國立虎尾科技大學 |

Analysis Methods for Reusable Spacecraft Undergoing Aeroassist Maneuvers.

紀錄類型:	書目-語言資料,印刷品 : Monograph/item
正題名/作者:	Analysis Methods for Reusable Spacecraft Undergoing Aeroassist Maneuvers./
作者:	Campbell, N. S.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2019,
面頁冊數:	246 p.
附註:	Source: Dissertations Abstracts International, Volume: 81-05, Section: B.
Contained By:	Dissertations Abstracts International81-05B.
標題:	Aerospace engineering. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=22615008
ISBN:	9781088377185

Analysis Methods for Reusable Spacecraft Undergoing Aeroassist Maneuvers.
Campbell, N. S.

Analysis Methods for Reusable Spacecraft Undergoing Aeroassist Maneuvers. - Ann Arbor : ProQuest Dissertations & Theses, 2019 - 246 p.

Source: Dissertations Abstracts International, Volume: 81-05, Section: B.

Thesis (Ph.D.)--University of Colorado at Boulder, 2019.

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

Recent growth in commercial space operations provides exciting new challenges for the aerospace engineering community. In particular, increased orbital and sub-orbital activity represents high-speed flight design and mission planning efforts, which require the highest quality of predictive analysis tools to ensure safe and cost-effective performance. Along with the typical applications, such as ascent or entry, a recent proposal from United Launch Alliance (ULA) to re-use upper-stage spacecraft for in-space transportation services represents another application potentially requiring high-energy flight operations. The prospect of lunar-mined water promotes the establishment of in-space transportation infrastructure, which will enable the lunar mining market to receive supplies and send out product. Regular cargo transfers from the Earth-Moon Lagrange Point 1 (EML1) back to Low Earth Orbit (LEO) then motivates the use of aerobraking to save propellant or to increase payload mass fraction.Aerobraking is an aeroassist maneuver where atmospheric drag is used to decelerate and shed the necessary amount of excess velocity gained, in this case, while dropping in from EML1. Flight for such maneuvers occurs at high-altitudes where the atmospheric properties vary rapidly throughout the trajectory. Orbital vehicles entering an atmosphere have incredibly high kinetic energy, which results in nonequilibrium flowfields that exchange momentum and energy with the spacecraft surface in proportions that can depart from experience and intuition. In 2016, ULA teamed up with the University of Colorado to investigate these complexities and estimate the potential feasibility and benefits of aerobraking their next generation upper stage. Preliminary estimates predicted 90% of propellant could be saved using aerobraking in the transfer from EML1 to LEO (as compared to a fully propulsive transfer). However, this estimate did not provide an accurate or precise look into the thermal response of the spacecraft.In this work, the concept of aerobraking a vehicle resembling ULA's planned Advanced Cryogenic Evolved Stage (ACES) spacecraft is investigated. In order to estimate the amount of heat being absorbed during aerobraking, the author implemented and coupled models for the underlying loads on the vehicle, the resulting flight trajectories based on various orbital states and spacecraft configurations, and the thermal response of the spacecraft structure. Any energy transferred to the cryogenic propellant results in boil-off leading to wasted propellant when vented to maintain tank pressures below structural limits. Since it is also important to ensure wall temperatures stay below material limits, the prospect of using gaseous propellant to cool the body before being vented, is also considered. Where necessary, new methods were developed.Multi-mode heat transfer models that can incorporate results from an aerospace loads database and couple to an aerobraking trajectory solver were investigated in order to compare spacecraft-component material selections and the effect of targeted cooling on different sections of the three-dimensional wall geometry. An Augmented Temperature (AT) model was devised to estimate a traditional, fully discrete solution to the conservation of energy in the spacecraft's structure. Tests performed with simple geometries show the AT model can provide precise estimates in a number of cases while remaining conservative in regions of identified breakdown. Most importantly, the method enables the coupled trajectory-thermal response models to solve in less time than the fully discrete solution, by orders of magnitude. This enables large batches of trajectories to be computed in a timely fashion. As a result, more design configurations or cooling options can be tested in a given amount of time. To put this benefit into context, for a batch computation of 750 aerobraking trajectories of a sphere discretized to 104 elements, the traditional scheme would take just under six days to complete. The AT method for this same surface mesh would be expected to take only nine minutes.In the end, an extensive set of simulated aerobraking trajectories enabled a trade study regarding various ACES configurations making the orbital transfer from EML1 to LEO. This trade study reveals the importance of a decreased vehicle ballistic coefficient, on-board cooling options, and targeting strategy on the resulting propellant savings. Savings are defined relative to a standard, propulsive transfer. Targeting motor efficiency is also shown to be an important factor, especially if short duration transfers are desired. Only ballistic, fixed-attitude trajectories were investigated, as they provide a worst-case representation of feasible aerobraking corridors. Overall, this culminated in a number of cases showing savings of 10% and greater. In a few cases, values of over 50% savings were realized, with the maximum case being 72% savings.

ISBN: 9781088377185Subjects--Topical Terms:

686400
Aerospace engineering.
Subjects--Index Terms:

Aeroassist

Analysis Methods for Reusable Spacecraft Undergoing Aeroassist Maneuvers.
LDR:06132nam a2200361 4500 001 951850
005 20200821052209.5
008 200914s2019 ||||||||||||||||| ||eng d
020 $a 9781088377185
035 $a (MiAaPQ)AAI22615008
035 $a AAI22615008
040 $a MiAaPQ $c MiAaPQ
100 1 $a Campbell, N. S. $3 1241340
245 1 0 $a Analysis Methods for Reusable Spacecraft Undergoing Aeroassist Maneuvers.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2019
300 $a 246 p.
500 $a Source: Dissertations Abstracts International, Volume: 81-05, Section: B.
500 $a Advisor: Argrow, Brian M.
502 $a Thesis (Ph.D.)--University of Colorado at Boulder, 2019.
506 $a This item must not be sold to any third party vendors.
520 $a Recent growth in commercial space operations provides exciting new challenges for the aerospace engineering community. In particular, increased orbital and sub-orbital activity represents high-speed flight design and mission planning efforts, which require the highest quality of predictive analysis tools to ensure safe and cost-effective performance. Along with the typical applications, such as ascent or entry, a recent proposal from United Launch Alliance (ULA) to re-use upper-stage spacecraft for in-space transportation services represents another application potentially requiring high-energy flight operations. The prospect of lunar-mined water promotes the establishment of in-space transportation infrastructure, which will enable the lunar mining market to receive supplies and send out product. Regular cargo transfers from the Earth-Moon Lagrange Point 1 (EML1) back to Low Earth Orbit (LEO) then motivates the use of aerobraking to save propellant or to increase payload mass fraction.Aerobraking is an aeroassist maneuver where atmospheric drag is used to decelerate and shed the necessary amount of excess velocity gained, in this case, while dropping in from EML1. Flight for such maneuvers occurs at high-altitudes where the atmospheric properties vary rapidly throughout the trajectory. Orbital vehicles entering an atmosphere have incredibly high kinetic energy, which results in nonequilibrium flowfields that exchange momentum and energy with the spacecraft surface in proportions that can depart from experience and intuition. In 2016, ULA teamed up with the University of Colorado to investigate these complexities and estimate the potential feasibility and benefits of aerobraking their next generation upper stage. Preliminary estimates predicted 90% of propellant could be saved using aerobraking in the transfer from EML1 to LEO (as compared to a fully propulsive transfer). However, this estimate did not provide an accurate or precise look into the thermal response of the spacecraft.In this work, the concept of aerobraking a vehicle resembling ULA's planned Advanced Cryogenic Evolved Stage (ACES) spacecraft is investigated. In order to estimate the amount of heat being absorbed during aerobraking, the author implemented and coupled models for the underlying loads on the vehicle, the resulting flight trajectories based on various orbital states and spacecraft configurations, and the thermal response of the spacecraft structure. Any energy transferred to the cryogenic propellant results in boil-off leading to wasted propellant when vented to maintain tank pressures below structural limits. Since it is also important to ensure wall temperatures stay below material limits, the prospect of using gaseous propellant to cool the body before being vented, is also considered. Where necessary, new methods were developed.Multi-mode heat transfer models that can incorporate results from an aerospace loads database and couple to an aerobraking trajectory solver were investigated in order to compare spacecraft-component material selections and the effect of targeted cooling on different sections of the three-dimensional wall geometry. An Augmented Temperature (AT) model was devised to estimate a traditional, fully discrete solution to the conservation of energy in the spacecraft's structure. Tests performed with simple geometries show the AT model can provide precise estimates in a number of cases while remaining conservative in regions of identified breakdown. Most importantly, the method enables the coupled trajectory-thermal response models to solve in less time than the fully discrete solution, by orders of magnitude. This enables large batches of trajectories to be computed in a timely fashion. As a result, more design configurations or cooling options can be tested in a given amount of time. To put this benefit into context, for a batch computation of 750 aerobraking trajectories of a sphere discretized to 104 elements, the traditional scheme would take just under six days to complete. The AT method for this same surface mesh would be expected to take only nine minutes.In the end, an extensive set of simulated aerobraking trajectories enabled a trade study regarding various ACES configurations making the orbital transfer from EML1 to LEO. This trade study reveals the importance of a decreased vehicle ballistic coefficient, on-board cooling options, and targeting strategy on the resulting propellant savings. Savings are defined relative to a standard, propulsive transfer. Targeting motor efficiency is also shown to be an important factor, especially if short duration transfers are desired. Only ballistic, fixed-attitude trajectories were investigated, as they provide a worst-case representation of feasible aerobraking corridors. Overall, this culminated in a number of cases showing savings of 10% and greater. In a few cases, values of over 50% savings were realized, with the maximum case being 72% savings.
590 $a School code: 0051.
650 4 $a Aerospace engineering. $3 686400
653 $a Aeroassist
653 $a Aerobraking
653 $a Aerothermodynamics
653 $a Heat transfer
653 $a Hypersonic
653 $a Orbital transfers
690 $a 0538
710 2 $a University of Colorado at Boulder. $b Aerospace Engineering. $3 1179005
773 0 $t Dissertations Abstracts International $g 81-05B.
790 $a 0051
791 $a Ph.D.
792 $a 2019
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=22615008