Development of Validated Hypersonic Plasma Kinetics Models Inclu
Abstract
Hypersonic systems are under active development by several organizations within the DoD including the Navy, AF, Army, DARPA, and MDA,. These vehicles operate over a wide variety of hypersonic Mach numbers from 5 to 25. At speeds above Mach 10, the temperatures in h,ypersonic flows can be high enough to generate pla, radio communications, trails behind a vehicle for long distances potentially allowing for detection and plasma may enable reduced h,eating and/or drag using applied electromagnetic fields.At the hypersonic conditions of interest to DoD, the most likely chemical pa,thway to initiate plasma formation is through molecular dissociation, Zeldovich exchange reactions, and finally associative ionizati,on (AI) that forms molecular ions. Recent work indicates for the first time that the AI formation of ions in air primarily proceeds,through excited states of atoms such as nitrogen and oxygen. The proposed work is therefore based on the premise that it is necessar,y to resolve low lying atomic electronic states to accurately model plasma generation under hypersonic conditions. Hence, to accurat,ely model AI reactions it is also necessary to have a detailed understanding of collision induced excitation (CIE) processes which g,enerate electronically excited atoms through interactions with heavy particles (HP-CIE) and electrons (E-CIE).There are several key,gaps in the current understanding of these processes: (1) Most of the current models for the dissociation and Zeldovich reactions ar,e not validated; (2) None of the relevant HP-CIE rates have been measured at hypersonic temperatures; and (3) The AI model and rates, currently used in the hypersonics community do not account for atomic excitation and have not been validated for sub-orbital hypers,onic conditions. To address these significant technical gaps, we have developed three major objectives for the proposed research: (1,) Address the absence of HP-CIE rates for temperatures relevant to hypersonic flows through detailed experimental and computational,studies; (2) Generate and validate AI rates resolved by atomic excitation state for hypersonic flow conditions through detailed expe,rimental and computational studies; and (3) Evaluate existing models for dissociation, Zeldovich and E-CIE processes using the exper,imental facilities and computational tools developed and applied throughout the project.The research objectives will be achieved by,a closely coordinated team that comprises experimental and computational capabilities across the full range of scales from individua,l collisions to hypersonic flows. Each investigator is a world leader in their field and brings a unique set of technical capabiliti,es and prior experience of relevant and productive research. Most importantly, in combination, these individuals and their research,capabilities will generate data and information whose total value is significantly enhanced beyond what they could produce working s,eparately.The innovative team synergy involves information flow all across the project. For example, sensitivity analysis will be co,nducted of hypersonic flow experiments to identify the key HP-CIE and AI interactions. The results will inform the prioritization of, the molecular-level studies in which the computed rates will be validated by the molecular beam experiments and then used in the an,alyses of simple reacting systems. Shock tube experiments will provide data to validate the detailed plasma generation kinetic mecha,ws in a shock tunnel.Successful completion of the proposed research will significantly improve the accurate prediction of hypersonic
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 07, 2022
- Source ID
- N000142212661
Entities
People
- Iain D. Boyd
Organizations
- Office of Naval Research
- Regents of the University of Colorado
- United States Navy