Test Combustion Chamber for Jet Engine

thingiverse

Proof of concept model to see if we can sustain gas fueled (propane, methane) combustion inside ABS parts. **Note:** notice the inclination of the inner cylinder holes; airflow is meant to go from bottom side upwards. The final objective of this project is to attempt and 3d print a functional jet engine. Inspired by [Thalmano's Jet Engine](https://www.thingiverse.com/thing:241437) (demo model, runs on compressed air) and some working homemade metal designs by Mattis Berntsson: - [Homemade Jet Engine Plans](https://youtu.be/CmnibE_1Rzw) - [Homemade Axial Jet Engine - Test Runs](https://youtu.be/trcnd7qs-S8) Our first idea was to look for high temperature resistant materials and low temperature burning fuels. However, after some research we quickly found that there is a great temperature disparity between plastic resistance and combustion temperatures (surprise, surprise!). Also the availability of materials made us decide to go ahead with ABS and a readily available gas as fuel (like propane or natural gas). The project now hinges on our ability to keep the ABS cooled and this test chamber was designed for a first experiment to gather data regarding air cooling and combustion mixture manipulation to keep the chamber wall temperatures low. An ideia currently in development is the use of water to keep the ABS below it's Glass Transition Temperature ([105°C](https://help.matterhackers.com/article/109-what-material-should-i-use-in-a-high-temperature-environment)), based on the idea that lets you boil water on a paper box: as water boils, it keeps the temperature constant at 100°C and dissipates everything else via it's latent heat of vaporization. <hr> ### Dimension data: - Outer cylinder: - Height: 220mm. - Diameter: 120mm. - Thickness: 3mm. - Inner cylidner: - Height: 220mm. - Diameter: 74mm. - Thickness: 3mm. - Space between cylinders: 20mm. - Support fins: 4mm*220mm elipses. - Holes: - Made by intersecting inner cylinder with 5mm*6mm elliptical cylinders at 30° with vertical. - 4 layers of 16 alternating with 4 layers of 12 evenly distributed cylinders. Made with [Tinkercad](https://www.tinkercad.com/things/aoybfJ1xVrC). ### Other Materials Required - Gas source, valve, and injection hose. - Airflow generator (computer fan, air blower, adapted vacuum cleaner, ...). - Temperature sensor (thermocouple) - Fire safety equipment. ### Test Guidelines 1. Print piece. 2. Setup gas hose with adjustable valve. 3. Setup airflow generator (computer fan, air blower...). 4. Setup temperature sensor (thermocouple). 5. Prepare fire safety equipment. 6. Ignite. 7. Attempt to minimize combustion temperature. 8. Analyze chamber damage.