The READY program: Building a global potential energy surface and reactive dynamic simulations for the hydrogen combustion

Abstract

READY (REActive DYnamics) is a program for studying reactive dynamic systems using a global potential energy surface (PES) built from previously existing PESs corresponding to each of the most important elementary reactions present in the system. We present an application to the combustion dynamics of a mixture of hydrogen and oxygen using accurate PESs for all the systems involving up to four oxygen and hydrogen atoms. Results at the temperature of 4000 K and pressure of 2 atm are presented and compared with model based on rate constants. Drawbacks and advantages of this approach are discussed and future directions of research are pointed out.

Quasiclassical Study of a Termolecular Reaction: A More Detailed Description of the Ho2 Collisional Stabilization Process

“…The modifications carried out on the Multiprocess Reaction Dynamics (MReaDy) program [6][7][8] to study the evolution of the formed HO * 2 radicals and follow their history in the bulk mixture is described in detail in our earlier work on this system [9]. In the following, we present a brief description.…”

“…With the aim of better understanding the HO * 2 stabilization process, our group recently adapted MReaDy, a Multiprocess Reaction Dynamics program [6][7][8], to study the evolution of the HO 2 radicals formed by collisions of H atoms with O 2 molecules [9] and following the history of these radicals in the bulk mixture. In addition to the stabilization procedure from Eq.…”

N‐dimensional switch function for energy conservation in multiprocess reaction dynamics

“…Figure 1 displays on the right side, the same H 2 /HO collision after implementing the function F n , using r in 5 0.25 nm and r out 5 0.35 nm. These values of r in and r out have been chosen because the transition distance used in our earlier work [1] was 0.30 nm, coinciding with the van der Waals region. In further studies, this transition region may be adapted according to the different types of molecules involved in the collision.…”

“…In order to allow the study of more complex systems, the function has been implemented for all channels occurring in all possible collisions, described in our earlier work. [1] We tested the overall effect of introducing the F n function carrying out a set of calculations for a hydrogen combustion system at initial temperatures of 1000 K, 2000 K, 3000 K, and 4000 K. We defined as initial conditions a cubic box of 20 nm length, containing 100 O 2 molecules, 100 H 2 molecules, and 5 hydrogen atoms, with initial translational, rotational, and vibrational energy distribution randomized according to the respective initial temperatures, and used the above referred values for r in 5 0.25 nm and r out 5 0.35 nm to define the inner and outer boundary regions.…”

“…The MReaDy program, recently presented, [1] builds a global Potential Energy Surface (gPES), defined by integrating diverse PESs, each one of them representing an elementary reaction that is expected to play a role in the chemical process. MReaDy was created having in mind the study of complex chemical processes such as the hydrogen combustion.…”