
Penn State University
1.
Kimmel, Nathan.
A Method for the Exploitation of Microlift for Unmanned Aerial Vehicles.
Degree: 2019, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/17352npk5048
Disorganized convective structures in the lower part of the atmospheric boundary layer (sometimes called microlift) are recognized as a viable source of energy for manned ultralight sailplanes and high performance hang gliders, and species of soaring birds have been observed to make use of microlift. However, this source of energy remains largely underutilized by autonomous soaring aircraft, and the techniques used to (often incidentally) exploit it are not specifically designed for microlift soaring. Analyzing surveys of the atmosphere and large eddy simulations of the convective boundary layer indicate the presence of long, linear regions of lift that are a potential significant source of energy and present the opportunity for energy extraction without the need to loiter.
This thesis investigates techniques for energy extraction from these structures - referred to as spoke-like structures, thermal walls, thermal streams, or thermal stands - that can be implemented onboard an autonomous microlift soaring aircraft. The primary focus of this thesis is a Kalman filter designed to estimate the location, orientation, and characteristics of a thermal strand. This estimator was then integrated into a flight controller and tested in a realistic wind field obtained from a large eddy simulation of the convective boundary layer.
The choice of a Kalman filter is supported in this thesis by showing that several basic techniques for following a thermal strand are unstable. Furthermore, an idealized model of a thermal strand is developed for estimator and controller design, and various methods of estimating the initial thermal strand state for the Kalman filter are developed and tested in simulation.
Advisors/Committee Members: Jacob Willem Langelaan, Thesis Advisor/Co-Advisor, Amy Ruth Pritchett, Program Head/Chair, Mark David Maughmer, Committee Member.
Subjects/Keywords: autonomy; soaring; microlift; thermal; thermal wall; thermal stream; thermal strand; autonomous; uav; autonomous soaring
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share





❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kimmel, N. (2019). A Method for the Exploitation of Microlift for Unmanned Aerial Vehicles. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/17352npk5048
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kimmel, Nathan. “A Method for the Exploitation of Microlift for Unmanned Aerial Vehicles.” 2019. Thesis, Penn State University. Accessed March 07, 2021.
https://submit-etda.libraries.psu.edu/catalog/17352npk5048.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kimmel, Nathan. “A Method for the Exploitation of Microlift for Unmanned Aerial Vehicles.” 2019. Web. 07 Mar 2021.
Vancouver:
Kimmel N. A Method for the Exploitation of Microlift for Unmanned Aerial Vehicles. [Internet] [Thesis]. Penn State University; 2019. [cited 2021 Mar 07].
Available from: https://submit-etda.libraries.psu.edu/catalog/17352npk5048.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kimmel N. A Method for the Exploitation of Microlift for Unmanned Aerial Vehicles. [Thesis]. Penn State University; 2019. Available from: https://submit-etda.libraries.psu.edu/catalog/17352npk5048
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Southern California
2.
Becker, Geoffrey S.
ctrl+z: exploring the effects of undoing retrofits to
pre-war buildings in Los Angeles.
Degree: Master of Building Science, Building Science, 2015, University of Southern California
URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/610190/rec/1720
To achieve the 80% statewide greenhouse gas reduction
target mandated by California Executive Order S-3-05, the existing
building stock must become 40% more energy efficient by 2030.
Meeting the target for existing buildings will require deep energy
retrofits to the 465-million square meters of existing commercial
building stock in the next 15 years. While studies have shown that
energy retrofits leading to reductions as high as 28% are possible
in a cost-effective manner, and that “deep” energy retrofits can
achieve even greater reduction, these recommendations are often
poorly applicable to historic buildings for two reasons. First, the
recommendations nearly always promote incremental improvements to a
sealed building envelope and efficiency upgrades to mechanical HVAC
and lighting systems. This approach overlooks the possibility of
meeting energy reduction targets simply by re-activating the
passive strategies present in many historic structures, which have
largely been de-activated over time following past renovations
which introducing air conditioning and fluorescent lighting
technologies. Second, many retrofit recommendations would alter the
character of historic structures to an extent that would be
unacceptable to preservationists, the public, and existing historic
preservation laws. ❧ Because a large portion of the existing
commercial building stock in Downtown Los Angeles was built before
1950 and originally designed to rely on the local climate for most
Indoor Environmental Quality (IEQ) needs, an alternate approach to
deep energy retrofits is needed which begins by examining the
energy reductions achievable through re-activation of these
original passive strategies. ❧ To address this need, a
simulation-based framework was developed to compare annual energy
and IEQ outcomes from re-activation of multiple passive strategies.
Detailed building information on LA’s Subway Terminal Building
(with observational analysis of ten additional pre-1950s buildings)
was used as a basis to develop the initial baseline model and
identify original passive design strategies (e.g. exterior solar
control, daylighting, and natural ventilation). Energy and daylight
simulations using the EnergyPlus and Radiance engines are used to
quantify annual performance outcomes from a parametric exploration
of retrofit combinations that replicate and improve upon the
original passive design intent of the historic building type.
Compared to the baseline model, implementation of the best set of
passive retrofits was found to yield a reduction in Energy Use
Intensity (EUI) of 29%. Due to the typical design conventions of
this building type, a parametric model was developed to extrapolate
the potential of re-activating passive strategies for additional
historic buildings. Analysis of the metric thermal autonomy
revealed that thermal comfort conditions can be met in pre-1950s
buildings for large periods (up to 67%) of occupied hours utilizing
only passive conditioning. Analysis of the metric daylight autonomy
revealed that floor plates could…
Advisors/Committee Members: Konis, Kyle (Committee Chair), Carlson, Anders (Committee Member), Noble, Douglas (Committee Member), Lesak, John (Committee Member).
Subjects/Keywords: historic building; building stock; passive design; daylight autonomy; thermal autonomy; simulation; EnergyPlus; Radiance
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share





❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Becker, G. S. (2015). ctrl+z: exploring the effects of undoing retrofits to
pre-war buildings in Los Angeles. (Masters Thesis). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/610190/rec/1720
Chicago Manual of Style (16th Edition):
Becker, Geoffrey S. “ctrl+z: exploring the effects of undoing retrofits to
pre-war buildings in Los Angeles.” 2015. Masters Thesis, University of Southern California. Accessed March 07, 2021.
http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/610190/rec/1720.
MLA Handbook (7th Edition):
Becker, Geoffrey S. “ctrl+z: exploring the effects of undoing retrofits to
pre-war buildings in Los Angeles.” 2015. Web. 07 Mar 2021.
Vancouver:
Becker GS. ctrl+z: exploring the effects of undoing retrofits to
pre-war buildings in Los Angeles. [Internet] [Masters thesis]. University of Southern California; 2015. [cited 2021 Mar 07].
Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/610190/rec/1720.
Council of Science Editors:
Becker GS. ctrl+z: exploring the effects of undoing retrofits to
pre-war buildings in Los Angeles. [Masters Thesis]. University of Southern California; 2015. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll3/id/610190/rec/1720