Estimation of Uncertainties for a Model Validation Experiment in a Wind Tunnel

A high-quality model validation experiment was performed in the NASA Langley Research Center Unitary Plan Wind Tunnel to assess the predictive accuracy of computational-fluid-dynamics models for a blunt-body supersonic retropropulsion configuration at freestream Mach numbers from 2.4 to 4.6. Static and fluctuating surface pressure data were acquired on a 5-in.-diam (127-mm-diam) test article with a forebody composed of a spherically blunted, 70 deg half-angle cone and a cylindrical aft body. One unpowered configuration with a smooth outer mold line was tested as well as three powered, forward-firing nozzle configurations: a centerline nozzle, three nozzles equally spaced around the forebody, and a combination with all four nozzles. A key objective of the experiment was the determination of experimental uncertainties from a range of sources such as random measurement variation, flowfield nonuniformity, and model/instrumentation uncertainties. This paper discusses 1) the design of the experiment to best cap...

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