摘要: Laminar flame speeds at high pressure are difficult to experimentally observe. Typically, high-pressure flame diagnostic is accomplished through observation of a spherically expanding flame in a constant volume chamber. However, f... 展开 Laminar flame speeds at high pressure are difficult to experimentally observe. Typically, high-pressure flame diagnostic is accomplished through observation of a spherically expanding flame in a constant volume chamber. However, flame instabilities at large radius and ignition effects at small radius limit measurable pressure range for Laminar flame speeds. Advanced combustion devices which operate at high pressures to improve capabilities and efficiencies require high quality laminar flame speed to aid in simulations and development. To expand the measurable range of flame data for high pressure flame measurement, this study proposes the further investigation of the ignition source and the incorporation of ignition diagnostics into the traditional flame speed analysis. To achieve this goal in future research, experimental spark propagation is observed and described in detail with the goal of improved experimental control and understanding. Parameters such as pressure, composition, electrode geometry and surface quality are discussed and the implication it has on the observed schlieren kernel propagation. Careful preparation of the ignition source can lead to improved surface and shape for future flame measurements. It is also shown that the thermal energy dissipated into the gas during discharge can be captured experimentally through measurement of the spark voltage, current and plasma sheath voltage drop. With the experimentally captured thermal energy, a simple energy balance can be used to describe the size of the observed ignition kernel for radius larger than 0.3 mm (following breakdown). The measurement of the thermal energy is described utilizing two experimental methods to find the discharge voltage of the nonequilibrium region at the boundary of the electrodes. 收起