10/13 27
Updated specifications:
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| Specification | Value |
|---|---|
| Contraciton Area Ratio | 9.66 |
Chamber Diameter |
| 3.5 in |
...
| Throat Diamter | 1.127 in |
Characteristic Length | 64 in |
Chamber Length | 6 in |
Contraction Angle | 30 deg |
| Expansion Angle | 15 deg |
| Exit Diameter | 2.54 in |
| Exit Pressure | 14.12 psi |
Chamber Pressure | 460 psi |
| Mass Flow | 1.2 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) diameter of 1.1326 in
- Mass flow is 1.2 kg
- Chamber pressure of 460 (do calculations with 10% less)
- Exit pressure of 97329.71 Pa
- 30 deg contraction and 15 deg expansion angles
- L* is 63-64 with a chamber length of 6 in
To do:
- Thermal analysis
- CAD update (round/adjust values)
- 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)
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https://ntrs.nasa.gov/api/citations/19710019929/downloads/19710019929.pdf (angles, general)
https://yang.gatech.edu/publications/Journal/JPP%20(2008,%20Thakre).pdf(graphite)