An investigation was conducted into the feasibility of using an unconventional flight technique, asymmetric flight, to improve overall efficiency of solar aircraft. In this study, asymmetric flight is defined as steady level flight in a non-wings-level state in- tended to improve solar incidence angle. By manipulating aircraft orientation through roll angle, solar energy collection is improved but aerodynamic efficiency is worsened due to the introduction of additional trim drag. A point performance model was devel- oped to investigate the trade-off between improvement in solar energy collection and additional drag associated with asymmetric flight. A mission model with a focus on aircraft orbits was then developed via integration of the point performance model over a set of discrete points.
It is shown that there is a non-zero bank angle where optimal net power is achieved for a given aircraft orientation, flight condition, and sun position. The study also shows that there is improvement in overall efficiency over conventional flight for various orbit shapes and winds aloft. This indicates that there is potential value in not only flight path planning, but also in orientation planning for solar aircraft.
","abstract_html":"<p>An investigation was conducted into the feasibility of using an unconventional flight technique, asymmetric flight, to improve overall efficiency of solar aircraft. In this study, asymmetric flight is defined as steady level flight in a non-wings-level state in- tended to improve solar incidence angle. By manipulating aircraft orientation through roll angle, solar energy collection is improved but aerodynamic efficiency is worsened due to the introduction of additional trim drag. A point performance model was devel- oped to investigate the trade-off between improvement in solar energy collection and additional drag associated with asymmetric flight. A mission model with a focus on aircraft orbits was then developed via integration of the point performance model over a set of discrete points.</p> <p>It is shown that there is a non-zero bank angle where optimal net power is achieved for a given aircraft orientation, flight condition, and sun position. The study also shows that there is improvement in overall efficiency over conventional flight for various orbit shapes and winds aloft. This indicates that there is potential value in not only flight path planning, but also in orientation planning for solar aircraft.</p>","abstract_has_math":false,"creators":["Belfield, Eric"],"institution":null,"degree_name":"MS in Aerospace Engineering","degree_level":null,"degree_discipline":"Aerospace Engineering","degree_department":null,"school":null,"contributors":["Aaron Drake"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-12-01T08:00:00Z","date_published":"2016-12-01T08:00:00Z","updated_at":"2026-07-24T01:31:49Z","subjects":["asymmetric flight","aircraft performance","solar aircraft","UAS","Aerodynamics and Fluid Mechanics","Aeronautical Vehicles","Navigation, Guidance, Control and Dynamics","Other Aerospace Engineering"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10.15368/theses.2016.149"],"render_values":[{"text":"10.15368/theses.2016.149","href":"https://doi.org/10.15368/theses.2016.149","code":true}]}]},"links":{"outbound_url":"https://digitalcommons.calpoly.edu/theses/1676","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Aaron Drake"]},{"key":"dc:creator","label":"Author","values":["Belfield, Eric"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2016-12-09T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"key":"thesis:degree_name","label":"Degree Name","values":["MS in Aerospace Engineering"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["asymmetric flight","aircraft performance","solar aircraft","UAS","Aerodynamics and Fluid Mechanics","Aeronautical Vehicles","Navigation, Guidance, Control and Dynamics","Other Aerospace Engineering"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.calpoly.edu/theses/1676","10.15368/theses.2016.149"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["An investigation was conducted into the feasibility of using an unconventional flight technique, asymmetric flight, to improve overall efficiency of solar aircraft. In this study, asymmetric flight is defined as steady level flight in a non-wings-level state in- tended to improve solar incidence angle. By manipulating aircraft orientation through roll angle, solar energy collection is improved but aerodynamic efficiency is worsened due to the introduction of additional trim drag. A point performance model was devel- oped to investigate the trade-off between improvement in solar energy collection and additional drag associated with asymmetric flight. A mission model with a focus on aircraft orbits was then developed via integration of the point performance model over a set of discrete points.
It is shown that there is a non-zero bank angle where optimal net power is achieved for a given aircraft orientation, flight condition, and sun position. The study also shows that there is improvement in overall efficiency over conventional flight for various orbit shapes and winds aloft. This indicates that there is potential value in not only flight path planning, but also in orientation planning for solar aircraft.
"]},{"key":"dc:title","label":"Title","values":["Assessment of Asymmetric Flight on Solar UAS"]}]}],"canonical_facts":{"dc:contributor":["Aaron Drake"],"dc:creator":["Belfield, Eric"],"dc:date.available":["2016-12-09T08:00:00Z"],"dc:description.abstract":["An investigation was conducted into the feasibility of using an unconventional flight technique, asymmetric flight, to improve overall efficiency of solar aircraft. In this study, asymmetric flight is defined as steady level flight in a non-wings-level state in- tended to improve solar incidence angle. By manipulating aircraft orientation through roll angle, solar energy collection is improved but aerodynamic efficiency is worsened due to the introduction of additional trim drag. A point performance model was devel- oped to investigate the trade-off between improvement in solar energy collection and additional drag associated with asymmetric flight. A mission model with a focus on aircraft orbits was then developed via integration of the point performance model over a set of discrete points.
It is shown that there is a non-zero bank angle where optimal net power is achieved for a given aircraft orientation, flight condition, and sun position. The study also shows that there is improvement in overall efficiency over conventional flight for various orbit shapes and winds aloft. This indicates that there is potential value in not only flight path planning, but also in orientation planning for solar aircraft.
"],"dc:identifier":["https://digitalcommons.calpoly.edu/theses/1676","10.15368/theses.2016.149"],"dc:subject":["asymmetric flight","aircraft performance","solar aircraft","UAS","Aerodynamics and Fluid Mechanics","Aeronautical Vehicles","Navigation, Guidance, Control and Dynamics","Other Aerospace Engineering"],"dc:title":["Assessment of Asymmetric Flight on Solar UAS"],"thesis:degree_discipline":["Aerospace Engineering"],"thesis:degree_name":["MS in Aerospace Engineering"]},"updated_at":"2026-07-24T01:31:49Z"}