2026-09-19T17:16:15Zhttps://dspace.mit.edu/server/oai/request

oai:dspace.mit.edu:1721.1/1056102022-01-13T07:53:53Zcom_1721.1_7582com_1721.1_7581col_1721.1_131023

Qiqi Wang. Chater, Mario Massachusetts Institute of Technology. Department of Aeronautics and Astronautics. Massachusetts Institute of Technology. Department of Aeronautics and Astronautics 2016-12-05T19:54:51Z 2016-12-05T19:54:51Z 2016 2016 http://hdl.handle.net/1721.1/105610 962486214 Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2016. Cataloged from PDF version of thesis. Includes bibliographical references (pages 85-87). In numerous scientific and engineering fields, sensitivity analysis tools are essential for design optimization as well as uncertainty quantification. For instance, adjoint algorithms are common place in aerospace engineering when it comes to optimize the shape of an airfoil, the configuration of a rocket or to quantify the impact of a manufacturing imperfection on the performance of a product. The quantities of interest are long-time averaged outputs such as the average drag on a plane wing. However, these conventional methods fail to compute the right sensitivity when the physical model exhibits chaos. This is the case of many turbulent fluid flows and atmospheric modelisations. A recently developed method, Least Squares Shadowing or simply LSS, tackles this problem and proposes an alternative approach to compute the desired sensitivities. The results are very promising and this thesis is intended to lay the mathematical foundations of this new algorithm. A latter part is dedicated to some improvements of LSS which make it faster and more reliable. by Mario Chater. S.M. 87 pages eng Massachusetts Institute of Technology M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 Aeronautics and Astronautics. Least Squares Shadowing for sensitivity analysis of chaotic dynamical systems Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="b27f7222-c040-41f6-aed4-55ce709d426f"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Least Squares Shadowing for sensitivity analysis of chaotic dynamical systems</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2016</PublicationDate> <Authors> <Author> <DisplayName>Chater, Mario</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Aeronautics and Astronautics.</Keyword> <Abstract>In numerous scientific and engineering fields, sensitivity analysis tools are essential for design optimization as well as uncertainty quantification. For instance, adjoint algorithms are common place in aerospace engineering when it comes to optimize the shape of an airfoil, the configuration of a rocket or to quantify the impact of a manufacturing imperfection on the performance of a product. The quantities of interest are long-time averaged outputs such as the average drag on a plane wing. However, these conventional methods fail to compute the right sensitivity when the physical model exhibits chaos. This is the case of many turbulent fluid flows and atmospheric modelisations. A recently developed method, Least Squares Shadowing or simply LSS, tackles this problem and proposes an alternative approach to compute the desired sensitivities. The results are very promising and this thesis is intended to lay the mathematical foundations of this new algorithm. A latter part is dedicated to some improvements of LSS which make it faster and more reliable.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>