| This work is concerned with two major aspects of pulse detonation engines (PDE) research: modeling and laser-based sensing. The modeling addresses both ideal and real considerations relevant to PDE design. First, an ideal nozzle model is developed which provides a tool for choosing area ratios for fixed-geometry converging, diverging, or converging-diverging nozzles. Next, losses associated with finite-rate chemistry are investigated. It was found that PDEs can experience up to 10% reduction in specific impulse from this effect if 02 is used as the oxidizer, whereas the losses are negligible for air-breathing applications. Next, heat transfer and friction losses were investigated and found to be greater than the losses from simple straight-tube PDEs. These losses are most pronounced (∼15%) when converging nozzles are used.;The second portion of this work focuses on laser-based absorption sensing for PDEs. The mid-infrared was chosen as the best way to address the challenges of signal-to-noise ratio, sensitivity, robustness, and sensor bandwidth. A water vapor sensor was developed and applied to the PDE at the Naval Postgraduate School. This sensor provided improvements in temperature accuracy, and it revealed that water (generated by the vitiator) inhibited performance of the engine. Next, a JP-10 absorption sensor was developed and applied to the same engine. This sensor provided thermometry data at a higher temporal resolution than the water sensor. The sensor also provided crucial information on equivalence ratio and fuel arrival time which enabled the engine to be successfully operated on JP-10 and air for the first time. |
