Papers I've Written for School

These are some academic papers I've written for school, all for Aerospace Engineering courses. Although none of these are genuine research, nor were any published in journals, I have encountered an occasional proceedings or business publication that cites the web version of these papers.

Searching for Lyapunov Functions using Genetic Progamming (PDF Version)

Here, I present genetic programming as a possible general method for finding Lyapunov functions. (Lyapunov functions are functions by which one can prove the stability of a nonlinear dynamic system.) This paper describes genetic programming, and how it can be used to find Lyapunov functions. This paper demonstrates that genetic programming is at least worth a better look. I now realize that there is a grave oversight in this method as I've implemented it, although the fix is obvious. [AOE 5984, Nonlinear Control, Virginia Tech]

Self-Tuning Control with Control Allocation (PDF Version)

This investigates adaptive control: namely self-tuning control which uses parameter identification to determine control effectiveness for use in control allocation. This project is one of the main reasons I decided to abandon my research on on-line parameter identification. After doing this work, I no longer think on-line parameter identification is that important. [ECE 6414, Adaptive Control, Virginia Tech]

A Discussion of Methods of Real-Time Airplane Flight Simulation (PDF Version, slightly modified from what I turned in)

This what the scholarly paper which was a part of my Master's Degree requirements. There are some annoying errors in it, but it's mostly quite detailed and accurate. It describes mathematics and computer implementation of flight simulation.

Composite V-22 Blade Design

Documents my unsuccessful attempt to design a V-22 rotor blade whose shape adapts to the flight condition (hover or propeller) using anisotropic effects of fiber-reinforced composites. Because rotor speed, and thus the centrifugal force, is much higher in hover mode, I wanted to use the extra force to twist the blade into an optimal shape. [Aerospace 597I: Behavior of Advanced Structures, Penn State]

Helicopter Dynamic Stability

In this paper, I do an analysis of helicopter dynamic modes. I am a little amazed that I managed this one, and I think my professor was, too. There's some really advanced stuff in there. As for the results, I doubt their accuracy. They look quasi-reasonable, but I suspect there was a mistake lurking in my code. (Incidentally, although I had to have put at least 30 hours into this project, I whistled through the whole thing. Dynamics just interests me.) [Aerospace 504: V/STOL Aerodynamics, Penn State]

Boundaray Layers

A brief explanation of how boundary layers can really simplify the complicated incompressible Navier-Stokes equations of fluid dynamics. [Aerospace 508: Fundamentals of Fluid Dynamics, Penn State]

The Hodograph Transformation

I describe the hodograph transformation, which is an interesting analytical technique whereby certain nonlinear equations in aerodynamics can be transformed into linear equations. [Aerospace 597D: Topics in Applied Aerodynamics, Penn State]

Project Asterius: Mission to Europa

Here is a report I wrote with my spacecraft design team: Amy Briggs, Becky Carver, Patrick Morinelli, Brian Sarsfield, and Mark Newey. It descibes our design for a Europa Lander. We all learned a lot, and had a lot fun, but our design methodology was utterly terrible. I can't bring myself to read the report any more. [Aerospace 402B: Spacecraft Design, Penn State]