University Review (Hatim)
- 1. PERFORMANCE ANALYSIS OF ROCKET NOZZLE USING CFD BY HATIM S R 31709114044 GUIDE Mr. K. Arun (Ph. D)
- 2. AIM • Comparison of nozzle configurations across different altitudes • Exhaust gas flows will be studied using velocity contours • Specific Impulses will be calculated
- 3. NOZZLE CONFIGURATIONS •3 nozzle configurations: 1. Ideal Nozzle 2. 85% Bell Nozzle 3. 70% Bell Nozzle
- 5. OPERATING CONDITIONS • Fluid – Air • Nozzle Material – Titanium • Chamber Pressure – 100 psia (or) 7.09275 bar • Temperature – 500 K
- 6. OPERATING CONDITIONS • Ambient pressure will be varied • 4 different altitudes 1. Sea level – 1.01325 bar 2. 5000m – 0.540 bar 3. 10000m – 0.264 bar 4. 20000m – 0.055 bar
- 7. CFD PARAMETERS • Pressure-Coupled solver • Spalart-Allmaras Turbulence Model (used primarily in Aerospace application) • Air – Ideal Gas Density
- 8. BOUNDARY CONDITIONS •Pressure Inlet – Combustion Chamber •Pressure Farfield – Atmosphere
- 9. GEOMETRY OF IDEAL NOZZLE
- 10. MESH OF IDEAL NOZZLE
- 11. GEOMETRY OF 85% BELL NOZZLE
- 12. MESH OF 85% BELL NOZZLE
- 13. GEOMETRY OF 70% BELL NOZZLE
- 14. MESH OF 70% BELL NOZZLE
- 15. METHODOLOGY • Input: 1. Pressure: 100 psia or 7.09275 bar 2. Temperature: 500 K 3. Ambient Pressure • Output: 1. Velocity Contour 2. Specific Impulse
- 16. Velocity Contour of Ideal Nozzle • Sea Level - Ambient Pressure: 1.01325 bar • Nozzle is in overexpanded state, hence shocks are present
- 17. Velocity Contour of 85% Bell Nozzle • Sea Level - Ambient Pressure: 1.01325 bar • Nozzle is in overexpanded state, hence shocks are present
- 18. Velocity Contour of 70% Bell Nozzle • Sea Level - Ambient Pressure: 1.01325 bar • Nozzle is in overexpanded state, hence shocks are present • Contours show a drastic decrease in velocity
- 19. Velocity Contour of Ideal Nozzle • 5000m - Ambient Pressure: 0.540 bar • Nozzle is still in overexpanded state, but the shocks are said to have ‘progressed’ downstream of nozzle
- 20. Velocity Contour of 85% Bell Nozzle • 5000m - Ambient Pressure: 0.540 bar • Nozzle is operating at design condition as parabolic contour has decreased the exit pressure to ambient pressure
- 21. Velocity Contour of 70% Bell Nozzle • 5000m - Ambient Pressure: 0.540 bar • Nozzle is still in overexpanded state & shocks converge after a small distance showing that the thrust generated is very low
- 22. Velocity Contour of Ideal Nozzle • 10000m - Ambient Pressure: 0.264 bar • Nozzle is operating at design condition as isentropic expansion has decreased the exit pressure to ambient pressure and therefore no shocks are present
- 23. Velocity Contour of 85% Bell Nozzle • 10000m - Ambient Pressure: 0.264 bar • Nozzle is still operating at design condition because of the parabolic contour & therefore no shocks are present
- 24. Velocity Contour of 70% Bell Nozzle • 10000m - Ambient Pressure: 0.264 bar • Nozzle is operating at design condition and therefore no shocks are present
- 25. Velocity Contour of Ideal Nozzle • 20000m - Ambient Pressure: 0.055 bar • Nozzle is operating at underexpanded state and exhaust gas flow expands majorly outside of the nozzle • The flow bends around the nozzle lip
- 26. Velocity Contour of 85% Bell Nozzle • 20000m - Ambient Pressure: 0.055 bar • Nozzle is operating at underexpanded state and exhaust gas flow expands majorly outside of the nozzle • The flow bends around the nozzle lip
- 27. Velocity Contour of 70% Bell Nozzle • 20000m - Ambient Pressure: 0.055 bar • Nozzle is operating at underexpanded state and exhaust gas flow expands majorly outside of the nozzle • The flow bends around the nozzle lip
- 28. Specific Impulse
- 29. Conclusion • Ideal Nozzle has high specific impulse but increased length leads to higher inert mass & area of cooling • 85% Bell Nozzle has a good balance between specific impulse & nozzle weight reduction and also operates efficiently over a wider range of ambient pressures • 70% Bell Nozzle has very low specific impulse • Therefore 85% Bell Nozzle is suggested to be used as nozzle configuration in industry