Development and suppression of instability in post-discharge channel

The subject of consideration is the dynamic of disturbed zone generated by filamentary short-pulse discharge in atmospheric air and in high-speed airflow. The plasma of electrical discharges in airflow is considered as a quite promising method for flow/flight control and combustion enhancement. Preliminary analysis has shown that the short-pulse repetitive transversal electric discharge is one of the most prospective solutions for the duct with a circular cross-section. On the other hand the properties of the filamentary plasma are not well studied under such specific conditions. The effect of fast turbulent expansion of the post-discharge channel in high-speed flow was observed experimentally. The mechanism of the phenomena was described theoretically for quiescent ambient conditions. Experimental and theoretical results presented in this work demonstrate that turbulent motion arising in the after-spark channel can essentially enhance the rate of multi-components mixing. The development and/or suppression of instability can be controlled effectively by the parameters of supplying. The effects found are supposed to be applied for high-speed combustion enhancement due to non-equilibrium excitation of air/fuel composition and mixing acceleration of non-premixed multi-components flow.