Plasma-Assisted Ignition in the Flow-Through Combustion Chamber

The work is aimed to the problem of the organization of combustion in a high-speed flow of a fuel mixture using subcritical streamer microwave discharges. The problem is relevant for engines using combustion at a constant volume, in high-speed subsonic and supersonic flow of the fuel mixture, as well as in detonation engines with forced ignition. The goal is to investigate the possibility of igniting of a series of attached subcritical microwave discharges located at some distance from each other in a high-speed stream near metal or dielectric screen, and also to investigate the ability of these discharges to ignite a fuel mixture. This goal is achieved by the fact that numerical calculations of microwave discharges near the screen are performed at a flow velocity of 5 m / s to 500 m / s. Then, the calculations are repeated for the fuel mixture with a fuel excess ratio eta from 0.55 to 1.5. The results of calculations of a mixture of propane with air are compared with experiments that were carried out on an apparatus with a wavelength of lambda = 12.3 cm with a microwave beam power of P = 1 kW and a microwave pulse duration of tau = 0.2 sec. The significant result is that the deeply critical discharge connected to the resonator on the dielectric screen is not blown away by the high-speed flow and ignites the mixture. Importance - a microwave discharges ignite fuel over the entire speed range. The calculation results are confirmed by experiment.