new method - solving the split s ystem based on manifold points with detailed chemical kinetics. Errors between the solutions are studied. It is found that chemical reaction s have a significant influence on the accuracy of operator-splitting m ethods. The solution of the split systems based on manifold points pro vides an accurate representation for the solution of the full coupled equations. This means that tabulations can be made on manifolds with n o simplification made to the chemistry. (C) 1998 by The Combustion Ins titute.