@article{26620,
  keywords = {Chemical Kinetics, Response Surface},
  author = {Shaheen R Tonse and Nigel W Moriarty and Michael Frenklach and Nancy J Brown},
  title = {Computational Economy Improvements in PRISM},
  abstract = {<p>The PRISM piecewise solution mapping procedure is applied to reactive flow simulations of<br />(9–species) H2+air combustion. PRISM takes the solution of the chemical kinetic ODE system<br />and parameterizes it with quadratic polynomials. To increase the accuracy, the parameterization<br />is done piecewise, by dividing the multi-dimensional chemical composition space into hypercubes<br />and constructing polynomials for each hypercube on demand. The polynomial coefficients are<br />stored for subsequent repeated reuse. Initial cost of polynomial construction is expensive, but<br />it recouped as the hypercube is reused, hence computational gain depends on the degree of<br />hypercube reuse. We present two methods that help us to identify hypercubes that will ultimately<br />have high reuse, this being accomplished before the expense of constructing polynomials has been<br />incurred. One method utilizes the rate of movement of the chemical trajectory to estimate the<br />number of steps the trajectory would make through the hypercube. The other method defers<br />polynomial construction until a preset threshold of reuse has been met; an empirical method<br />which, nevertheless, produces a substantial gain. The methods are tested on a 0-D chemical<br />mixture and reactive flow 1 and 2-D simulations of selected laminar and turbulent H2+air flames.<br />The computational performance of PRISM is improved by a factor of about 2 for both methods.</p>},
  year = {2003},
  journal = {International Journal of Chemical Kinetics},
  volume = {35},
  pages = {438-452},
  month = {05/2003},
}