3. Introduction...
Project Objectives
1)To analyze four simplified nozzle
geometries in a model rocket and
calculate their maximum thrust.
2) Compare the theoretical and
experimental thrust of these nozzles.
Choose the best nozzle based on our
data.
4. Introduction...
Which simplifications?
The Nozzle Configurations we modeled:
1)
2)
3)
4)
Orifice
Converging Nozzle
Diverging Nozzle
Converging-Diverging
(Click on links above to see the various
configurations)
5. Introduction...
Rocket Particulars
The type of rocket we modeled:
1) Solid Propellant / Core Burning
Core burning rockets burn propellant from the
“inside out.”
This is in comparison to endburning rockets which burn
propellant from the “bottom up.”
Graphic from: http://www.sewanee.edu/physics/SEMINARS/HTML%20Rowland/sld011.htm
11. FLUENT
Particular Settings
1)
2)
3)
4)
On all configurations the iterations
were run to a residual of 1e-3
Turbulent Flow (K-E model)
Variable Density
Used 2nd Order Equations to Calculate
Density / Pressure / Momentum
17. Literature
The preponderance of literature clearly shows
the Converging – Diverging Nozzle as the most
efficient nozzle design.
Diagrams like this
(right) are not
uncommon:
Graphic from: http://www.nakka-rocketry.net/lambda_p.html
20. Experimental Data
Experimental Setup Method #1
Method #1
In this case the nozzle
thrust was downward
onto the scale.
Before ignition, a thin
metal plate was placed
on top of the scale to
protect it from the
flame.
21. Experimental Data
Testing Using Method #1
For record keeping, a
camcorder was
zoomed up close to the
scale and recording.
Note the metal plate protecting the
plastic of the scale.
22. Experimental Data
Method #1 (Thrust Downward)
Set 1
(oz)
Set 2
(oz)
Converging
0.5
0.4
Diverging
0.25
dud
Regular Orifice
0.6
0.7
Converging - Diverging
n/a
n/a
Nozzle Type
23. Experimental Data
Experimental Setup Method #2
Method #2
In this case the
nozzle was
placed into a
hollow tube and
thrust was
directed
upward. Thus
the rocket
pushed onto
the scale.
24. Experimental Data
Testing Using Method #2
Note the
camcorder was
zoomed up
close to the
scale.
(Right) Movie of
ConvergingDiverging Run:
Click on Image
to Play
