RADIATION AND COMBUSTION PHENOMENA 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 : Jonghan Won ROOM: Building N7-2 # 3315 TELEPHONE : 3754 Cellphone : 010 - 4705 - 4349 won1402@kaist.ac.kr

RADIATIVE HEAT TRANSFER GAS RADIATION EXAMPLE THIS PROBLEM HAS SOME OF THE FEATURES OF A FLAME IN A PREMIXED COMBUSTABLE GAS STREAM. ew PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION FOR THIN GAS LINEARIZE PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION INTRODUCE INTRODUCE PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION FOR , SHOULD APPROACH RATHER THAN ! WHAT IS WRONG? PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION EXAMPLE RADIATION AFFECTED STEADY BUOYANCY DRIVEN FLOW IN A VERTICAL SLOT BASIC ASSUMPTION INCOMPRESSIBLE FLOW EXCEPT FOR BUOYANCY (BOUSSINESQ APPROXIMATION: FOR VERY SMALL DENSITY CHANGE) PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION MASS (PARALLEL FLOW IN x) X- MOMENTUM IF THE TEMPERATURE WERE TO APPROACH A UNIFORM VALUE, SAY , THEN CONVECTION WOULD STOP. PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION IS THE HYDROSTATIC PRESSURE CORRESPONDING TO DENSITY AND TEMPERATURE . ENERGY (THERMAL) MOTION HAS NO EFFECT ON TEMPERATURE DISTRIBUTION ! (SOLVED BEFORE) FOR BUOYANCY DRIVEN FLOW, THEN LET PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION FOR COMBINED (FORCED BUOYANCY DRIVEN) FLOWS, THE PRESSURE TERM BECOMES APPRECIABLE. CONSTITUTION MOTION IS GOVERNED BY FOR MOST OF NATURAL CONVECTION PROBLEM, THE DENSITY VARIATION IS MAINLY CAUSED BY THE THERAMAL EXPANSION OF THE FLUID. PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION INTRODUCE , COEFFICIENT OF THERMAL EXPANSION THEN AND FROM THE PREVIOUS RESULTS ON LINEARIZED THIN GAS BETWEEN TWO PLATES PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER SLIDE 22 IN FILE 7 GAS RADIATION REARRANGE PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION INTEGRATE TWICE PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION BC’S FROM FROM WITH PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION OR IN TERMS OF OR PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION FINALLY, THE CONDITION OF NO NET FLOW, GIVES THE TEMPERATURE WHICH IS THE BASE FOR BUOYANCY. PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

RADIATIVE HEAT TRANSFER GAS RADIATION WHICH GIVES WHAT HAPPENS AS OR ? HW#5 [REF.1] P.734 #14-1, 14-4 PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

HW#5 [REF.1] P.734 #14-1, 14-4 14-1. A slab of non-scattering solid material has a gray absorption coefficient of and refractive index . It is 2 cm thick and has an approximately linear temperature distri- bution within it as established by thermal conduction. What is the emitted intensity normal to the slab? What average slab temperature would give the same emitted normal intensity? 14-4. A non-scattering stagnant gray medium with absorption coefficient is contained between black parallel plates 10 cm apart as shown (assume constant density and ). Plot the temperature distribution T(z) (neglect thermal conduction). What is the net energy flux being transferred by radiation from the lower to the upper plate? If the plates are gray with ε1 = 0.8 and ε2 = 0.4, what is the energy flux being transferred? < 14-1 > < 14-4 >