1. Ricky Hinton February 21st, 2008 Propulsion Group CAD group Updated Altitude vs. Pressure Code and Nozzle CAD
AAE 450 Spring 2008

2. Updated MATLAB Code: Solve for Altitude at Optimum Thrust
Input from Propulsion code:
Chamber Pressure
Pressure Ratio (exit to chamber)
Output
Solves for the exit pressure
Pe = Pa at optimum thrust
Plugs this into Altitude equation and solves for altitude
Test Cases for some historical engines
F-1 (Saturn V stage 1)
J-2 (Saturn V stage 2-3)
Vanguard
Sample 1: Pc = 2.1 Mpa (300 psi)
Sample 2: Pc = 0.86 Mpa (125 psi)
ε = 15, 20 respectively (γ = 1.2)
Engine Pc
Pe/Pc
Optimum Altitude
F-1
7 Mpa
6.40 km
J-2
3 Mpa
19.63 km
Vanguard
4.25 Mpa -
Sample 1
2.1 Mpa
15.97 km
Sample 2
0.86 Mpa
26.35 km
AAE 450 Spring 2008

3. CAD of Nozzle Bell Nozzle shape CAD model Specifications
80% Bell contour
Gives an exit angle of 8.5°
Reduces divergence loss at exit
Contour design from AAE 439
CAD model
Entire model is based off of the diameter at the exit.
Inputs:
Outside Diameter
Expansion Ratio
Nozzle Thickness
Model is dynamic if these parameters are changed
Specifications
Max Exit Diameter (D = 2 m)
Expansion Ratio (ε = 15)
Nozzle Thickness (t = 2 cm)

4. Future Work More CAD work
Integrate Altitude code for trajectory when needed
Test Facilities
AAE 450 Spring 2008

5. 4-way view of nozzle

6. View of the throat ( ε = 15 )

7. References
Pressure Altitude. Wikepedia.org. Last modified on 24 November 2007
AAE 439 Notes manual. Provided by professor Hrbud in Fall Nozzle design pages Saturn V specifications pages 3.55 – 3.57
Pressure vs. Altitude Relationships, S.E. Van Bramer 1/18/
AAE 450 Spring 2008