Michael R. Zachariah, Principal Investigator

High-Temperature Chemistry and Physics of Vapor Phase Nanoparticle Growth and Microcombustion Processes

These researchers worked in the area of high temperature chemistry and physics of vapor phase nanoparticle growth and microcombustion processes. Their studies were aimed at using molecular-based computation to understand the growth of nanoparticles formed from the vapor and the high temperature oxidation of hydrocarbons in microcombustors. The application sought the formation of new materials and the control of the emission of toxic heavy metal particles from combustors. The studies employed two theoretical approaches:

• Classical Molecular Dynamics (MD) simulations to understand particle-particle interactions and properties; specifically, these studies are aimed at determining particle- particle reactivity and physical/chemical properties of small particles (surface tension, internal pressure, etc.); in addition, faster algorithms for accelerating the MD computations were developed
• The chemkin suite of programs used in the simulation of combustion and chemical vapor deposition processes

Ab initio molecular orbital methods were used to construct thermochemical databases and reaction rate data for the construction and testing of reaction mechanisms for reacting flows; the primary tool employed was the guassian suite of programs. The results from the MD and ab initio computations were used to feed reacting flow simulation programs aimed at simulating particle forming flows.

In one project, simulated nanoparticle formation was driven by chemical nucleation processes by incorporating aerosol dynamics models into the chemkin software. In other studies, the group developed a MicroElectrical Mechanical Systems (MEMS)-based microcombustor model for a free-piston micro-engine. These studies were performed with the intention of simulating the combustion on the microscale with detailed chemistry (several thousand chemical reactions).

Research Group

Hans Aichlmayr, Graduate Student Researcher
Federico Galli, Research Associate
Takumi Hawa, Research Associate
Soo Hjung Kim, Graduate Student Researcher
Ravi Kumar, Graduate Student Researcher
Kari Lehtinen, Visiting Researcher
Dibyendu Mukherjee, Graduate Student Researcher
Prahalad Parthangal, Graduate Student Researcher
Irina Schweigert, Visiting Researcher
Song-Moon Suh, Graduate Student Researcher