@article{zheng_ordon_scharton_kuznetsov_roberts_2008, title={A new acoustic model for valveless pulsejets and its application to optimization thrust}, volume={130}, ISSN={["0742-4795"]}, DOI={10.1115/1.2900730}, abstractNote={Due to its simplicity, the valveless pulsejet may be an ideal low cost propulsion system. In this paper, a new acoustic model is described, which can accurately predict the operating frequency of a valveless pulsejet. Experimental and computational methods were used to investigate how the inlet and exhaust area and the freestream velocity affect the overall performance of a 50 cm pulsejet. Pressure and temperature were measured at several axial locations for different fuel flow rates and different geometries. Computer simulations were performed for exactly the same geometries and fuel flow rates using a commercial CFD package (CFX) to develop further understanding of the factors that affect the performance of a valveless pulsejet. An acoustic model was developed to predict the frequency of these valveless pulsejets. The new model treats the valveless pulsejet engine as a combination of a Helmholtz resonator and a wave tube. This new model was shown to accurately predict geometries for maximum thrust. The model was further extended to account for the effect of freestream velocity. Evidence is provided that valveless pulsejet generates the highest thrust when the inherent inlet frequency matches the inherent exhaust frequency.}, number={4}, journal={JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME}, author={Zheng, F. and Ordon, R. L. and Scharton, T. D. and Kuznetsov, A. V. and Roberts, W. L.}, year={2008}, month={Jul} }
 @article{geng_kiker_ordon_kuznetsov_zeng_roberts_2007, title={Combined numerical and experimental investigation of a hobby-scale pulsejet}, volume={23}, ISSN={["1533-3876"]}, DOI={10.2514/1.18593}, abstractNote={The pulsejet, due to its simplicity, may be an ideal micro propulsion system, but has received very little attention since the mid 1950’s. Here, modern computational and experimental tools are used to investigate the operation of a hobby scale (50 cm overall length) pulsejet. Gas dynamics, acoustics and chemical kinetics are all involved and are studied to gain an understanding of the various physical phenomena affecting pulsejet operation, scaleability and efficiency. A Bailey Machining Service (BMS) hobby pulsejet is instrumented to obtain pressure, temperature, thrust, and frequency. CH * chemiluminescence is utilized to determine combustion time and high speed imaging of the reed valve operation is undertaken to determine the valve duty cycle. Laser Doppler Velocimetry (LDV) has been used to measure the instantaneous exhaust velocity in these unsteady combustion devices. Numerical simulations are performed utilizing CFX to model the 3-D compressible vicious flow in the pulsejet using the integrated Westbrook-Dryer single step combustion model. The turbulent flow and reaction rate are modeled with the ke model and the Eddy Dissipation Model (EDM), respectively. Simulation results provide physical insight into the pulsejet cycle; comparisons with experimental data obtained in this research are carried out. The traditional view of a pulsejet as a 1/4 wave tube operating on the Humphrey cycle is modified with to account for valve operation and finite chemical kinetics.}, number={1}, journal={JOURNAL OF PROPULSION AND POWER}, author={Geng, T. and Kiker, A., Jr. and Ordon, R. and Kuznetsov, A. V. and Zeng, T. F. and Roberts, W. L.}, year={2007}, pages={186–193} }