Experimental Characterization of the VKI Longshot Mach 14 Contoured Nozzle

This paper presents the experimental characterization of the recently commissioned Mach~14 hypersonic nozzle of the Longshot gun tunnel. The Longshot facility of the von Karman Institute for Fluid Dynamics is a short-duration hypersonic wind tunnel, which is capable of reproducing the high Mach and Reynolds numbers experienced during most atmospheric re-entries. The free-stream flow conditions were measured at several stream-wise locations with a sting-supported arrangement of a pitot rake, a reference total pressure probe, a static pressure probe, a heat-flux probe, and an acoustic probe. The flow characteristics were inferred from the free-stream measurements using an elaborated rebuilding technique. The investigations cover the assessment of: flow uniformity in terms of Pitot pressure, tunnel noise level, core flow diameter, and useful test time