10/27
Updated specifications:
| Specification | Value |
|---|---|
| Contraction Area Ratio | 8.085 |
Chamber Diameter | 3.25 in (min) |
| Throat Diameter | 1.143 in (min) |
Characteristic Length | 63 in |
Chamber Length | 6 in |
Contraction Angle | 30 deg |
| Expansion Angle | 15 deg |
| Exit Diameter | 2.576 in |
| Exit Pressure | 14.12 psi |
Chamber Pressure | 460 psi |
| Mass Flow | 1.22 kg/s |
| Exit Mach Number | 2.723 |
- Contraction ratio issue solved. Now have chosen maximum acceptable value of 10
- Exit pressure is 97329.71 Pa, ideal calculations, see if matches RPA
- nozzle sized 1.5 mm less to account for expected 0.1 mm/s erosion
- exit area also sized down to match nozzle (with slight round up)
To do:
- Thermal analysis
- Graphite and phenolic erosion modeling
- O-ring sizing
- Slides
References:
https://ocw-mit-edu.ezproxyberklee.flo.org/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)