Computational Model for Electrode Erosion by High-Pressure Moving Arcs

The objective of this program is to mature and verify computational tools to predict electrode erosion by high pressure moving arcs at the High-Enthalpy Arc-Heated Facilities at Arnold Engineering Development Complex. Under an AFOSR Phase II STTR program, CFDRC developed a computational tool for simulations of electrode erosion by high-pressure magnetically moving arcs. The tool uses adaptive Cartesian mesh and multi-phase models to simulate gas flow in the arc attachment region, formation of cathode and anode spots, melting and vaporization of electrode surface, material removal due to vaporization, and magnetic forces. Experimental studies conducted during Phase II indicated crater formation associated with explosive electron emission at the cathode surface, and demonstrated possibility of arc root movement control over electrode surfaces by alternating magnetic fields. During this technology transition program, the tool will be further advanced, verified and validated to enable transition to production use. Advanced models for cathode and anode regions will be developed and implemented to improve code predictive capabilities. Test cases will be performed to demonstrate code abilities to numerically simulate electrode erosion in high-pressure magnetically moving arcs and provide parameters needed by various engineering codes. Software delivery, installation, training and user support will also be provided .