Engineering Portfolio
by Pablo Villa
I have developed a well-rounded, multi-disciplinary engineering background with a strong foundation in engineering design, structures, thermodynamics, and controls in my 4 years at Purdue University studying Aerospace Engineering. I bring significant demonstrated experience with designing, building, and flying unmanned aerial vehicles (UAVs) under 55lbs as well as utilizing camera & gimbal systems ranging from tiny GoPros to movie-grade cinema cameras, among many other skills I have picked up on through personal interests, research, and an internal motivation to get up every day and do something to help me become a great engineer.
​
Most recently as an undergraduate research assistant, I have been in charge of creating and testing the camera system for Purdue's zero-gravity cryogenic bubbles phenomena experiment, dubbed "Cryobubbles" by the team, under the guidance of Professor Steven Collicott. My camera system involves mirrors to capture visual data in tight spaces as well as a power system and HDMI multi-view interface to monitor all cameras in-flight, and has been redesigned from the previous system to successfully capture data in a significantly greater resolution and with monitoring capabilities that were previously unreliable. The experiment is currently set to fly on G-Force One out of Fort Lauderdale on April 22nd and April 23rd, 2024, and will be paramount in providing invaluable data for countless future space missions across the globe that could benefit from vent-less cryogenic storage systems.
UNDERGRADUATE RESEARCH
Cryobubbles | Cryogenic Bubble Formation Phenomena Experiment - Building on NASA's ZBOT Observations
Purdue's 'Cryobubbles' experiment was created to understand an unexpected bubble formation phenomenon during a tank-pressure control strategy test of NASA’s Zero Boil-off Tank (ZBOT) on the International Space Station. Thanks to their grant, our experiment has been designed by undergraduate students to test hypotheses on a parabolic flight as to the cause of the phenomenon.
Overall Experiment
Front view of LN2 test chamber with polyisocyanurate insulation
One of 8 test vessels, made of acrylic. Screen can be seen inside
Test vessels and interior plumbing of LN2 test chamber
Window Stack-up
Our initial window stack-up for testing thermal fracture is installed, with O-rings inside seats machined into flanges.
The first and second window flanges can be seen to be frosted during a thermal fracture test I helped perform.
The recent implementation of gaskets as opposed to O-rings, which caused failure, is seen above before actual installation.
A recent "soapy water" test was conducted to check for leaks with the new addition of gaskets.
Camera System
Mirror and camera hardware (left and right respectively) are shown for the most complex placement of the 4 cameras due to a tight space.
Mirror being used to view the 2 vessels from a longer distance creating a more linear image with a longer 10mm lens rather than a wider 4.5mm lens, which was impossible to install due to space restrictions.
The GoPro's view through the mirror placed at a 45 degree angle to the camera's line of view.
Custom Solar UAV | 2.1 Meter Wingspan, 4 Engines
This solar UAV project was developed over the summer of 2023 for a research study at Purdue University under Professor Richard Voyles. This research was focused on analyzing the effects of attaching solar cells in various configurations on the top and bottom surfaces of a UAV to improve the aircraft's efficiency and performance.
​
The scope of my research responsibilities was to develop the platform and ensure all systems and items were working through testing.
​
Development included: parts selection, design , fabrication, assembly, tuning and autonomous flight calibration. I tested the solar power system on its own and the UAV platform on its own. The full system test will be conducted by PhD students based on the solar UAV study hypothesis from the original paper.
​
One of the biggest challenges was being able to carefully solder and attach the delicate solar panels to the wing, which previous students were unsuccessful with but myself and a graduate assistant were able to successfully install the solar panels on the wing and measure their voltage across both wings connected.
Overall CAD
Full Wing With Solar Cells Installed
2D Layout for Laser Cutting Foam
Engine Cells
Pictured above is one of four engine cells with a mounted motor and propeller as well as electronics installed inside. Vents were added to allow for passive cooling during flight to prevent system failures.
Pictured above is the right foam wing assembled and with the 3D-printed ribs and carbon fiber spars. The wing is wired wing a custom connector for quick attachment in the field without fiddling with 6 different PWM cables.
Flight Testing
Conducted successful flight tests with a maximum continuous flight time of almost 1 hour. All flight data was recorded on the UAV and on the ground station via wireless data telemetry. Flights were conducted using waypoint GPS navigation and onboard fly-by-wire technology which I programmed using Q-Ground Control Software.
Shown on the right is a video of my research partner, Chin, helping us release the aircraft with a running start in order to avoid the need for landing gear which added weight and complexity to the aircraft, and was not necessary for the scope of the project.
​
I can be seen in the blue and white shirt controlling the aircraft, in the process of taking it up to a good cruising altitude to perform autonomous mode testing.
PERSONAL PROJECTS
X8 Heavy-Lift Octo-copter | 8 Engines, Coaxial Formation
This is another work in progress project that I have been developing since roughly my junior year of high school. The ultimate purpose is being able to lift a heavy and high-value cinema camera & gimbal payloads for the use of aerial footage for video projects. This required cohesive programming, redundancy, and powerful energy distribution methods.
Admittedly, this is my worst project in terms of proper documentation, and spans many years. Many of the original pictures I took during manufacturing were lost with a damaged hard drive in 2019, or sit on an almost unusable computer in my Connecticut hometown of New Canaan. Much like my Nova H210 UAV, it is currently sitting in my parents' basement waiting to be improved on when I get the chance to go home again, as I don't get to go home often. The pictures below were taken in that basement.
Electronics Stack-up
Side view of all electronics in the drone. Bottom layer (at the level of the arms) contains electronic speed controllers, solid copper power distribution board (PDB) and associated power and signal cabling. The thicker layer above it contains the flight controller, receiver, signal transducer, and associated cabling. At the top the two 6-cell LiPo batteries can be seen.
Original 2017 Notebook Sketch / Design
Nova H-210 | 12-ft Wingspan, Tri-fuselage RC Aircraft
This was a passion project that I began back in my sophomore year of high school as an independent study, and have been working on it ever since. It features a triple fuselage and long wing design based on the Rutan Voyager, but I meant to create more of a "reconaissance" type aircraft that could cruise at low speeds and be as realistic as possible in terms of capabilities, such as retractable landing gear, differential thrust, flaps, and steerable front gear for taxiing.
My remote-control aircraft hobby has always been driven by an inexplicable desire to take off, fly, and land like a real aircraft and with as much accuracy as possible, including advanced flight concepts like crabbing into cross-winds for landing. One of my ultimate goals with my custom RC aircraft is to one day expand on this design or create a completely new one to create a first-person-view aircraft with a cockpit camera that can rotate with the movements of my headset through which I will view the flight, and do so in the beautiful deserts of the west.
FIRST DESIGN: Pictured is a sketch I created of this aircraft inspired by the RM76 Voyager (pictured on right) in November 2016. I did not begin to create the real model until roughly 2018.
INSPIRATION: Rutan Model 76 Voyager: First aircraft to fly around the world without stopping or refueling, piloted by Dick Rutan and Jeana Yeage.
Pictured above is myself standing next to my near-completed aircraft, during an initial test on my high school track (left) and on the workbench a week or so earlier (right).
Middle fuselage
Pictured left is my laser-cut baseplate designed in CorelDraw X7 for the middle fuselage, and on the right is the fuselage once I had the majority of the wiring set up and organized. The carbon fiber support system to help strengthen the fuselage against torquing, which was not part of the original design, is seen on the bottom. Wiring from the wings and "fuel" fuselages was brought through the carbon fiber tubes to the main fuselage to avoid moving wires through the delicate wings.
Pictured above is the back of the left and right fuselages holding the left and right retracts.
Wing Box
Middle Wing Structure
Wings and Wingtips
Lessons Learned
Sizing of all aspects of an aircraft is crucial, which I did not fully know as a high school sophomore when I began the project.
​
Consideration of all internal forces that could act on an airplane, from its own weight and structure, is extremely important.
​
Adding motors for fun or for "more thrust" without justification can cripple the performance of the aircraft.
​
Careful placement of landing gear, rather than only considering if it will tip over or not, should be done. In my design, I should have placed it closer to the the trailing edges as it would experience a lesser moment and impact upon landing.
Future Personal Project | VTOL Craft