290 likes | 444 Views
C OMBUSTION E NGINEERING. P ROF . S EUNG W OOK B AEK D IV . OF A EROSPACE E NGINEERING , KAIST, IN KOREA R OOM : 3304 T ELEPHONE : 3714. P HYSICAL P ICTURE OF C OMBUSTION WAVE. V ERY S MALL I GNITION E NERGY – E XTINGUISHED
E N D
COMBUSTION ENGINEERING PROF. SEUNG WOOK BAEK DIV.OFAEROSPACE ENGINEERING, KAIST, IN KOREA ROOM : 3304 TELEPHONE : 3714
PHYSICAL PICTURE OF COMBUSTION WAVE VERY SMALL IGNITION ENERGY – EXTINGUISHED Vs = SPACE VELOCITY OF THE FLAME ; I.E. RELATIVE TO WALL Vu = VELOCITY OF UNBURNED MIXTURE RELATIVE TO WALL Vf= VELOCITY OF THE FLAME RELATIVE TO THE UNBURNED MIXTURE Vf = Vs –Vu :BURNING VELOCITY PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
INSTANTANEOUS GENERATION OF A C-JDETONATION VCJ U = 0 Vc P(x) Vc STAGNANT BURNED GAS V(x) P1 PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
STRUCTURE OF THE DETONATION WAVE INDUCTION ZONE 2S UNBURNED COMBUSTION V2 VCJ CJ (2) IGNITION DELAY TIME P1 T2 P2S VCJ T2S PCJ T1 V2 P1 V2S PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
USUALLY GET Chapman-JouguetDETONATION ; PROPERTIES OF C-JDETONATION MASS-MOMENTUM-ENERGY FOR C-JWAVES AND PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
VALID FOR C-JDETONATION OR DEFLAGRATION PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
FOR DETONATION, OR OR OR PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
C-J DETONATION VELOCITY DEPENDS ONLY ON THE HEAT RELEASE Q, INDEPENDENT OF . THEREFORE, VARIES WITH ONLY BECAUSE THE SPEED OF SOUND CHANGES. PRESSURE RATIO, OR PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
FROM MASS, MOMENTUM, AND ENERGY OR OR PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
MACH NUMBER OF BURNED GASES RELATIVE TO THE WALLS FOR C-J (HIGH SUBSONIC) PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
COMPARISON BETWEEN PRESSURE BEHIND A SHOCK & C-JDETONATION FOR THE SAME MACH NUMBER Q 2S (1) PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
FOR C-JDEFLAGRATION, (GOOD FOR C-JDETONATION & DEFLAGRATION) FOR C-JDEFLGRATION, PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
GET (FOR C-JDETONATION) FOR DEFLAGRATION M= 1/6 EXAMPLE FOR THE C-JDETONATION OF MIXTURE PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
DIFFERNTIAL EQUATION OF TRANSPORT OF MATTER AND ENERGY INCLUDING COMBUSTION REAL COMBUSTION PHENOMENA INVOLVE HUNDREDS OF INTERACTING CHEMICAL REACTIONS. BUT FOCUS ATTENTION ON A MODEL OF COMBUSTION, WHICH ACCORDS WITH REALITY IN RESPECT OF THE OVERALL EFFECTS. PURPOSE : QUANTITATIVE PREDICTIONS OF COMBUSTION PHENOMENA PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
SIMPLE CHEMICALLY REACTING SYSTEM (SCRS) FUEL + OXIDANT PRODUCT 1 S 1+S S : STOICHIOMETRIC RATIO REACTANTS PRODUCE A UNIQUE PRODUCT IN FIXED PROPORTIONS BY MASS. INDEPENDENT OF TEMPERATURE PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
H : HEAT OF COMBUSTION IF AND PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
FOR STEADY 1-DDIFFUSION-CONTROLLED FLAMES THE FUEL AND OXIDIZER COMBINE WITH A FIXED STOICHIOMETRIC RATIO S : AND IF PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
OBEYS THE SAME DIFFERENTIAL EQUATION AS THE MASS FRACTION OF A CHEMICALLY INERT MATERIAL DOES. PRECISE KNOWLEDGE OF THE ‘S IS NOT NECESSARY. FOR SCRS • NO VISCOUS SHEAR WORK • NO KINETIC ENERGY EFFECTS • NO EXTERNAL ENERGY SOURCES PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
THE TWO STREAM MIXING PROCESS (AN IDEALIZATION OF COMBUSTION CHAMBER FLOWS) FOR ANY EXTENSIVE PROPERTY OF A FLUID WHICH IS FREE FROM SOURCES AND SINKS : CONSERVED PROPERTY : MIXTURE FRACTION PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
EX) min : MASS FRACTION OF AN INERT COMPONENT , , AND ANY LINEAR COMBINATION OF SUCH CONSERVED PROPERTIES: IF THE MIXING PROCESS IS ADIABATIC AND FREE FROM WORK INPUT, STAGNATION ENTHALPY IS A CONSERVED PROPERTY PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
THE FUEL AND OXIDANT MASS FRACTION ARE LINKED WITH IF F : FUEL, A : OXYGEN WITH DILUENT PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
AFTER CHEMICAL REACTION IS COMPLETED. PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING
IT SHOULD BE OBSERVED THAT THE MIXTURE FRACTION WILL OBEY THE SAME DIFFERENTIAL EQUATIONS AS DO AND . PROPULSION AND COMBUSTION LABORATORY COMBUSTION ENGINEERING