A predictive design capability is essential in optimizing the performance of energy devices to achieve high efficiency and low emissions. Such designs rely on a number of physical models, of which chemical kinetics plays a very critical role. The chemical kinetic mechanism of a fuel relies on a database of experimental values over a range of temperatures and pressures. These data include ignition delay time, fuel reactivity, elementary reaction rates, and species time-history profiles.
Shock tubes and Rapid Compression Machines (RCM) can provide well-defined temperatures and pressures for kinetics investigations that cover broad regimes of engineering and scientific interest. They can be used to achieve temperatures of 500-5000 K and pressures from sub-atmospheric to 500 atm. Chemical kinetics measurements performed behind reflected shock waves have near-instantaneous heating times, spatially uniform mixtures, and occur in near-stationary flows.
This lab focuses on the development of a wide range of sensors that employ tunable diode lasers, quantum cascade lasers, gas lasers, and dye lasers. These diagnostics are designed to measure temperature, pressure, velocity, flux, and a variety of chemical species.
Rapid Compression Machines are used to study auto-ignition of fuels for low temperature and high pressure conditions. Typical test times in an RCM are much longer than those in shock tubes and the conditions are highly controllable and repeatable.
A shock tube compresses (and heats) a fuel mixture almost instantaneously and is used to study the chemical kinetics of various fuels under homogeneous conditions of temperature and pressure.