Pulsating Burners: Controlling Mechanisms and Performance. Final Report, January 1, 1987-June 30, 1990

摘要

The objective of the study was to increase the understanding of the physical processes which control the mixing and heat release processes in valved, natural gas fired, pulse combustors. The effects of combustor geometry and heat transfer upon the performance of the pulse combustor were investigated. The flow and flame spread in the pulse combustor were visualized using high speed shadowgraphy and radical imaging, respectively. In addition, the flow field has been quantified using laser Doppler velocimetry. The resulting data were used to explain the dependence of the pulse combustor's performance upon the timing of the entry of the reactants and the complex interaction between the fuel and air jets. Furthermore, the reasons for the existence of lean and rich limits of operation were determined. Under a separate task, the acoustic characteristics of the various parts which make up a pulse combustor were determined using an impedance tube technique. Finally, an analytical scheme was developed which allows the calculation of the admittance of entire sections of the pulse combustor from measured admittances of its component parts.