MAE 284 – COMBUSTION TAKE-HOME MIDTERM EXAM
Prof. C. A. Garris Due: Wednesday, November 1, 2023 (in-class)
PROBLEM NO. 1:
2 2 2
the EQUILIBRIUM composition for the reaction:
1
2
:
1 and 2000 ; 101,325 Pa
the EQUILIBRIUM COMPOCALCULATE
ICONS DER
oH
O
H O H O
where
NZ T K P
N
+
= = = =

2 2 2, , ,
SITION, H O H Oχ χ χ
PROBLEM NO. 2:
combustion of a
stoichiometric mixture of n-Octane - Air mixture.
Assume:
Initial Conditions: 298 ; 1
No dissociation (complete combustion)
Constant sp
CONSTANT VOLUMECONSIDER
o
init initT K P atm= =

 ecific heats evaluated at 1,200 .
1. Adiabatic Flame Temperature, , in .
2. Final Pressure, , in .
3. Using software of APPENDIX F, determine and
when dissociation o
DETERMINE:
o
o
ad
final
ad final
K
T K
P atm
T P
ccurs and compare your results with 1 & 2.
PROBLEM NO. 3:
an industrial furnace which operates at atmospheric pressure, 1 atm, and
uses preheated air to improve its fuel efficiency. The following are some operating
parameters of the furnace:
CONSIDER
18; Preheated air temperature = 800 ; 450
Adiabatic Flame Temperature,
the following thermodynamic properties:
300 ;
:
ASSUME
o oair
air preheat fuel
fuel
adiab
o
ref
mA T K T KF m
T
T K
DETERMINE
−= = = =
→
=


, , ,
9
, , ,
29
3500 ; 1200
0 ; 1.16 19
fuel air prod
p fuel p air p prodo o
o o o
f air f prod f fuel
kgMW MW MW kmole
J Jc c c
kg K kg K
Jh h h x
kmol
= = =
= = =
− −
= = =
NOTES:
1. Show all work.
2. For computer calculations, show input and output files.
3. This exam is an individual effort. No communication with anyone, inside or outside the
class, concerning the solution of the problems is permitted.
4. The exam is open book, open notes.
5. Professional appearance is expected.