Type of Document Dissertation Author Tyll, Jason Scott Author's Email Address email@example.com URN etd-63097-162653 Title CONCURRENT AERODYNAMIC SHAPE / COST DESIGN OF MAGNETIC LEVITATION VEHICLES USING MULTIDISCIPLINARY DESIGN OPTIMIZATION TECHNIQUES Degree PhD Department Aerospace and Ocean Engineering Advisory Committee
Advisor Name Title Deisenroth, Michael P. Marchman, James F. III Mason, William H. Mook, Dean T. Schetz, Joseph A. Committee Chair Keywords
- ground effect aerodynamics
Date of Defense 1997-07-24 Availability restricted AbstractA multidisciplinary design optimization (MDO) methodology is developed to link
the aerodynamic shape design to the system costs for
magnetically levitated (MAGLEV) vehicles.
These railed vehicles can cruise at speeds approaching that of short
haul aircraft and travel just inches from a guideway.
They are slated for high speed intercity service of up to 500
miles in length and would compete with air shuttle services.
The realization of this technology hinges upon economic viability which is
the impetus for the design methodology presented here.
This methodology involves models for the aerodynamics, structural
weight, direct operating cost, acquisition cost, and life cycle cost
and utilizes the DOT optimization software.
Optimizations are performed using sequential quadratic programming
for a 5 design variable problem.
This problem is reformulated using
7 design variables to overcome problems due to non-smooth design space.
The reformulation of the problem provides a smoother design space which
is navigable by calculus based optimizers.
The MDO methodology proves to be a useful tool for the design of MAGLEV
The optimizations show significant and sensible differences between designing
for minimum life cycle cost and other figures of merit.
The optimizations also show a need for a more sensitive acquisition cost model
which is not based simply on weight engineering.
As a part of the design methodology, a low-order aerodynamics model is
developed for the prediction of 2-D,
ground effect flow over bluff bodies.
The model employs a continuous vortex sheet to model the solid surface,
discrete vortices to model the shed wake, the Stratford Criterion to determine
the location of the turbulent separation, and the vorticity conservation
condition to determine the strength of the shed vorticity.
The continuous vortex sheet better matches the mechanics of the flow
than discrete singularities and therefore better predicts the ground effect
The predictions compare well with higher-order computational methods and
A 3-D extension to this model is investigated, although no 3-D design
optimizations are performed.
NOTE: An updated copy of this ETD was added on 05/29/2013.
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