2023, 53(3): 561-591.
doi: 10.6052/1000-0992-22-051
Abstract:
High performance simulation of computational fluid dynamics (CFD) can be mutually verified with hypersonic flight tests and high enthalpy ground equipment experiments, and will play a more important role in the research of thermochemical non-equilibrium effects and the development of future hypersonic vehicles. The paper reviews the research progress of CFD method of thermochemical non-equilibrium flow at home and abroad, summarizes the current situation and development trend of related thermochemical models, numerical schemes and development of CFD software, and finally points out the problems that should be paid attention to in basic research, software development, simulation application in the future. (1) In terms of thermochemical models, the commonly used temperature models are not completely accurate. The multi-vibrational temperature model has development potential, but is limited in engineering applications. The state-state models are more accurate but its simulation technology is not yet mature. More accurate thermodynamic transport models, finite-rate chemical reaction models, vibration-dissociation coupling models and surface effect models are important physical models to improve the accuracy of thermochemical nonequilibrium simulation, which are worthy of in-depth study. (2) In terms of numerical methods, multi-physical field coupling simulation is a hot issue and trend in the CFD research of hypersonic thermochemical nonequilibrium flows, which raises higher requirements for the robustness and convergence for CFD methods, and is worthy of special attention and research. In addition, the commonly used numerical schemes need to be remodeled based on the characteristics of thermochemical nonequilibrium flows, and the computational reliability of RANS method in thermochemical nonequilibrium turbulence simulation still needs to be verified and confirmed. (3) In terms of numerical software, the numerical solver based on structured/unstructured hybrid grid is more suitable for the requirements of industrial applications. The future hypersonic numerical software should have stable and robust solver for multidisciplinary multi-physical field coupling solution, and can satisfy the simulation requirements of larger grid scale and large-size complex shapes. (4) The computational efficiency of thermochemical nonequilibrium flow simulation can be improved by comprehensively employing a variety of acceleration techniques. The computational stiffness is a common fundamental problem in the research of thermochemical nonequilibrium numerical simulation method, and the stiffness elimination method still needs further study and develop.
Gao Z X, Jiang C W, Li C X. Review of numerical simulation methods for hypersonic and high-enthalpy non-equilibrium flow. Advances in Mechanics, 2023, 53(3): 561-591. doi: 10.6052/1000-0992-22-051.