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Assessment of Spacecraft Aerodynamics under Uncertainty toward the Optimization of Atmospheric Entry Trajectories.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	Assessment of Spacecraft Aerodynamics under Uncertainty toward the Optimization of Atmospheric Entry Trajectories./
Author:	Mesalles Ripoll, Pol.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2021,
Description:	247 p.
Notes:	Source: Masters Abstracts International, Volume: 83-01.
Contained By:	Masters Abstracts International83-01.
Subject:	Aerospace engineering. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28316092
ISBN:	9798516927560

Assessment of Spacecraft Aerodynamics under Uncertainty toward the Optimization of Atmospheric Entry Trajectories.
Mesalles Ripoll, Pol.

Assessment of Spacecraft Aerodynamics under Uncertainty toward the Optimization of Atmospheric Entry Trajectories. - Ann Arbor : ProQuest Dissertations & Theses, 2021 - 247 p.

Source: Masters Abstracts International, Volume: 83-01.

Thesis (M.S.)--University of Colorado at Boulder, 2021.

This item must not be sold to any third party vendors.

The complex physics of planetary entry make it infeasible to couple the simulation of a spacecraft's trajectory with its gas dynamics in most scenarios. To compute entry trajectories, databases that provide experimental and CFD/DSMC aerodynamic coefficients are typically employed. In this work, we first develop a 6-degree-of-freedom solver that integrates the flight mechanics equations of motion using one such database and that has support for multiple atmospheric and geodesy models, as well as bank-angle modulation. Then, we generate three different hypersonic aerothermodynamic databases for the Apollo command module—one based on the Knudsen number, another on the Mach number, and a third that uses results from new DSMC simulations to compute the coefficients as a function of ɑ, M, and Kn. The performance of each database approach is compared in both lifting and skip entry trajectories by studying the case of a lunar return mission reentry. Additionally, effects of uncertainty in the aerodynamic coefficients during the propagation of entry trajectories are presented for each database. In terms of quantities of interest, focus is put on the final range of the trajectory at parachute deployment altitude and associated velocity, as well as maximum heat flux and deceleration, integrated heat load, and flight duration. The results show that uncertainty in the hypersonic continuum phase of flight has the largest influence on the aforementioned quantities, and while uncertainty in the slip and rarefied regimes is found to not be relevant, the dependence of the database on the Knudsen number is, particularly for skip entries. Finally, the developed tools are used to assess how reinforcement learning techniques can be used to maximize the range of skip entry trajectories while still ensuring that the spacecraft is safely captured by the atmosphere and the entry profile does not exceed design requirements.

ISBN: 9798516927560Subjects--Topical Terms:

686400
Aerospace engineering.
Subjects--Index Terms:

Aerodynamics

Assessment of Spacecraft Aerodynamics under Uncertainty toward the Optimization of Atmospheric Entry Trajectories.
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300 $a 247 p.
500 $a Source: Masters Abstracts International, Volume: 83-01.
500 $a Advisor: Argrow, Brian M.
502 $a Thesis (M.S.)--University of Colorado at Boulder, 2021.
506 $a This item must not be sold to any third party vendors.
520 $a The complex physics of planetary entry make it infeasible to couple the simulation of a spacecraft's trajectory with its gas dynamics in most scenarios. To compute entry trajectories, databases that provide experimental and CFD/DSMC aerodynamic coefficients are typically employed. In this work, we first develop a 6-degree-of-freedom solver that integrates the flight mechanics equations of motion using one such database and that has support for multiple atmospheric and geodesy models, as well as bank-angle modulation. Then, we generate three different hypersonic aerothermodynamic databases for the Apollo command module—one based on the Knudsen number, another on the Mach number, and a third that uses results from new DSMC simulations to compute the coefficients as a function of ɑ, M, and Kn. The performance of each database approach is compared in both lifting and skip entry trajectories by studying the case of a lunar return mission reentry. Additionally, effects of uncertainty in the aerodynamic coefficients during the propagation of entry trajectories are presented for each database. In terms of quantities of interest, focus is put on the final range of the trajectory at parachute deployment altitude and associated velocity, as well as maximum heat flux and deceleration, integrated heat load, and flight duration. The results show that uncertainty in the hypersonic continuum phase of flight has the largest influence on the aforementioned quantities, and while uncertainty in the slip and rarefied regimes is found to not be relevant, the dependence of the database on the Knudsen number is, particularly for skip entries. Finally, the developed tools are used to assess how reinforcement learning techniques can be used to maximize the range of skip entry trajectories while still ensuring that the spacecraft is safely captured by the atmosphere and the entry profile does not exceed design requirements.
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653 $a Aerodynamics
653 $a EDL
653 $a Hypersonics
653 $a Machine learning
653 $a Trajectory simulation
653 $a Uncertainty quantification
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690 $a 0537
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773 0 $t Masters Abstracts International $g 83-01.
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791 $a M.S.
792 $a 2021
793 $a English
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