PCM https://www.crtech.com/ en Analysis of Post-reentry Heating and Soak-back Affects in Unsealed Reentry Vehicles https://www.crtech.com/analysis-post-reentry-heating-and-soak-back-affects-unsealed-reentry-vehicles <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--title--publication-files.html.twig x field--node--title.html.twig * field--node--publication-files.html.twig * field--title.html.twig * field--string.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/classy/field/field--node--title.html.twig' --> <span class="field field--name-title field--type-string field--label-hidden">Analysis of Post-reentry Heating and Soak-back Affects in Unsealed Reentry Vehicles</span> <!-- END OUTPUT from 'themes/crtechd9/templates/classy/field/field--node--title.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--uid--publication-files.html.twig x field--node--uid.html.twig * field--node--publication-files.html.twig * field--uid.html.twig * field--entity-reference.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/classy/field/field--node--uid.html.twig' --> <span class="field field--name-uid field--type-entity-reference field--label-hidden"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'username' --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/classy/user/username.html.twig' --> <span lang="" about="/user/1" typeof="schema:Person" property="schema:name" datatype="">bfc-admin</span> <!-- END OUTPUT from 'themes/crtechd9/templates/classy/user/username.html.twig' --> </span> <!-- END OUTPUT from 'themes/crtechd9/templates/classy/field/field--node--uid.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--created--publication-files.html.twig x field--node--created.html.twig * field--node--publication-files.html.twig * field--created.html.twig * field--created.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/classy/field/field--node--created.html.twig' --> <span class="field field--name-created field--type-created field--label-hidden"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'time' --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/classy/field/time.html.twig' --> <time datetime="2015-07-15T16:23:40-04:00" title="Wednesday, July 15, 2015 - 16:23" class="datetime">Wed, 07/15/2015 - 16:23</time> <!-- END OUTPUT from 'themes/crtechd9/templates/classy/field/time.html.twig' --> </span> <!-- END OUTPUT from 'themes/crtechd9/templates/classy/field/field--node--created.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'links__node' --> <!-- FILE NAME SUGGESTIONS: x links--node.html.twig x links--node.html.twig * links.html.twig --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/classy/content/links--node.html.twig' --> <!-- END OUTPUT from 'themes/crtechd9/templates/classy/content/links--node.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--body--publication-files.html.twig * field--node--body.html.twig * field--node--publication-files.html.twig * field--body.html.twig x field--text-with-summary.html.twig * field.html.twig --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/classy/field/field--text-with-summary.html.twig' --> <div class="clearfix text-formatted field field--name-body field--type-text-with-summary field--label-hidden field__item"><p>Maintaining low temperature payloads through atmospheric reentry and ground recovery is becoming a larger focus in the space program as work in biology, cryogenic and other temperature dependent sciences becomes a higher goal on the International Space Station (ISS) and extraterrestrial surfaces. Paragon analyzes reentry system thermal control, particularly technology regarding small thermally controlled payloads anticipated for use in sample return from the International Space Station.</p> <p>To minimize system mass and utilize the powerful insulative properties of a hard space vacuum the internal cavity of a small reentry vehicle can be left open. Thermally this causes concern during reentry, as even at very high altitudes there is enough pressure to cause a significant impact on insulation stratagems, such as MLI that rely on a high vacuum. At lower altitudes the vehicle is moving much slower, so the intense heat load of reentry is finished but soak-back from outer heated surfaces to the payload is a significant issue when air is present to facilitate heat transfer between layers. Initial assumptions that the cold temperatures of the upper atmosphere would cause a net cooling affect in the post-reentry times were overturned by a simple analysis set done in Thermal Desktop involving worst and best case scenarios as air starts to enter the vehicle. Additionally, CFD low pressure zones were shown to exist behind the vehicle where it is open to the atmosphere when the vehicle is travelling at extreme reentry speeds. These pressures are not so low however to prevent air from entering the vehicle. The impacts of this now apparent soak back, during the last phases of an atmospheric reentry were investigated leading to the conclusion that analyses of lower atmospheric portions of a reentry are critical to reentry studies and significantly changed the results.</p> <p>An updated design is theorized using the knowledge gained from the preliminary studies called the Cryogenic Extended Duration and Reentry Thermal Control System (CEDR TCS) and the design is fully passive making it a low-complexity, zero-power system that does not necessitate the use of any consumables. The CEDR TCS uses a two-way pressure relief valve or “breather valve” that would allow the pressures inside and outside the vehicle to equilibrate once a great enough pressure differential is applied. This will allow air to leave while the unit is in space vacuum and prevent air from coming in until much later in the re-entry after much of the reentry heat has had a chance to convect to the upper atmosphere. Through further analysis CEDR is hoped to display a capability of near cryogenic temperatures through an atmospheric reentry and long durations on the ground.</p> </div> <!-- END OUTPUT from 'themes/crtechd9/templates/classy/field/field--text-with-summary.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-upload-files--publication-files.html.twig * field--node--field-upload-files.html.twig * field--node--publication-files.html.twig * field--field-upload-files.html.twig * field--file.html.twig x field.html.twig --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/classy/field/field.html.twig' --> <div class="field field--name-field-upload-files field--type-file field--label-inline clearfix"> <div class="field__label">Upload Files</div> <div class="field__item"> <!-- THEME DEBUG --> <!-- THEME HOOK: 'file_link' --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/field/file-link.html.twig' --> <span class="file file--mime-application-pdf file--application-pdf"> <a href="/sites/default/files/publications/TFAWS2011-AE-005_0.pdf" type="application/pdf">TFAWS2011-AE-005.pdf</a></span> <!-- END OUTPUT from 'themes/crtechd9/templates/field/file-link.html.twig' --> </div> </div> <!-- END OUTPUT from 'themes/crtechd9/templates/classy/field/field.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-source--publication-files.html.twig * field--node--field-source.html.twig * field--node--publication-files.html.twig * field--field-source.html.twig * field--string.html.twig x field.html.twig --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/classy/field/field.html.twig' --> <div class="field field--name-field-source field--type-string field--label-inline clearfix"> <div class="field__label">Source</div> <div class="field__item">TFAWS</div> </div> <!-- END OUTPUT from 'themes/crtechd9/templates/classy/field/field.html.twig' --> <!-- THEME DEBUG --> <!-- THEME HOOK: 'field' --> <!-- FILE NAME SUGGESTIONS: * field--node--field-author--publication-files.html.twig * field--node--field-author.html.twig * field--node--publication-files.html.twig * field--field-author.html.twig * field--string.html.twig x field.html.twig --> <!-- BEGIN OUTPUT from 'themes/crtechd9/templates/classy/field/field.html.twig' --> <div class="field field--name-field-author field--type-string field--label-inline clearfix"> <div class="field__label">Author</div> <div class="field__item">Erika T. Bannon, Jared Leidich, Alex Walker</div> </div> <!-- END OUTPUT from 'themes/crtechd9/templates/classy/field/field.html.twig' --> Wed, 15 Jul 2015 20:23:40 +0000 bfc-admin 1194 at https://www.crtech.com