Category Archives: Uncategorized

USS Alabama Battleship Memorial Park

The USS Alabama Battleship Memorial Park in Mobile, AL displays an interesting collection of WW2 ships and aircraft not normally seen. The collection includes several rare museum items. The park is well worth the visit.

The Battleship Memorial Park visit is contained in 3 parts:

USS Alabama (BB-60)

My visit operated under a slightly modified charter, as it was a sponsored program by the BSA and included an overnight “opportunity”. The ship is designed around three 16 inch gun turrets.

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TuskaUAV talk on Aerodynamics and Propulsion

As the advisor of the TuskaUAV group, I was asked to give a 30 minute chat to the student group on the topic of aerodynamics and propulsion with a special emphasis on small unmanned aerial vehicles. The four-up double sided handout is available below. The formal talk concluded with a Q/A session both during and after the meeting. Thanks for the opportunity!

[Book Review] Partial Differential Equations for Scientists and Engineers by Stanley J Farlow

Stanley Farlow’s textbook Partial Differential Equations for Scientists and Engineers is a reasonable introductory book for undergraduate and graduate students in the sciences and engineering. This book covers classical solution techniques, basic numerical methods, and -finally- the use of special techniques for solving non-trivial problems. This book is NOT acceptable for graduate students in mathematics, as can be seen directly in the title. Theory is briefly discussed, but the heart of the book is solving problems.

I taught a graduate course (GES 554, see here) for engineers with the book. ISBN-13: 978-0486676203


  • Reasonable coverage of classical methods
  • Very low cost ($12).
  • Discusses the physics of why terms appear in PDEs


  • Basic at best.
  • No formal mathematical proofs.
  • Only 1 section (Burger’s equ) discussing non-linear PDEs
  • Solutions in the back are often not correct
  • Topic order (especially for classification) is scattered.

Gulfstream GV / G550 CAD Model

Today, I created a CATIA CAD model of the Gulfstream GV / G550 aircraft. There are a few discrepancies in the details, especially with the windows and doors; however, the basic aircraft geometry is lofted from drawings.

Sharp aerospace engineers may question several of the fundamental design parameters and wonder about the airfoil selection (yes, supercritical, but GIII airfoils), surface quality (certainly not production quality), and purpose. It’s definitely not trivial to reverse engineer a CAD model from scratch, but it is doable for low to medium fidelity requirements. The CAD model is available here:

Articulated 4 Bar Mount Design

In this note, I will design an articulated 4 bar mount for a radar system using CATIA. The system needs to be designed and built rapidly for a VIP demonstration. Here’s the design:

First, the design requirements and needs:

  • Precise pointing requirements from nadir (straight down) to horizontal.
  • Mount on a boom lift / cherry-picker bucket
  • Separate two antennas of 30 pounds and 10 pounds by at least 2 meters with less than 1 deg of twist.
  • Designed, sourced, and built within a tight schedule

The articulated arm as designed by CATIA met the design goals with a commonly available actuator. The use of a CAD model allowed for tuning of the geometry and resulting kinematics.

Using the gearing ratio between the actuator and the output angle, conservation of power, and the measured actuator dynamics, I was able to analyze, simulate, and tune the dynamic/transient dynamics of motion of the system. This analysis allowed for a truly coupled actuator/mechanism design and ensured that my design remained feasible across the entire operational envelope.

Design drawings were created to construct the actuation arm.

The as-constructed articulated arm met the design requirements and when mounted on a boom-lift was successfully was used for a data collection experiment.

This articulated arm mechanism’s development shows the power of CAD with CATIA for rapid support of R&D projects. I was pleased.