ME 10.412 / ME 10.512
Rocket Propulsion
Week 6
Thermochemical Rocket Calculations
Class Notes - Page: 1
Text: Sutton Ch. 5
Homework Assignment
1. NASA 1 kW Arcjet. For a NASA 1 kW arcjet operating on
hydrazine (N2H4), calculate the performance as a function of average
chamber temperature, Tc. Specifically, given the following
parameters:
Pc = 50 psia
Pa = 0.2 Torr
Ae/At = 150
dt = 0.64 mm
Generate the following plots using the NASA CEA Code:
a. Plot all equilibrium species mole fractions as a function of chamber temperature (1000 < T c < 10,000 K)
b. Plot C* vs. chamber temperature (1000 < T c < 10,000 K)
c. Plot  vs. chamber temperature (1000 < T c < 10,000 K)
d. Plot Average MW vs. chamber temperature (1000 < T c < 10,000 K)
2. Hybrid Rocket Motor Design Project. Using the NASA CEA Code, generate the following plots for an
HTPB/GOX hybrid rocket motor:
a. Tc as a function of O/F ratio.
b.  as a function of O/F ratio.
c. Average MW of chamber products vs. O/F ratio.
d. C* vs. O/F ratio
e. All equilibrium species mole fractions vs. O/F ratio.
Assume Pc = 150 psia. Also, note that HTPB is not in the NASA database. To use it as a fuel, you have
to input the heat of formation and chemical formula in the reactant section of the .inp file as follows:
name HTPB C 7.337 H 10.982 O .058 wt%=100
h,cal=-2970.00 t(k)=298.15
GOX
solid fuel