Rate Coefficient Determinations for H + NO2 → OH + NO from High Pressure Flow Reactor Measurements.

Rate coefficients for the reaction H + NO2 → OH + NO (R1) have been determined over the nominal temperature and pressure ranges of 737-882 K and 10-20 atm, respectively, from measurements in two different flow reactor facilities: one laminar and one turbulent. Considering the existing database of experimental k1 measurements, the present conditions add measurements of k1 at previously unconsidered temperatures between ∼820-880 K, as well as at pressures that exceed existing measurements by over an order of magnitude. Experimental measurements of NOx-perturbed H2 oxidation have been interpreted by a quasi-steady state NOx plateau (QSSP) method.

Dehydration rate measurements for tertiary-butanol in a variable pressure flow reactor.

Fundamentally, the dehydration reaction of tertiary-butanol is frequently used as an internal standard for relative rate studies of other decomposition reactions. We report here a study using radical trappers to isolate this path in tertiary-butanol pyrolysis experiments conducted in the Princeton variable pressure flow reactor between 658 and 980 K. A novel technique that determines the rate constant value by applying a global least-squares fit incorporating all experimental species (tertiary-butanol, isobutene, and water) evolution data is developed and applied to yield six rate constant values at two reaction pressures (6.

Uncertainty analysis in the use of chemical thermometry: a case study with cyclohexene.

A general method to evaluate the absolute uncertainties in temperatures derived using chemical thermometry is developed and applied to the retro Diels-Alder reaction of cyclohexene. Experiments from previous studies of this reaction are reanalyzed to establish the minimum absolute uncertainty limit. Chemical thermometry results are compared with thermocouple measurements in experiments performed in a flow reactor at 6.

Functionalized graphene sheet colloids for enhanced fuel/propellant combustion.

We have compared the combustion of the monopropellant nitromethane with that of nitromethane containing colloidal particles of functionalized graphene sheets or metal hydroxides. The linear steady-state burning rates of the monopropellant and colloidal suspensions were determined at room temperature, under a range of pressures (3.35-14.

Composition of reaction intermediates for stoichiometric and fuel-rich dimethyl ether flames: flame-sampling mass spectrometry and modeling studies.

Molecular-beam synchrotron photoionization mass spectrometry and electron-ionization mass spectrometry are used for measurements of species mole fraction profiles for low-pressure premixed dimethyl ether (DME) flames with equivalence ratios ranging from near-stoichiometric conditions (Phi = 0.93) to fuel-rich flames near the limits of flat-flame stability (Phi = 1.86).

Computational singular perturbation analysis of two-stage ignition of large hydrocarbons.

Computational singular perturbation (CSP) analysis has been used to gain understanding of the complex kinetic behavior associated with two-stage ignition of large hydrocarbon molecules. To this end, available detailed and reduced chemical kinetics models commonly used in numerical simulations of n-heptane oxidation phenomena are directly analyzed to interpret the underlying fundamental steps leading to two-stage ignition. Unlike previous implementations of the CSP methodology, temperature is included as one of the state variables so that factors controlling ignition can be unambiguously determined.

High temperature 180 degrees laser-induced fluorescence probe for remote trace radical concentration measurements.

The design and validation are described of an optical probe for measurements of parts per million OH concentrations in actual combustion environments (1100 K, 1 atm).

Application of a two-component LDV to the measurement of flows induced by flames propagating over condensed fuels.

In the early stages of a fire, the two mechanisms by which heat transfer occurs are conduction and convection ahead of the flame through gas and fuel phases. The convective flows induced are characterized by low-fluid velocities with changes in magnitude and direction occurring over small distances accompanied by sharp temperature changes. These characteristics make quantitative measurements of fluid velocities difficult using conventional techniques.