WSEAS Transactions on Fluid Mechanics
Print ISSN: 1790-5087, E-ISSN: 2224-347X
Volume 8, 2013
Chemical Non-Equilibrium Reentry Flows in Two-Dimensions – Part I
Authors: ,
Abstract: This work presents a numerical tool implemented to simulate inviscid and viscous flows employing the reactive gas formulation of thermal equilibrium and chemical non-equilibrium. The Euler and Navier-Stokes equations, employing a finite volume formulation, on the context of structured and unstructured spatial discretizations, are solved. The aerospace problem involving the hypersonic flow around a blunt body, in two-dimensions, is simulated. The reactive simulations will involve an air chemical model of five species: N, N2, NO, O and O2. Seventeen chemical reactions, involving dissociation and recombination, will be simulated by the proposed model. The algorithm employed to solve the reactive equations was the Van Leer, first- and second-order accurate ones. The second-order numerical scheme is obtained by a “MUSCL” (Monotone Upstream-centered Schemes for Conservation Laws) extrapolation process in the structured case. The algorithm is accelerated to the steady state solution using a spatially variable time step procedure, which has demonstrated effective gains in terms of convergence rate, as reported in Maciel. The results have demonstrated that the most correct aerodynamic coefficient of lift is obtained by the Van Leer first-order accurate scheme in the inviscid, structured, blunt body simulation. Moreover, the shock position is closer to the geometry as using the reactive formulation than the ideal gas formulation. It was verified in the inviscid and viscous cases.