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Uncertainty Analysis of Slug Calorimeters in the HyMETS Arc-Jet FacilityThe objective of this work is to perform an uncertainty analysis of the deduced stagnation heat flux environment on a slug calorimeter for conditions that span the performance envelope of the Hypersonic Materials Environmental Test System arc-jet facility located at NASA Langley Research Center. Analytical solutions are developed for boundary-value problems on the slug element accounting for non-ideal effects, including spatial variation in the slug heat flux, multi-dimensional thermal conduction, and back-face losses, which departs from the state-of-the-art method derived from the American Society of Testing and Materials. Boundary-value problem definitions are informed by preliminary finite element thermal analysis of the slug calorimeter assembly (including both slug and housing) and just the slug element. The analytical solutions are presented in a general sense and in a truncated form from error analysis. Results are shown in optimizing and validating the analytical models against available slug back-face thermal data. The optimization results indicate that the appropriate epistemic uncertainty of the deduced stagnation heat flux on the slug calorimeter is at most±2.5% for both a high-and low-enthalpy test condition. In addition, a numerical approach is used to determine the aleatory (probabilistic) uncertainty component in the slug stagnation heat flux by applying a marching least-squares slope routine through the steady-state portion of the slug back-face thermal response. Results indicate a compromise between the number of samples and the filter frequency of slug back-face thermal data points when evaluating the standard deviation of the deduced stagnation heat flux statistics. When combining the mixed uncertainty, both aleatory and epistemic, the interval of uncertainty in the deduced stagnation heat flux is determined to be up to ±4%, which is at least a 60% reduction from the standard uncertainty used in the state-of-the-art method.
Document ID
20230006293
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Chelsey C Morrow
(Universities Space Research Association Columbia, Maryland, United States)
Andrew J Brune
(Langley Research Center Hampton, Virginia, United States)
Date Acquired
April 24, 2023
Publication Date
June 12, 2023
Subject Category
Research and Support Facilities (Air)
Meeting Information
Meeting: AIAA Aviation and Aeronautics Forum and Exposition
Location: San Diego, CA
Country: US
Start Date: June 12, 2023
End Date: June 16, 2023
Sponsors: American Institute of Aeronautics and Astronautics
Funding Number(s)
WBS: 031102.02.07.01.9SO3.21
Distribution Limits
Public
Copyright
Portions of document may include copyright protected material.
Technical Review
Single Expert
Keywords
uncertainty
arc-jet
test facility
test environments
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