Updated 11/17:
| Specification | Value |
|---|---|
| Contraction Area Ratio | 8.73 |
Chamber Diameter | 3.25 in (minimum) |
| Throat Diameter | 1.1 in (minimum) |
Characteristic Length | 57.8 in |
Chamber Length | 6 in |
Contraction Angle | 30 deg |
| Expansion Angle | 15 deg |
| Exit Diameter | 2.504 in |
| Ideal Exit Pressure | 14.04 psi |
Expansion Ratio | 5.18 |
Chamber Pressure | 445 psi |
Chamber Temperature | 3023 K (stagnation) |
| Mass Flow | 1.18 kg/s |
| Exit Mach Number | 2.7 |
| OF Mixture Ratio | 4.15 |
| Specific Impulse | 234s |
| Average Thrust | 2600 N |
- Contraction ratio issue solved. Now have chosen maximum acceptable value of 10
- nozzle sized ~1.5 mm less to account for expected 0.1 mm/s erosion
- exit area also sized down to match nozzle
To do:
- Thermal analysis
- FEA
- Thermocouple
References:
https://ocw.mit.edu/courses/16-512-rocket-propulsion-fall-2005/resources/lecture_3/ (Exit pressure)
https://www.eucass.eu/doi/EUCASS2017-474.pdf (L*, contraction ratio)
https://ntrs.nasa.gov/api/citations/19710019929/downloads/19710019929.pdf (angles, general)
https://yang.gatech.edu/publications/Journal/JPP%20(2008,%20Thakre).pdf(graphite)