Ignition of a Liquid-Fueled Scramjet Using a Pulse Detonation Ignitor

This seminar investigates the performance of an Ethylene-Oxygen based pulse detonation ignitor (PDI) use to ignite a mixture of liquid fuel (JP-8) and air in a cavity-based scramjet combustor. Two injection schemes and two global equivalence ratios (0.4 and 0.6) are comparatively studied. The experiment was conducted with inlet air stagnation temperatures ranging between 1000K and 1500K, while maintaining a constant stagnation pressure of 13 bar. The performance of the pulse detonation ignitor is compared to a conventional spark plug with an energy of 1 J per pulse. The measurements include high-speed CH* chemiluminescence and Schlieren images. These measurements are further employed to gain a fundamental understanding of the ignition process. The result shows that although flame-holding exists in some of the studied cases with liquid fuel only, the standard spark plug fails to ignite the mixture without ethylene piloting. However, the PDI ignites the liquid fuel without additional piloting. Furthermore, the PDI can lead to thermal choking, which is desirable for dual-mode scramjets.

The work is towards M.Sc. degree under the supervision of Associate Professor Dan Michaels, Aerospace Engineering, Technion – Israel Institute of Technology.