The cold gas competition is BURPG's intro project that allowed new members to become familiar with the team's workflow of independent research, CAD modeling, and the iterative design process through a series of design reviews. The objective of this competition was to calculate, design, optimize and build a cold gas thruster while maximizing thrust and minimizing weight given a set of parameters such as minimum throat diameter and chamber pressure. 

First, I read Rocket Propulsion Elements to understand isentropic flow relations and basic nozzle design theory. Applying my newly gained knowledge, I set out to create a MATLAB script to calculate my nozzle exit area, my required mass flow rate, my thrust and ISP at sea level, and other required parameters for my design. 

I decided on creating a "converging, diverging bell nozzle" which is also known as a de Laval nozzle. The basis of this design is that I would be able to take the cold gas that enters the chamber and rapidly speed up the velocity of the gas by "choking the flow" with my nozzle throat. Soon, I developed my first nozzle named "Laminar Flow One." 

After a preliminary design review, I realized that my design faced issues such as interfacing and insufficient nozzle wall thickness according to FEA. To resolve these issues, I decided to make the nacelles for mounting significantly larger and increase the length of the nozzle to make it a 100% bell nozzle to increase thrust at the cost of increasing weight. Furthermore, I slightly increased the nozzle wall thickness to handle the expected pressures with a minimum FOS of 2. I decided to print my nozzle out with PLA since it would be significantly easier to create the contour that I wanted with a 3D printer. Unfortunately, I was not able to "hotfire" my nozzle on BURPG's cold gas test stand. However, I am making a strong push to eventually test my nozzle design on my personal cold gas thruster block.