Modeling of non-equilibrium effects on a double wedge configuration in hypersonic flows

Numerical simulations are extensively used for the modeling of hypersonic flows characterized by thermal and chemical non-equilibrium phenomena. The accurate modeling of non-equilibrium effects relies on knowledge of reaction rate constants and relaxation parameters, often extrapolated outside their range of applicability. The objective of this thesis is the validation of the non-equilibrium models conventionally used by the scientific community. To this aim, the flow over a double wedge configuration is simulated for a nitrogen and air gas mixture at hypersonic conditions. The results are compared with experimental work performed at the University of Illinois by Austin and Swantek. The flow governing equations are discretized and solved using a parallel cell centered finite volume solver within COOLFluiD. The accuracy of the simulations is second order in space and first order in time. The convective fluxes are discretized using the AUSM+ scheme and the time is carried out using the fully implicit Backward Euler scheme. The numerical predictions obtained show significant extent of thermal non-equilibrium between vibrational and translational energy modes, whereas chemical non-equilibrium is present only in the air case, since nitrogen molecules do not significantly dissociate. Two different observables are used for the validation: wall heat-flux, and Schlieren experimental data. In general, the numerical predictions are in good agreement with the experimental results. Only minor differences are observed in the heat flux or the shock structure configuration in the air and nitrogen cases.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Aerospace Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Mallikarjun Vagishwari, Shrutakeerti

Contributors dc:contributor

• Panesi, Marco

• non-equilibrium
• double wedge
• Computational Fluid Dynamics (CFD)
• hypersonics

Statement dc:rights

• Copyright 2014 Shrutakeerti Mallikarjun Vagishwari

Handle dc:identifier

http://hdl.handle.net/2142/78581

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/78581