The pulsejet engine has always attracted the attention of researchers in the field of air-breathing propulsion due to its simple structure, low weight, and inexpensive manufacturing process. In this study, a parametric optimization was performed on an augmentor installed at the exhaust of a pulsejet engine. To this end, a transient axisymmetric numerical simulation of a valved pulsejet engine under flight conditions was carried out using ANSYS Fluent. The k–ω SST turbulence model was employed to capture the flow behavior, and the combustion process was modeled as a volumetric energy source. A suitable downstream section of the engine was selected to accurately compute the net thrust using the momentum equation. Simulations were conducted over multiple consecutive cycles until the flow and performance parameters exhibited harmonic oscillations. The thrust was then time-averaged over the final three cycles. Subsequently, assuming a cylindrical augmentor and parameterizing its geometry, the effects of three key parameters including the augmentor’s distance from the engine exit, its diameter and its length, on the thrust augmentation were investigated. Finally, a detailed aerodynamic analysis of the engine, with and without the augmentor, was presented. The results demonstrated that the optimized augmentor, by entraining ambient air and enhancing the exhaust momentum, increased the net thrust by approximately 170% compared to the configuration without an augmentor.
Bogdanov V. Interaction of masses in the operating process of pulse jet engines as a means of increasing their thrust efficiency. Journal of Engineering Physics and Thermophysics. 2006; 79: 506-511.https://doi.org/10.1007/s10891-006-0128-8
Maqbool D., Cadou C.P. Acoustic analysis of valveless pulsejet engines. Journal of Propulsion and Power. 2017; 33: 62-70. https://doi.org/2514/1.B36078
Nazar Parvar A., Fathali M. Impact of the geometrical parameters of valveless pulsejet engine on the thrust. Aerospace Knowledge and Technology Journal. 2015; 3: 89-101 (In Persian).
Agarwal A., Pitso I. Modelling and numerical exploration of pulsejet engine using eddy dissipation combustion model. Materials Today: Proceedings. 2020; 27(2):1341-1349. https://doi.org/10.1016/j.matpr.2020.02.620
Peterson A.C. Combustion jet propulsion means. U.S. Patent 1,980,266. 1944.
Paxson, D., Litke, P., Schauer, F., Bradley, R., and Hoke, J. Performance assessment of a large scale pulsejet-driven ejector system. 44th AIAA Aerospace Sciences Meeting and Exhibit. Reno, Nevada, 2006. https://doi.org/10.2514/6.2006-1021.
Zheng, F., Kuznetsov, A. V., Roberts, W. L., and Paxson, D. E. Influence of Geometry on Starting Vortex and Ejector Performance. J. Fluids Eng. 2011; 133(5): 051204. https://doi.org/10.1115/1.4004082.
Subramanian, M., Venkatesh, N., Gopikannan, S., Harish, V., and Kavin, V. Estimation of mechanical properties of water augmented pulse jet engine. Int. J. of Adv. Res. 2020; 8: 747-755. https://dx.doi.org/10.21474/IJAR01/10689.
Sayres J.S. Computational fluid dynamics for pulsejets and pulsejet related technologies. M.S. thesis. North Carolina State University. 2011. Available from: http://www.lib.ncsu.edu/resolver/1840.16/6902
Paxson D., Wilson J., Dougherty K. Unsteady ejector performance: an experimental investigation using a pulsejet driver. 38th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. Indianapolis, 2002.
Fox R.W., McDonald A.T., Pritchard P.J. Introduction to fluid mechanics. Wiley online library, 10th Edition, 2020.
Hill P.G., Peterson C.R. Mechanics and thermodynamics of propulsion. 2nd Edition, Pearson, 1991.
Turns S.R. An introduction to combustion: concepts and applications, 3rd Edition, Mechanical Engineering Series, McGraw-Hill, 2011.
Mattingly J.D., and Boyer K.M. Elements of propulsion: gas turbines and rockets, 2nd Amer Inst of Aeronautics, 2016.
Riasatfard, Y. , Nili Ahmadabadi, M. and Ghadak, F. (2025). Parametric Study of the Thrust Augmentor of a Pulsejet Engine in a Low-Mach-Number Compressible Flow Regime Using Unsteady Numerical Simulation. Journal of Computational Methods in Engineering, 44(2), 189-224. doi: 10.47176/jcme.44.2.1064
MLA
Riasatfard, Y. , , Nili Ahmadabadi, M. , and Ghadak, F. . "Parametric Study of the Thrust Augmentor of a Pulsejet Engine in a Low-Mach-Number Compressible Flow Regime Using Unsteady Numerical Simulation", Journal of Computational Methods in Engineering, 44, 2, 2025, 189-224. doi: 10.47176/jcme.44.2.1064
HARVARD
Riasatfard, Y., Nili Ahmadabadi, M., Ghadak, F. (2025). 'Parametric Study of the Thrust Augmentor of a Pulsejet Engine in a Low-Mach-Number Compressible Flow Regime Using Unsteady Numerical Simulation', Journal of Computational Methods in Engineering, 44(2), pp. 189-224. doi: 10.47176/jcme.44.2.1064
CHICAGO
Y. Riasatfard , M. Nili Ahmadabadi and F. Ghadak, "Parametric Study of the Thrust Augmentor of a Pulsejet Engine in a Low-Mach-Number Compressible Flow Regime Using Unsteady Numerical Simulation," Journal of Computational Methods in Engineering, 44 2 (2025): 189-224, doi: 10.47176/jcme.44.2.1064
VANCOUVER
Riasatfard, Y., Nili Ahmadabadi, M., Ghadak, F. Parametric Study of the Thrust Augmentor of a Pulsejet Engine in a Low-Mach-Number Compressible Flow Regime Using Unsteady Numerical Simulation. Journal of Computational Methods in Engineering, 2025; 44(2): 189-224. doi: 10.47176/jcme.44.2.1064
)