OCR Text |
Show - 2 - growth in the ability to simulate the detailed chemical kinetic processes which control the rate of combustion and heat release, as well as the formation rates of various chemical pollutants such as nitric oxide. In addition to aiding in the interpretation of existing laboratory data, a modeling approach can also be helpful by suggesting further experimental efforts which may be particularly productive. The emphasis of the present study is on the combustion of methane and natural gas. Current experimental basic research on pulse combustion at Battelle-Columbus Laboratories and at Georgia Institute of Technology, both supported by the Gas Research Institute, and at Sandia National Laboratories supported by the U.S. Department of Energy, is concerned primarily with methane and natural gas combustion. In addition, the dominant practical application area for pulse combustion at present is for natural gas-burning furnaces. The principles outlined below are sufficiently general to apply to other fuel-oxidizer mixtures, and examples of propane-air mixtures are discussed, but most of the work described concerns the oxidation of methane and natural gas. NUMERICAL MODEL AND CHEMICAL KINETICS MECHANISMS The numerical model employed for the calculations described in this paper is the HCT code [1] developed at LLNL. This program solves the coupled differential equations of conservation of mass, momentum, energy, and each chemical species, using finite difference techniques. Since the typical pulse combustor is an open system in which products are driven out |