Experimental and Computational Aerodynamic Studies of Axially-Oriented Low-Fineness-Ratio Cylinders

For the successful completion of atmospheric entry, descent, and landing (EDL) missions, a body geometry must be selected which provides favorable dynamic aerodynamic properties. The types of experimental facilities capable of collecting information on these properties are limited; however, their numbers are growing thanks to the continued work by the aerodynamics community. NASA Langley Research Center (LaRC) is conducting dynamic aerodynamic testing using a subsonic magnetic suspension and balance system (MSBS), with the end goal of implementing a supersonic MSBS facility at NASA Glenn Research Center. MSBSs are also currently used at the Institute of Fluid Science (IFS) at Tohoku University in Japan for blunt body testing. With the MSBS community growing, there is an opportunity for collaboration in overlapping areas of interests, particularly in expanding general blunt body theory and estimating EDL vehicle performance using these modern facilities. The work encompassed in this thesis is a product of such a collaboration, with the specific subject of examination being an axially-oriented low-fineness-ratio cylinder. This geometry which has been previously tested at the IFS facility in Japan, was used as the basis for a multi-faceted campaign at the NASA LaRC MSBS, the Old Dominion University (ODU) low-speed wind tunnel, and computational fluid dynamic (CFD) simulations on the ODU high-performance computing cluster (HPC). Static tests were performed at the ODU wind tunnel on a 6′′ diameter model and were accompanied by static CFD simulations. Dynamic testing was performed at the NASA LaRC MSBS facilities on two 1.75′′ diameter models with varied gravitational centers and were accompanied by a dynamic CFD simulation. The experimental and computational goals were met, with results for static and dynamic aerodynamic forces as well as flow visualization being compared and contrasted. There was reasonable agreement between the static results with empirical data as well as the dynamic results. In particular, the agreements with empirical results for pitch angles from 0◦ to 90◦ stand as a significant validation to the scarce data that exists in this region