WITHDRAWN: Numerical Investigation of Solid Fuel Ramjet Combustion With Increasing Modeling Fidelity

Solid fuel ramjet (SFRJ) engines have the potential to boost range and performance in hypersonic vehicles; however, efficiency is limited by the lack of physical understanding in the complex combustion physics. To develop next generation systems, a mix of high-fidelity scale-resolved models and computationally efficient low-fidelity tooling is required to both probe the fundamental interaction of turbulence, chemistry, and solid fuel pyrolysis whilst providing fast-turnaround, accurate system-level performance. This work considers direct comparison between large-eddy simulations (LES), Reynolds-averaged Navier-Stokes (RANS), and detached-eddy simulations (DES) to assess the role of modeling fidelity on cost and physical accuracy. The role of turbulence closure is explored, along with the selection of chemical kinetics fidelity and boundary condition specification. Numerical results are compared with detailed experimental flame temperature and regression rate measurements to provide a quantitative baseline. Overall, improved accuracy was generally observed with increasing model fidelity, but lower-fidelity numerical modeling was key to enabling time-efficient parametric analysis.