73th Annual Meeting of the APS Division of Fluid Dynamics (November 22, 2020 — November 24, 2020)

V0025: Detonation Initiation and Exhaust of a Pulse Detonation Combustor

Authors

• Mohammad Rezay Haghdoost, Laboratory for Flow Instabilities and Dynamics, Technische Universität Berlin
• Daniel Edgington-Mitchell, Laboratory for Turbulence Research in Aerospace and Combustion, Monash University
• Sergio Bengoechea, Numerische Fluiddynamik and Experimentelle Strömungsmechanik, Technische Universität Berlin
• Bhavraj Thethy, Laboratory for Turbulence Research in Aerospace and Combustion, Monash University
• Farkhondeh Rouholahnejad, Laboratory for Flow Instabilities and Dynamics, Technische Universität Berlin
• Fabian Habicht, Chair of Fluid Dynamics, Technische Universität Berlin
• Christian Oliver Paschereit, Chair of Fluid Dynamics, Technische Universität Berlin
• Julius Reiss, Numerische Fluiddynamik and Experimentelle Strömungsmechanik, Technische Universität Berlin
• Kilian Oberleithner, Laboratory for Flow Instabilities and Dynamics, Technische Universität Berlin

DOI: https://doi.org/10.1103/APS.DFD.2020.GFM.V0025

The pulse detonation engine (PDE) has the potential to drastically increase the efficiency of conventional gas turbines, which currently contain isobaric combustors. In a hybrid-PDE configuration, these combustors are replaced by an annular array of pulse detonation combustors (PDCs). Each PDC consists of a pipe containing a convergent-divergent nozzle that is filled with a stoichiometric mixture of hydrogen and air. Ignition of the mixture results in an accelerating deflagration (subsonic combustion wave), forming a leading shock wave that focuses at the convergent-divergent nozzle to produce a detonation (supersonic combustion wave). This process is demonstrated using a 2D numerical simulation and reveals the essential aspects of the detonation transition. The detonation travels through the PDC detonation tube before exhausting out of the open end and producing a transient supersonic jet. This transient exhaust flow is visualized using the schlieren technique, highlighting the changes in the density gradient. By altering the PDC's operating conditions, the underlying fluid dynamic process of the transient supersonic jet is visualized in great detail. Alongside the scientific insights, the visualizations show the complexity and beauty associated with the dynamic evolution of a transient supersonic jet.