COMBUSTION TA : Donggi Lee PROF. SEUNG WOOK BAEK DEPARTMENT OF AEROSPACE ENGINEERING, KAIST, IN KOREA ROOM: Building N7-2 #3304 TELEPHONE : 3714 Cellphone : 010 - 5302 - 5934 swbaek@kaist.ac.kr http://procom.kaist.ac.kr TA : Donggi Lee ROOM: Building N7-2 #1304 TELEPHONE : 5754 Cellphone : 010 - 8504 - 5841 kingdonggi@kaist.ac.kr

COMBUSTION ENGINEERING THE Shvah-Zeldovitch FORMULATION OF EQUATIONS OF MULTI-COMPONENT REACTING GASES ASSUMPTION NEGLECT (A) BODY FORCE (B) THERMAL DIFFUSION (SORET EFFECT) (C) PRESSURE GRADIENT DIFFUSION (D) BULK VISCOSITY (E) RADIATION STEADY FLOW OVERALL CONTINUITY IN MOST OF LOW SPEED COMBUSTION PROBLEMS VISCOUS TERMS ARE NEGLECTED, IF PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING   MOMENTUM EQUATION : JUSTIFICATION ONE DIMENSIONAL SPECIES EQUATION CHEMICAL TIME PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING IF v0 IS A CHARACTERISTIC VELOCITY, : CHARACTERISTIC CHEMICAL LENGTH ~ ORDER OF DISTANCE IN WHICH REACTION IS COMPLETED ~ REACTION ZONE THICKNESS (MANY MOLECULAR COLLISIONS ARE NEEDED) INTEGRATE 1D MOMENTUM EQUATION ONCE PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING IN REGION WHERE VISCOUS EFFECTS ARE IMPORTANT : VISCOUS TIME VISCOUS LENGTH : LENGTH IN WHICH TRANSLATIONAL AND RATATIONAL MODES ARE EQUILIBRIATED: ONE OR TWO COLLISIONS ~ MEAN FREE PATH PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING : IN ATMOSPHERE DIMENSIONLESS VARIABLES PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING WHY BECAUSE CONTINUITY MOMENTUM PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING If : MASS PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING STEADY STATE ENERGY EQUATION NEGLECT KINETIC ENERGY VISCOUS WORK BODY FORCE RADIATION (1) = SPECIFIC INTERNAL ENERGY = HEAT FLUX = (2) PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING SUBSTITUTE INTO PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING ENERGY EQUATION BECOMES (3) (4) SPECIES CONSERVATION, (5) PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING PUT (5) IN (4), (6) PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING (6) SECOND TERM IN (6), USE (7) (8) USE (9) PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING COMBINE (8) & (9) THEN (6) BECOMES, (10) PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING ASSUME THEN (11) RETURN TO SPECIES, COMBINE EQUATIONS (5) & (7) (12) REMARKS : Shvah-Zeldovitch FORM OF EQUATIONS. Cp’s & Cpi’s ARE NOT NECESSARILY CONSTANT. PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING SINGLE REACTION STEP LAW OF MASS ACTION THE RATE OF PRODUCTION OF A CHEMICAL SPECIES IS PROPORTIONAL TO THE PRODUCTS OF THE CONCENTRATION OF EACH REACTANT WITH EACH CONCENTRATION RAISED TO A POWER EQUAL TO ITS STOICHIOMETRIC COEFFICIENT. = CONCENTRATION OF SPECIES i = MOLES PER UNIT VOLUME PER SECOND FORMED OF SPECIES i PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING ALSO WE CAN WRITE, k = SPECIFIC REACTION RATE CONSTANT PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING = RATE OF PRODUCTION FOR ANY SPECIES (MOLES/UNIT VOLUME/S) = MOLECULAR WEIGHT OF SPECIES i PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING FOR SPECIES AND ENERGY EQUATIONS WITH SINGLE REACTION, EACH CAN BE REDUCED TO THE FORM FOR ENERGY EQUATION FOR SPECIES EQUATION PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING L : A LINEAR OPERATOR : NON LINEAR: INVOLVES PRODUCTS OF ‘S OFTEN : ARRHENIUS TYPE SINCE REMARKS ) MAY BE IMPLICITLY NON-LINEAR BECAUSE OF DEPENDENCE OF ON PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING DIFFUSION FLAME ANY FLAME IN WHICH FUEL AND OXIDIZER ARE ORIGINALLY UNMIXED EXAMPLES) CANDLE FLAME PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING DROPLET BURNING INDIVIDUAL DROPLET BURNING OXIDIZER PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING BOUNDARY LAYER ADJACENT TO FUEL SURFACE OXIDIZER FUEL OXIDIZER PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING JET FLAME PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING LAMINAR DIFFUSION FLAMES ARE CHARACTERIZED BY REACTION RATES FAST COMPARED TO RATES OF MASS AND ENERGY TRANSFERS BY DIFFUSION AND CONVECTION REACTION TENDS TO BE CONCENTRATED IN THIN FRONTS WHERE FUEL AND OXIDIZER ARE IN STOICHIOMETRIC PROPORTION. RATE OF CONVERSION OF MIXTURE IS SLOWER THAN THAT IN PREMIXED FLAME PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING (4) WHEN JET VELOCITY EXCEEDS A CERTAIN VALUE THE FLAME BECOMES TURBULENT FLAME HEIGHT JET VELOCITY Hottel and Hawtherns 3RD SYMPOSIUM ON COMBUSTION (1949) LARMINAR TRANSITION TURBULENT PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING QUALITATIVE ANALYSIS L r d V0 OXIDIZER RELATION BETWEEN FLAME HEIGHT L TUBE DIAMETER d FUEL VELOCITY V0 (OR FLOW RATE ) MASS FLOW ~ RATE AT WHICH FUEL AND OXIDIZER MIX BY DIFFUSION PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING FOR GIVEN FUEL D INDEPENDENT OF FOR TURBULENT FLOW REPLACE D BY A TURBULENT DIFFUSION COEFFICIENT, PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING

COMBUSTION ENGINEERING Dt (TURBULENT SCALE)(TURBULENT INTENSITY) SIZE OF LARGEST EDDY L INDEPENDENT OF JET VELOCITY PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING