High-Fidelity Simulation of Dynamic Weakly Ionized Plasma Phenomena

A computational and experimental research program is proposed to develop and validate a high-fidelity 3D non-equilibrium magnetohydrodynamic (MHD) plasma compressible flow code for advanced aerospace applications. The code will incorporate a physics-based kinetic model of air plasma with non-equilibrium conductivity sustained by an externally applied electric field. The model will include electron and ion motion in externally applied electric and magnetic fields, a non-equilibrium plasma chemistry and energy relaxation mechanism, as well as a mechanism for coupling the plasma with the flow via body force (Coulomb and Lorentz) interaction and purely thermal (i.e., localized heating) interaction. Feasibility studies will be carried out in Phase I, with rigorous validation of the software using results from recent low-temperature MHD flow control experiments. Proposed rotational Coherent anti-Stokes Raman scattering spectroscopy (CARS) measurements of temperature rise produced by Joule heating in a repetitive nanosecond pulse discharge will be used for further validation of the kinetic models and the code. A comprehensive development, implementation, and validation of the complete software tool will be carried in Phase II. The project leverages the expertise and extensive, first-of-its-kind relevant experimental experience at The Ohio State University, and the pioneering high-fidelity computational fluid dynamics (CFD)-based work at TTC Technologies. BENEFIT: The end product of the project will be a fast, well-validated, high-fidelity software module for accurate and robust modeling of dynamic weakly-ionized plasma phenomena in the presence of induced and/or external magnetic field. The software will be available both as a standalone tool that will be delivered to the Air Force and as a module that will be plugged into, and validated in, TTC''s flagship commercial multidisciplinary software AEROFLO. Thus, the developed tool will be a marketable product which, in Phase III, will be fully transitioned to the Air Force Research Laboratory (AFRL), government, commercial air frame companies, and third-party software companies. Most industries using CFD do not have the capability for modeling dynamic weakly-ionized plasma phenomena in the manner detailed in this proposal. Therefore, TTC''s new product line will be quite marketable, as companies will find it cheaper to plug it into their own CFD software packages, rather than developing the capability from scratch. The more accurate predictions from the resulting code will also bring more consulting business to TTC. Both government and non-government concerns will find the proposed software to be very valuable. The Department of Defense (DOD) and the National Aeronautics and Space Administration (NASA) will need the tool in their various research and design efforts on advanced hypersonic vehicles and missile defense technologies. The ability of the proposed software to accurately and efficiently simulate plasma flow control will prove to be very useful for drag and noise control in hypersonic vehicles. The proposed tool will also be invaluable in its ability to predict the occurrence of communication blackout, which results from the attenuation and/or reflection of radio waves by a plasma layer formed around a vehicle during a hypersonic or re-entry flight. The consequences of radio blackout in re-entry and hypersonic flight, which include the loss of communication, GPS navigation, mission command, and electric countermeasure capability, can be mitigated by predictive analysis with the proposed high-fidelity tool. The speedup from the CFD simulation and the ability to execute multi-processors, to take advantage of massive parallelization, will enable parametric testing of many design configurations on a timely basis. The proposed innovative module will make the product directly applicable to DARPA-funded initiatives on new aircraft designs. The expected accuracy and robustness of the procedure also assure the design data generated with the code. The ultimate benefits are high efficiency and stable systems. This will lead to significant savings in analysis time and money.