16.3. Transient Solution Method

The system of ordinary differential equations described for the Reactor Models is generally stiff, which means that there is a large disparity in time scales for evolution of different species in the reactor system. Such systems are most efficiently solved by implicit techniques for time integration. For transient cases, a modified version of a software package called DASPK [123], [124] performs the time integration, as well as the first-order sensitivity analysis. We employ the direct-solution method in DASPK, which uses backwards-differencing methods for the time integration. Details of the DASPK solver are discussed by Li and Petzold.[123] The Reactor Models that employ the DASPK solver for time-accurate transient simulations are:

  1. Closed Homogeneous Reactor

  2. IC HCCI Engine

  3. Closed Plasma Reactor

  4. Perfectly Stirred Reactor (PSR)

  5. Plasma Reactor

  6. Plug-flow Reactor (PFR)

  7. Honeycomb Reactor

  8. Plasma Plug-flow Reactor (Plasma PFR)

  9. Closed Partially Stirred Reactor (Closed PaSR)

  10. Partially Stirred Reactor (PaSR)

  11. Stagnation Flow CVD Reactor

  12. Rotating Disk CVD Reactor

In the case of the PaSR models, several solver options are provided.