Trajectory, Development, and Temperature of Spark Kernels Exiting into Quiescent Air (Preprint)

An inverse deconvolution technique was developed to determine the temperature and sensible energy of the kernels. This technique is evaluated by a sensitivity analysis and comparisons to measurements on a well characterized flame. Infrared images show that the kernels develop into a toroidal shape after exiting from the igniter. The statistical distribution of the trajectory of spark kernels is symmetric. Buoyancy forces have a negligible effect on the trajectory. Regions of high and low radiation intensity are observed in the kernels, indicating temperature gradients within the gases. The radiation intensity emitted by spark kernels decreases by more than an order of magnitude after exiting the igniter. Average temperature values decrease by less than 30 over 2 cm of the spark trajectory. Over that distance the sensible energy of the kernel decreases by 80.