Air-activated chemical warming devices use an exothermic chemical reaction of rapidly oxidizing iron to generate heat for therapeutic purposes. Placing these products in a hyperbaric oxygen environment greatly increases the supply of oxidant and thus increases the rate of reaction and maximum temperature. Testing for auto-ignition and maximum temperatures attained by ThermaCare Heat Wraps, Play...

Abundant availability and potential for lower CO2 emissions are drivers for increased utilization of natural gas in automotive engines for transportation applications. However scarce refueling resources for on-road vehicles impose an infrastructure limited barrier on natural gas use in transportation. A novel ‘bimodal’ engine which can operate in a compressor mode has been developed that allows...

We report a large-eddy simulation (LES)/probability density function (PDF) modeling study of a turbulent lifted ethylene jet flame in a heated air coflow, using a 22-species reduced chemical mechanism. In this flame, the central ethylene jet is ignited by the heated coflow, and the lifted jet flame base stabilization reaches a statistically stationary state. In this LES/PDF study, the filtered ...

One technology that seems to be promising for automobile pollution reduction is the Homogeneous Charge Compression Ignition. This technology still faces auto-ignition and emission control problems. This paper focuses on the emission problem, since it is incumbent to realize engines that pollute less. For this purpose, this paper presents results concerning the measurement of the emissions of CO...

In this study we summarize and analyze experimental observations of cyclic variability in homogeneous charge compression ignition (HCCI) combustion in a single-cylinder gasoline engine. The engine was configured with negative valve overlap (NVO) to trap residual gases from prior cycles and thus enable auto-ignition in successive cycles. Correlations were developed between different fuel injecti...

It is very well known that the efficiency of an SI engine is limited by knock occurrence. As a compromise between knocking combustion avoidance and an accepted level of efficiency, an engine is typically operated at very close to the knocking boundary. However, the position of an engine knocking boundary is shifted if the fuel composition changes. The description of this abnormal combustion is ...

Conventional gasoline engines suffer from low performance and NOx emissions. Controlled auto-ignition (CAI), sometimes referred to as homogeneous charge compression ignition (HCCI), is a promising concept solve such problems. CAI has the potential improve spark (SI) engine fuel economy while at same time solving trade-off of NOx-soot emissions found in (CI) engines. The can reach comparable tha...

The stabilisation of a lifted flame issuing in a vitiated co-flow has been studied both experimentally and numerically with the objective of resolving whether the dominant mechanism is due to auto-ignition or to premixed flame propagation. A key parameter used in both studies is the lift-off height, LH defined at the first location of occurrence of heat release downstream of jet exit plane. Exp...