Computational Analysis of Steady Hypersonic Flow Fields of NASA Benchmark Geometries Utilizing ANSYS Fluent
Date of Award
Master of Science (MS)
The Hypersonic International Flight Research Experimentation (HIFiRE) program explores and advances hypersonic aerospace systems by developing a multitude of test flight geometries and conducting experimental test flights to obtain data for use in validation of computational models and results. This study focuses on computational validation of heat flux, and calculation of static pressure profiles, skin friction coefficient profiles, and flow contours. The flow fields studied are for Mach number 7.18 and angles of attack (α) of 0° & 2°. These flow fields include many compressible flow features such as an expansion wave at the intersection of the cone and flat cylindrical section, an oblique shock wave at the cylinder and flare connection point, and a detached bow shock at the tip of the geometry. These flow features are present in the experimental test flight data as well as in ground test studies conducted in the CALSPAN–University of Buffalo Research Center’s LENS I facility along with computational results presented at the 2022 High-Fidelity CFD Workshop. Computations are performed using the Reynolds-Averaged Navier-Stokes (RANS) equations with one-equation Spalart-Allmaras (SA) turbulence model in ANSYS Fluent with suitable boundary conditions which give results for non-dimensionalized heat flux and static pressure profiles that closely match the computational results presented at the 2022 High-Fidelity CFD Workshop within 5% for α = 2°.
Hypersonic flow past the Blottner Sphere is another benchmark test case recently proposed for verification and validation of CFD codes in the High-Fidelity CFD Workshop organized in 2022 by NASA Langley Research Center in association with AIAA. Investigations into Blottner Sphere date back to the early 1960s and it has continued to be a problem of great interest in the field of high-speed computational and experimental fluid dynamics. This paper also focuses on the computation of steady laminar hypersonic flow past the Blottner Sphere using the three-dimensional compressible Navier-Stokes equations with suitable boundary conditions in ANSYS Fluent. Results are obtained for surface heating and pressure on the sphere at Mach 5.0 freestream. The simulation results correctly predict the separated bow shock upstream of the sphere along with the shock detachment distance from the stagnation point. The computed normalized pressure and heat flux on the surface are compared with the results obtained by 2022 High-Fidelity CFD Workshop participants.
Ramesh K. Agarwal
Swami Karunamoorthy, David Peters