1. By: Eric Nauman
Pat Johnson
John Mauk
Yimu Yang

2.  History of the Otto engine
 Assumptions
 Energy Balance and Calculations
 New Technologies/Alternative Fuels

3. Nicolaus Otto was born in Germany in 1832
The Otto engine was first made in 1876
He obtained total of 25 patents
Contrary to belief Alphonse Eugène Beau de Rochas
made the first “Otto” cycle

4. -Otto cycle
-Closed System
-Assumed as an ideal Otto Cycle
-Kinetic Energy and Potential Energy
effects negligible
-Reversible

5. Energy Balance
Q+W = mdot[ΔU + ΔKE + ΔPE]
ΔKE=ΔPE=0
Step 1: Intake Stroke
Air/Fuel mixture is drawn into
the chamber to be ignited

6. Step 1-2: Adiabatic Compression
Q=0 (adiabatic) W = ΔU = U 2 - U1

7. Step 2-3: Isochoric Heating
W=0 (Const Vol) Q = ΔU = U 3 – U2
Heat is added from combustion

8. 

9. 

10.  Calculating Efficiency
η = Wnet/Q23
~35%-40% efficient
η = 1 – r (1/r)^γ - 1
P4/P1 = P3/P2 = r = compression ratio
γ = Cp/Cv

11. 

12.  “ECO-” Portion9:
How does it work?
1. Uses EGR (Exhaust Gas Recirculation)
2. EG cooled after combustion
3. These inerts take up dead space in cylinder, allowing for
less of an intake of “fresh” air (oxygen).
4. Less intake of “fresh” causes less fuel to be injected by
ECU
5. Kept at stoichiometric ratio of 14.1-1 (A/F), with less fuel
used.
6. Causes 19-20% less fuel to be burned.

13. 

14. Ethanol: CH3CH2OH + 3 O2  2CO2 + 3 H2O
Butanol: C4H9OH + 6 O2  4CO2 + 5 H2O
Ethanol ΔHc (LHV) = 19.6 MJ/L
Butanol ΔHc (LHV) = 29.2 MJ/L
Gasoline ΔHc (LHV) = 32 MJ/L
Butanol Energy Density = 29% higher than EtOH
and 8.8% lower than Gasoline

15.  References
 1 Chemical Economics Handbook Report Plasticizer Alcohols, SRI International, May
2002, pages 8- 9 and 27.
 2 Thaddeus Chukwuemeka Ezeji, Nasib Qureshi and Hans Peter Blaschek, 2007.
Bioproduction of Butanol from Biomass: From Genes to Bioreactors, Current Opinion on
Biotechnology 18:220–
227, http://ddr.nal.usda.gov/bitstream/10113/14428/1/IND44052939.pdf, retrieved 12 Apr.
2012.
 3 1-Butanol as a Gasoline Blending Bio-Component, BP Mobile Sources Technical Review
Subcommittee, March
28, 2007, www.epa.gov/air/caaac/mstrs/March2007/Wolf.pdf, retrieved 12 Apr. 2012.
 4 The Biobutanol Advantage, Butamax Advanced Fuels LLC, http://www.butamax.com/the-
biobutanol-advantage.ashx, retrieved 12 Apr. 2012.
 5Smith, J.M., Van Ness, H.C., Abbott, M.M., Introduction to Chemical Engineering
Thermodynamics, New York: McGraw-Hill 2005.
 6 Wikipedia contributors. "Butanol fuel." Wikipedia, The Free Encyclopedia. Wikipedia, The
Free Encyclopedia, 27 Mar. 2012. Web. Retrieved 12 Apr. 2012
 7Wikipedia contributors. "Otto cycle." Wikipedia, The Free Encyclopedia. Wikipedia, The
Free Encyclopedia, 28 Mar. 2012. Web. 12 Apr. 2012.
 Good diversity of references.
 8 www.mazda.com/mazdaspirit/skyactiv/Cached
 9hpc4energy.org/hpc-road-map/success.../ford-ecoboost-technology/