This project will investigate the use of a four-temperature concept for highly nonequilibrium hypersonic flows. The development of hypersonic space vehicles for future NASA missions involves knowledge of complex aerothermodynamic phenomena such as thermal and chemical nonequilibrium. Since it is extremely difficult to simulate the thermochemically complex flow field around vehicle models in a ground-based experimental facility, it is highly desirable to obtain accurate numerical computations of the flow field. To do so, it necessary to have a physically valid set of conservation equations in the flow regimes of interest. The objective of this project is to develop a basic set of governing equations and physical models based on the concept of four independent temperatures (translational, rotational, vibrational-electronic, and electron temperatures), for the highly nonequilibrium hypersonic flows around future space vehicles. A phenomenological approach will be taken to clarify the technical issues to be resolved and to examine possible engineering methods to attack the issues. This comprehensive analysis of expected thermochemical nonequilibrium phenomena proposed for Phase I will provide the basis for further development of the detailed physical models. Phase II will incorporate these models into the required set of basic governing equations.This work will establish the theoretical feasibility of phenomenological odels in the highly nonequilibrium hypersonic flow around future space ehicles and planetary probes. The governing equations and physical models btained may become the basis for future development of computational fluid dynamics codes that will be used in the design of proposed space vehicles and planetary probes.nonequilibrium, aerothermodynamics, hypersonic, aeroassist entry, space vehicle, planetary probesSTATUS: Phase I Only
