Plasma-enhanced mixing and flameholding in supersonic flow

Area of Science:

• Aerospace Engineering
• Plasma Physics
• Combustion Science

Background:

• Supersonic combustion requires efficient mixing and stable flames.
• Plasma-based techniques offer potential solutions for combustion enhancement.

Purpose of the Study:

• Investigate plasma-based mixing, ignition, and flameholding in a supersonic model combustor.
• Evaluate different plasma generation schemes for improved combustion performance.

Main Methods:

• Experimental study using a 600mm model combustor with supersonic airflow (Mach 2).
• Direct fuel injection through wall orifices.
• Near-surface quasi-DC electrical discharge (3-24 kW) and long submicrosecond discharge.
• Comparison of plasma generator placement and a novel combined mixing/ignition technique.

Main Results:

• A novel plasma discharge scheme along the fuel jet demonstrated a significant advantage in flameholding limits.
• High-power density plasma deposition induced gasdynamic instability, promoting air-fuel mixing.
• Parametric study of ignition and flame front dynamics was conducted.

Conclusions:

• Plasma-based techniques show significant potential for high-speed combustion applications.
• The studied methods can aid in scramjet engine cold start/restart and stable operation.
• Optimized plasma discharge configurations are key for enhanced supersonic combustion.