General Atomics Internship
After completing my junior year of my undergraduate degree I spent my summer working for General Atomics. During the ten week program I completed various projects in design and analysis for the Avionics Chassis Department. As I was taught Solidworks in school I first had to teach myself Creo before completing design projects.
Design, Assembly, and Integration
One of these design projects was to assemble a daylight nose camera. I had to re-assemble a model with a new camera design and bracket and then complete an assembly drawing. Another project I worked on was to make a fan control design and integrate it into a full payload tray assembly. After finding a reasonable place in the CAD model to fit the fan controller, I made a rough model of the same dimensions out of paper and made sure my placement was appropriate in the actual Predator B payload tray. Next, I was tasked to make a design to fix a module that did not pass a drop test. The drop test resulted in a panel mount misalignment inside an oil heater controller module and the connections needed to make the module work became disconnected. In order to overcome this failure I designed brackets to hold the module in place. My last project was a cooling pipe design. I had to ensure the pipe was not too long or had too many bends to avoid losses, while also avoiding interferences with ignition lines that would heat the air. I made two designs and compared the pipes through loss analysis calculations.
Analysis
During my internship for General Atomics I also worked on analysis. One of my first projects was a condensation analysis. Condensation could occur if the outside air temperature was much cooler than the inside air temperature of an assembly. This moisture would then be a risk to the electrical components of the assembly. For the IR Camera I calculated the dew point temperature that would cause condensation for various relative humidity (RH) and internal and external temperatures using the Magnus formula. Then, after determining if condensation would occur, I calculated the mass of water using the ideal gas law. I concluded that even for the worst conditions the mass of condensed water was negligible and could be dried by addition of desiccant. Another analysis that I completed was a stress analysis on a heavy duty panel antenna. The antenna hung high in the air and could be subject to strong wind velocities that would stress it’s bolts. In order to initially analyze the risk I first completed hand calculations, noting that it was an eccentrically loaded bolted connection problem. Then I completed a more detailed FEA analysis. The hand calculations and FEA analysis matched within 5% - 15%. Finally, after looking over the bolt specifications I used the FEA analysis to calculate the maximum wind speed that the bolted connections could withstand.