1. COMBUSTION TA : Donggi Lee PROF. SEUNG WOOK BAEK
DEPARTMENT OF AEROSPACE ENGINEERING, KAIST, IN KOREA
ROOM: Building N7-2 #3304
TELEPHONE : 3714
Cellphone : 010 –
TA : Donggi Lee
ROOM: Building N7-2 # 1304
TELEPHONE : 5754
Cellphone : 010 –

2. SYLLABUS (1/4) COURSE CODE : AE 410
COURSE NAME : COMBUSTION ENGINEERING
PROFESSOR : SEUNG WOOK BAEK (Rm #3304, Ext. 3714)
GRADING SYSTEM
1 Final Exam ( June 8th, 2017 )
Homeworks

3. CURRENT ISSUES IN COMBUSTION SCIENCE & TECHNOLOGY
How to efficiently mix fuel and oxidizer
Convection and diffusion
How to efficiently burn fuel and oxidizer: energy saving
How to reduce pollutant emission such as CO,CO2 and NOx
How to improve safety and reduce impact on environment
To develop green, sustainable and alternative energy

4. SYLLABUS (2/4) REFERENCES
F.A.Williams, “Combustion Theory,” Addison Wesley, 2nd Ed.
D.B.Spalding, “Combustion and Mass Transfer,” Pergamon Press
I.Glassman, “Combustion,” Academic Press, 2nd Ed.
M.Kanury, “Introduction to Combustion Phenomena,” Gordon and Breach Science Publishers
P.A.Libby and F.A.Williams (Editors), “Turbulent Reacting Flows,” Springer Verlag
L.A.Kennedy (Editor), “Turbulent Combustion,” Progress in Astronautics and Aeronautics, Vol.58

5. SYLLABUS (3/4) JOURNALS K.K.Kuo, “Principles of Combustion,” Wiley
V.R.Kuznetsoz and V.A.Sabelnikov, “Turbulence and Combustion,” Hemisphere Publishing Corporation
JOURNALS
Combustion and Flame
Combustion Science and Technology
Symposium (International) on Combustion
Combustion Theory and Modeling
AIAA Journal
Progress in Energy and Combustion Science

6. SYLLABUS (4/4) Combustion, Explosion and Shock Waves
Progress in Astronautics and Aeronautics
Fire Safety Journal
International Journal of Heat and Mass Transfer
Journal of Heat Transfer
Journal of Thermophysics and Heat Transfer
Journal of Propulsion and Power

7. Combustion Engineering
Thermochemistry
Combustion- high temperature, moderate or high pressure, perfect gas, real gas effects for high pressure environment
Thermodynamic properties of a single perfect gas
Equation of state :
: Universal gas constant
: Molecular weight
: Concentration
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

8. Combustion Engineering
Internal Energy
: per unit mass
: Internal energy of formation
: Specific heat
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

9. Combustion Engineering
Enthalpy or =
: Enthalpy of formation
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

10. Combustion Engineering
Only change in or is important (not the absolute level)
Need a convention for and
1) Prescribe a standard state, i.e.,
and
2) The formation enthalpy of the chemical elements in their
natural phase at and will be zero.
3) ,
for, : : : : :
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

11. Combustion Engineering
Entropy
Let = Entropy at and any temperature .
Gibbs Free Energy
per unit mass basis
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

12. Combustion Engineering
On a molar basis
: Molar basis
Helmholtz Free Energy
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

13. Combustion Engineering
Mixture of perfect gases ;
: Total number of moles per unit volume
: Total number of moles of species K per unit volume
: Mole fraction of species K
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

14. Combustion Engineering
: Density of the mixture
: Partial density of species K
: Mass fraction of species K
: Molecular weight of species K ,
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

15. Combustion Engineering
: Mean molecular weight of the mixture
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

16. Partial pressure exerted by species K if it occupies
EQUATION OF STATE
Partial pressure exerted by species K if it occupies
the whole volume at temperature T.
PROPULSION AND COMBUSTION LABORATORY

17. Dalton’s Law
but
Internal Energy
PROPULSION AND COMBUSTION LABORATORY

18. where
PROPULSION AND COMBUSTION LABORATORY

19. Enthalpy
when is fixed
Entropy
PROPULSION AND COMBUSTION LABORATORY

20. PROPULSION AND COMBUSTION LABORATORY

21. PROPULSION AND COMBUSTION LABORATORY

22. Caution ;
When there is reaction
PROPULSION AND COMBUSTION LABORATORY

23. Specification of Composition
Problem for notes
Binary mixture of
Specification of Composition
For same
PROPULSION AND COMBUSTION LABORATORY

24. For same P and T, partial volume of species K
Here, is not so that
PROPULSION AND COMBUSTION LABORATORY

25. Material Balance for Chemical Reactions
Ex) Combustion of Octane with Air
Air:
Molecular Weight:
For complete combustion (stoichiometric)
Stoichiometric Coefficients:
PROPULSION AND COMBUSTION LABORATORY

26. or 15.1 kg of air/ 1 kg of octane For reactants
On a mass basis,
or 15.1 kg of air/ 1 kg of octane
For reactants
PROPULSION AND COMBUSTION LABORATORY

27. MASS OF PRODUCTS = 1831 : MEAN MOLECULAR WEIGHT OF REACTANTS
PROPULSION AND COMBUSTION LABORATORY

28. EQUIVALENCE RATIO :
FOR
PROPULSION AND COMBUSTION LABORATORY

29. ENERGY Eq. FOR CHEMICAL REACTION CONSTANT VOLUME SYSTEM – NO MOTION
: STOICHIOMETRIC
: FUEL LEAN
: FUEL RICH
FOR
FOR
ENERGY Eq. FOR CHEMICAL REACTION
CONSTANT VOLUME SYSTEM – NO MOTION
PROPULSION AND COMBUSTION LABORATORY

30. (POSITIVE WHEN ADDED TO THE SYSTEM) : INTERNAL ENERGY
1st LAW :
: HEAT TRANSFER
(POSITIVE WHEN ADDED TO THE SYSTEM)
: INTERNAL ENERGY
: WORK DONE BY THE SYSTEM
1: REACTANT STATE
2: PRODUCT STATE
PROPULSION AND COMBUSTION LABORATORY

31. ONLY IMPORTANCE IS , NOT THE ABSOLUTE VALUES.
: REFERENCE OR
BASIC TEMPERATURE
: INTERNAL ENERGY OF REACTION,
DETERMINED IN A BOMB CALORIMETER
PROPULSION AND COMBUSTION LABORATORY

32. FOR CONSTANT PRESSURE PROCESS;
PROPULSION AND COMBUSTION LABORATORY

33. FOR PERFECT GASES; : ENTHALPY OF REACTION
:INTERNAL ENERGY OF REACTION AT
FOR PERFECT GASES;
PROPULSION AND COMBUSTION LABORATORY

34. ENTHALPY OF FORMATION AND ENTHALPY OF COMBUSTION
ENTHALPY OF FORMATION -THAT CHANGE OF ENTHALPY WHICH OCCURS WHEN A COMPOUND IS FORMED FROM THE ELEMENTS, WHICH ARE IN THEIR STABLE STATE, AT SAME STANDARD TEMPERATURE AND PRESSURE.
PROPULSION AND COMBUSTION LABORATORY

35. GIVES OFF 94052 cal :exothermic reaction
HEAT OF FORMATION =
ALSO A COMBUSTION PROCESS
ENTHALPY OF COMBUSTION
HEAT OF COMBUSTION
HEAT OF COMBUSTION OF
PROPULSION AND COMBUSTION LABORATORY

36. HEATING VALUES; FOR C+O2 REACTION,
ENDOTHERMIC REACTION
HEATING VALUES; FOR C+O2 REACTION,
, BECAUSE THERE IS NO WORKS.
IN GENERAL,
HIGHER HEATING VALUES AND LOWER HEATING VALUES DEPEND ON STATE OF PRODUCTS.
PROPULSION AND COMBUSTION LABORATORY

37. IMPORTANT CASE IS vs. IF IS LIQUID,
LHV DIFFERS FROM HHV BY HEAT OF VAPORIZATION.
PROPULSION AND COMBUSTION LABORATORY

38. REFERENCES FOR THERMOCHEMICAL DATA
NBS, “Tables of Selected Values of Chemical Thermal Properties”, Circular Letter 500
JANAF Thermo-Chemical Tables (1993)
Penner’s Book
Van Wylen & Sonntag (SI units)
CHEMKIN: Software package for the analysis of gas-phase chemical and plasma kinetics (2000)
EXAMPLE
10g OF H2 (g) BURN IN AIR (=1) AT CONSTANT PRESSURE. INITIAL TEMPERATURE IS 298K AND FINAL TEMPERATURE IS 2000K SO THAT H2O IS GASEOUS. CALCULATE THE HEAT LIBERATED ;
PROPULSION AND COMBUSTION LABORATORY

39. PROPULSION AND COMBUSTION LABORATORY

40. IF THE PROBLEM WERE AT CONSTANT VOLUME,
MINUS INDICATES THAT HEAT WAS TRANSFERRED OUT OF THE SYSTEM. IN OTHER WORDS, THE FLAME TEMPERATURE, IF ADIABATIC, WOULD BE HIGHER THAN 2000 K.
IF THE PROBLEM WERE AT CONSTANT VOLUME,
PROPULSION AND COMBUSTION LABORATORY

41. CALCULATION OF ENTHALPY OF REACTION FROM THE ENTHALPY OF FORMATION
PROPULSION AND COMBUSTION LABORATORY

42. EX) GASEOUS CH4 + O2 REACT TO YIELD H2O(l)+CO2(g).
CALCULATE PER MOLE OF CH4
EXOTHERMIC PER MOLE OF CH4
PROPULSION AND COMBUSTION LABORATORY

43. CONSIDER A CHEMICAL SYSTEM OF CONSTANT MASS EITHER HOMOGENEOUS OR HETEROGENEOUS IN MECHANICAL AND THERMAL EQUILIBRIUM BUT NOT IN CHEMICAL EQUILIBRIUM. THE SYSTEM IS IN CONTACT WITH A RESERVOIR AT TEMPERATURE T AND UNDERGOES AN INFINITESIMAL IRREVERSIBLE EXCHANGE OF HEAT, Q, TO THE RESERVOIR. PROCESS MAY INVOLVE CHEMICAL REACTION AND TRANSPORT BETWEEN PHASES.
PROPULSION AND COMBUSTION LABORATORY

44. FROM SYSTEM dS: ENTROPY CHANGE OF THE SYSTEM
dSO: ENTROPY CHANGE OF THE RESERVOIR
dS+dSo: ENTROPY CHANGE OF THE UNIVERSE
FROM SYSTEM
PROPULSION AND COMBUSTION LABORATORY

45. CASE A ; HOLD E AND V CONSTANT
1ST LAW
FROM SYSTEM
VARIOUS CONSTRAINTS
CASE A ; HOLD E AND V CONSTANT
ISOLATED SYSTEM
CASE B ; HOLD p AND T CONSTANT
GIBBS FREE ENERGY DECREASES
PROPULSION AND COMBUSTION LABORATORY

46. WHEN ; HAVE CHEMICAL EQUILIBRIUM-
WHEN ; HAVE CHEMICAL EQUILIBRIUM
CASE C ; HOLD V AND T CONSTANT
AT EQUILIBRIUM ;
PROPULSION AND COMBUSTION LABORATORY

47. EQUILBRIUM OF A MIXTURE OF PERFECT GASES UNDERGOING CHEMICAL REACTION
CONSIDER THE REACTION,
WE KNOW GIBBS FREE ENERGY FOR AND ANY TEMPERATURE T PER MOLE.
AT ANY T AND P ;
, ETC
PROPULSION AND COMBUSTION LABORATORY

48. LET
PROPULSION AND COMBUSTION LABORATORY

49. DEFINE
AT EQUILIBRIUM
NOTE THAT
PROPULSION AND COMBUSTION LABORATORY

50. EFFECT OF T ON EQUILIBRIUM COMPOSITION IS GIVEN IN Kp
WHERE
EFFECT OF T ON EQUILIBRIUM COMPOSITION IS GIVEN IN Kp
EFFECTS OF p ON THE TERM.
FOR THE CASE OF , IE. C + D = A + B
NO PRESSURE EFFECT
EQUILIBRIUM CONSTANT BASED ON CONCENTRATION ;
PROPULSION AND COMBUSTION LABORATORY

51. VALUES OF KP ARE TABULATED FOR SPECIFIC CHEMICAL REACTION.
, ETC
VALUES OF KP ARE TABULATED FOR SPECIFIC CHEMICAL REACTION.
EX) DISSOCIATION OF CO2
(1)
PROPULSION AND COMBUSTION LABORATORY

52. EQUILIBRIUM COMPOSITION
(2)
(3)
EQUILIBRIUM COMPOSITION
EX) 100% WATER VAPOR, INITIALLY AT 1 atm AND 2200 K DISSOCIATES INTO H2 (g) AND O2 (g). ASSUMING PERFECT GASES THROUGHOUT, DETERMINE THE EQUILIBRIUM COMPOSITION
PROPULSION AND COMBUSTION LABORATORY

53. EQUILIBRIUM COMPOSITION
CHEMICAL REACTION
EQUILIBRIUM COMPOSITION
PROPULSION AND COMBUSTION LABORATORY

54. EQUILIBRIUM
COMPOSITION
PROPULSION AND COMBUSTION LABORATORY

55. EXAMINE LIMITING CONDITIONS
CASE I - LOW TEMPERATURES
; VERY LITTLE DISSOCIATION
LET OR
HIGHER PRESSURE ; LOWER  ; GREATER
LESS DISSOCIATION
B) HIGHER TEMPERATURE ; HIGHER KP GREATER  ; SMALLER
MORE DISSOCIATION
PROPULSION AND COMBUSTION LABORATORY

56. CASE II - HIGH TEMPERATURES ; HIGH DISSOCIATIONOR
HIGHER PRESSURE ; HIGHER  ; HIGHER
LESS DISSOCIATION
HIGHER TEMPERATURE ; HIGHER KP ; LOWER  =
MORE DISSOCIATION
PROPULSION AND COMBUSTION LABORATORY

57. EQUILIBRIUM WHEN SIMULTANEOUS REACTIONS OCCURRING
THE NUMBER OF INDEPENDENT REACTIONS, WHICH MUST BE CONSIDERED IN EQUILIBRIUM CALCULATIONS, IS EQUAL TO THE LEAST NUMBER OF EQUATIONS WHICH INCLUDE ANY REACTANT AND PRODUCT WHICH ARE PRESENT TO AN APPRECIABLE DEGREE IN THE EQUILIBRIUM MIXTURE.
EX) CALCULATE THE COMPOSITION OF THE EQUILIBRIUM MIXTURE OBTAINED WHEN 5 MOLES OF STEAM, H2O (g) REACT WITH 1 MOLE OF CH4 AT ELEVATED TEMPERATURE AND SOME ARBITRARY PRESSURE
PROPULSION AND COMBUSTION LABORATORY

58. MECHANISM FOR REACTION ; 2 ACTUAL REACTIONS ARE ;
C : 1 = a + c + e
H : 14 = 4a + 2b + 2d
O : 5 = b + c + 2e
MECHANISM FOR REACTION ;
2 ACTUAL REACTIONS ARE ;
PROPULSION AND COMBUSTION LABORATORY

59. (1)
(2)
PROPULSION AND COMBUSTION LABORATORY

60. PRODUCT RULE FOR KP’s (1) (2) (3) ADD
PROPULSION AND COMBUSTION LABORATORY

61. ADIABATIC FLAME TEMPERATURE
POINT (2) FINAL TEMPERATURE AND H AFTER
A NON-ADIABATIC REACTION
POINT (2i) ISOTHERMAL REACTION
POINT (c) ADIABATIC FLAME TEMPERATURE ; H2=H1
PROPULSION AND COMBUSTION LABORATORY

62. CONSTANT PRESSURE REACTION – GENERAL CASE
DETERMINE TC FROM H2=H1
H2 DEPENDS ON THE bi WHICH DEPENDS ON Tc WHICH DEPENDS ON THE bi.
PROPULSION AND COMBUSTION LABORATORY

63. FOR PERFECT GASES TO CALCULATE Tc WHERE ASSUME TC FOR GIVEN PRESSURE
CALCULATE THE bi FROM THE KP’s
SUBSTITUTE INTO H2=H1
ITERATE UNTIL H2=H1
PROPULSION AND COMBUSTION LABORATORY

64. CALCULATE THE ADIABATIC FLAME TEMPERATURE OF A  = 0
CALCULATE THE ADIABATIC FLAME TEMPERATURE OF A  = 0.8 METHANE – O2 MIXTURE AT p = 10 atm, TAKING INTO ACCOUNT THE DISSOCIATION OF CO2 AND H2O
2 UNKNOWNS
PROPULSION AND COMBUSTION LABORATORY

65. Combustion Engineering
etc.
Dissociation Reactions
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

66. Combustion Engineering
Procedure ; assume Tc; Calculate a,b,c,d,e
Substitute into H2=H1 (from Energy Equation)
If Tc=3000K
Hco2
HH20
a[ kcal/mole ]+b[ ]
+c[ ]+d[ ]
+e[ ] = 0.8[-17.89]+2[0]
Hco
HH2
Ho2
HCH4
Ho2
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

67. Combustion Engineering
Tables of Thermodynamic Properties
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

68. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

69. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

70. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

71. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

72. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

73. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

74. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

75. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

76. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

77. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

78. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

79. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering

80. Combustion Engineering
PROPULSION AND COMBUSTION LABORATORY
Combustion Engineering