Acoustic Analysis of Valveless Pulsejet Engines

An acoustic method for analyzing the operation of valveless pulsejets is developed using a fluid–electrical analogy and transmission line theory. The analysis technique assumes that a valveless pulsejet is an acoustic duct with area and temperature varying along its length. The area and temperature are used as inputs to the calculation, and the outputs include operational frequency and axial pressure distributions in both space and time. Operating frequencies are predicted to within 6% of the experimental values for five different pulsejet configurations. The present analysis method is also compared to existing models in the literature, and the reasons for the successes and failures of previous approaches are explored.