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One-Dimensional Modeling Methodology for Shock Tubes: Application to the EAST FacilityIn this work, a one-dimensional methodology for simulating shock tubes is developed. The model accounts for the viscous interactions of the shock with the shock tube wall by adding an area change source term in the 1-D conservation equations corresponding to the boundary layer growth. This source term corresponds to the mass and energy going into the boundary layer. The boundary layer growth is computed using a simple model with a scaling factor. This scale factor is used to tailor a solution to match the deceleration profile of a shock tube test. In doing so, not only will the source term take into account boundary layer losses, it will also cover any effect due to radiative cooling loses from the gas. For this study, the Electric Arc Shock Tube(EAST) facility at NASA Ames Research Center is modeled for Earth reentry conditions. The purpose of this paper is to investigate if anomalies identified for certain conditions in the EAST data are due to shock deceleration. These anomalies include measuring electron number density above equilibrium predictions and observing that radiance profiles can continually increase behind the shock, never reach steady state, for certain shots (typically those less than 10 km/s). An eleven species air mixture is chosen to study the chemistry of the flow. Comparisons of the simulations to the experimental results are presented. Good agreement with the shock deceleration profiles was achieved by tuning in the boundary layer scale factor. The temperature as well as electron number density increases behind the shock, as has also been observed in the experiments. Finally, radiance comparisons between results from NEQAIR and experiments also show good agreement for some shots, but significant discrepancies are still observed for others.
Document ID
20180006862
Acquisition Source
Ames Research Center
Document Type
Presentation
Authors
Sharma, Maitreyee (Illinois Univ. at Urbana-Champaign Urbana, IL, United States)
Munafo, Alessandro (Illinois Univ. at Urbana-Champaign Urbana, IL, United States)
Panesi, Marco (Illinois Univ. at Urbana-Champaign Urbana, IL, United States)
Brandis, Aaron (Analytical Mechanics Associates, Inc. Moffett Field, CA, United States)
Cruden, Brett A. (Analytical Mechanics Associates, Inc. Moffett Field, CA, United States)
Date Acquired
October 25, 2018
Publication Date
June 29, 2018
Subject Category
Fluid Mechanics And Thermodynamics
Report/Patent Number
ARC-E-DAA-TN58197
Meeting Information
Meeting: AIAA Aviation Forum
Location: Atlanta, GA
Country: United States
Start Date: June 25, 2018
End Date: June 29, 2018
Sponsors: American Inst. of Aeronautics and Astronautics
Funding Number(s)
CONTRACT_GRANT: NNX15AU44G
CONTRACT_GRANT: NNA15BB15C
Distribution Limits
Public
Copyright
Public Use Permitted.

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