부산대학교 도서관

This paper describes control experiments in liquid metal combustion. Preliminary results are reported for the effectiveness of open-loop control techniques in improving closed-cycle liquid metal combustion. The effects of non-axisymmetric nozzle shapes and pulsed oxidant flow rate on the combustion process are tested by measuring the total fuel utilization at the point of end-of-run pressurization, which is characteristic of this type of combustor, and by observing the jet/bath dynamics using X-radiography. Nozzle geometry and oxidant flow rate are the parameters used to control the combustion process. The reacting jet stability and rate of end-of-run pressurization is affected somewhat by the nozzle geometry however, no significant effect is observed on the total fuel utilization achieved. Pulsed oxidant injection produces an expected large effect in bath/jet dynamics as the oxidant flow rate is pulsed from 3 to 20 gr/sec, but no statistically significant change in total utilization is demonstrated. The causes of combustion chamber pressurization during the combustion process and at end-of-run are discussed. In an effort to explain significant pressurization of the combustion chamber developed during the combustion process, chamber pressure dependence on oxidant purity grade, oxidant flow rate and hydrogen content are reported. The presence of relatively small amounts of hydrocarbons introduced during combustor fabrication produces significant pressurization of the combustion chamber throughout the combustion period, while the chamber pressure has relatively little dependence on the oxidant mass flow rate or oxidant purity. No significant effect of pressurization caused by hydrocarbons on maximum fuel utilization is observed.