Validation of the Density Based Navier-Stokes solver simulating the combustion process of different Scramjets combustors

Validation of the Density-Based Navier-Stokes solver simulating the combustion process of different scramjet combustors Bruce Crawford Ansys Inc., 2600 Ansys Dr, Canonsburg, PA 15317 USA Jayson Small , Liwei Zhang Aerodynamics Research Center, The University of Texas at Arlington, Arlington, TX 76019, USA Valerio Viti , Shaoping Li Ansys Inc., 10 Cavendish Court, Lebanon NH, 03766, USA Jean-Sebastien Cagnone Ansys Canada Ltd., 1000 Sherbrooke Street West, Montreal QC, H3A 3G4 Canada With the recent rise in interest in new hypersonic propulsion systems, there has been a push to expand Ansys Fluent CFD high-speed Density-Based Navier-Stokes (DBNS) solver capabilities to model these complex systems. The goal of the improvement is to be able to simulate the combustion process inside scramjet engines with a high level of accuracy and in a streamlined and efficient way . High-fidelity numerical simulations can provide invaluable insights on the high-speed flow mixing and combustion processes of scramjet motors as well as detailed temperature and heat flux distribution through the vehicle propulsion system. In order to achieve the desired fidelity, these numerical simulations need to include physical models that can predict phenomena such as compressibility, turbulence, and chemical non-equilibrium. Several new and enhanced chemical non-equilibrium and turbulence-combustion interaction models have been introduced to meet the need for improved accuracy by the community. The current work presents three validation studies of scramjet combustion cases. The three cases selected are representative of different combustor configurations and fuels and they are: the Burrows-Kurkov combustor, the DLR supersonic combustor, and the NASA HIFiRE 2 Scramjet combustor. Each of the three geometries is meshed using Ansys meshing tools, creating 2D, 3D hexahedral, and 3D Fluent Poly-Hexcore Mosaic meshes. Four combustion models available in Ansys Fluent CFD high-speed solver are validated for each of the validation studies. Three of these combustion models considered are typically used for laminar chemistry solution, nominally the React to Equilibrium (RTE), Direct source method (DSM), and Stiff Chemistry (ODE) solvers. The fourth combustion model is typically used for cases with turbulence/combustion interaction (TCI), and that is the Eddy Dissipation Concept (EDC) PaSR model. All validation cases presented use the K-Omega SST turbulence model to simulate the flow turbulence.