MAE 321 – Applied Thermodynamics
HW 8 Assignment
November 20, 2015
The homework is due Monday December 7, 2015. Each problem is worth the points indicated. I
encourage you to work in small groups to learn this material. However, copying of the solution
from another is not acceptable.
1. For combustion of stoichiometric air with carbon monoxide, determine (a) the air-fuel ratio, (b)
equivalence ratio, and (c) dew point temperature of the exhaust. Assume complete combustion and a total
pressure of 1 atm in the exhaust. (20 points)
2. For combustion of propane in stoichiometric air (both entering the combustor at 1 atm and 25 °C),
determine (a) the enthalpy of combustion, (b) the lower heating value, and (c) compare the value in Table
A-27 to your value. (25 points)
3. Methane is burned with air. The exhaust products are measured on a dry volume basis to be 9.7% CO2,
0.5% CO, 2.95% O2, and balance of N2. Determine (a) the air-to-fuel ratio (mass based), (b) the percent
theoretical air (%), (c) the percent excess air (%), and (d) exhaust dew point (°C) if the exhaust is at 1
atm. (25 points)
4. A dried cow manure fuel is proposed as a source of energy conversion. A mass analysis of this fuel
sample is 42.7% carbon (C), 5.5% hydrogen (H), 31.3% oxygen (O), 2.4% nitrogen (N), 0.3% sulfur (S),
and the balance as non-combustible ash. If this fuel is burned in 150% theoretical air, determine (a) the
balanced reaction equation and (b) the air-to-fuel ratio on a mass basis. (30 points)
5. Calculate the adiabatic flame temperature of acetylene combusting with stoichiometric air. The
acetylene enters the combustor at 25 °C, 1 atm and the air enter a combustor at steady state at 17 °C, 1
atm; the products of combustion exit at 1 atm. (100 Points)
6. Provide a detailed assessment of using the manure in problem 4 in place of fossil-based fuels such as
coal or natural gas for large scale energy conversion needs. A minimum one page, 1 ½ spacing, 12 point
font, with 1” margins is required to receive full credit. References should be included where needed and
would be in addition to the minimum one page requirement. You need to address the basic
thermodynamic aspects along with societal impact of using this energy source. (50 Points)
Suggested Book Problems to Review:
These problems will not be collected, but are suggested as a review.
Chapter 15: 5, 14, 17, 21, 29, 35, 39, 47, 49, 58, 62, 65, 72, 74, 79, 83

MAE 321 – Applied Thermodynamics
HW 8 Assignment
November 20, 2015
The homework is due Monday December 7, 2015. Each problem is worth the points indicated. I
encourage you to work in small groups to learn this material. However, copying of the solution
from another is not acceptable.
1. For combustion of stoichiometric air with carbon monoxide, determine (a) the air-fuel ratio, (b)
equivalence ratio, and (c) dew point temperature of the exhaust. Assume complete combustion and a total
pressure of 1 atm in the exhaust. (20 points)
2. For combustion of propane in stoichiometric air (both entering the combustor at 1 atm and 25 °C),
determine (a) the enthalpy of combustion, (b) the lower heating value, and (c) compare the value in Table
A-27 to your value. (25 points)
3. Methane is burned with air. The exhaust products are measured on a dry volume basis to be 9.7% CO2,
0.5% CO, 2.95% O2, and balance of N2. Determine (a) the air-to-fuel ratio (mass based), (b) the percent
theoretical air (%), (c) the percent excess air (%), and (d) exhaust dew point (°C) if the exhaust is at 1
atm. (25 points)
4. A dried cow manure fuel is proposed as a source of energy conversion. A mass analysis of this fuel
sample is 42.7% carbon (C), 5.5% hydrogen (H), 31.3% oxygen (O), 2.4% nitrogen (N), 0.3% sulfur (S),
and the balance as non-combustible ash. If this fuel is burned in 150% theoretical air, determine (a) the
balanced reaction equation and (b) the air-to-fuel ratio on a mass basis. (30 points)
5. Calculate the adiabatic flame temperature of acetylene combusting with stoichiometric air. The
acetylene enters the combustor at 25 °C, 1 atm and the air enter a combustor at steady state at 17 °C, 1
atm; the products of combustion exit at 1 atm. (100 Points)
6. Provide a detailed assessment of using the manure in problem 4 in place of fossil-based fuels such as
coal or natural gas for large scale energy conversion needs. A minimum one page, 1 ½ spacing, 12 point
font, with 1” margins is required to receive full credit. References should be included where needed and
would be in addition to the minimum one page requirement. You need to address the basic
thermodynamic aspects along with societal impact of using this energy source. (50 Points)
Suggested Book Problems to Review:
These problems will not be collected, but are suggested as a review.
Chapter 15: 5, 14, 17, 21, 29, 35, 39, 47, 49, 58, 62, 65, 72, 74, 79, 83