1. R ADIATION AND C OMBUSTION P HENOMENA P ROF. S EUNG W OOK B AEK D EPARTMENT OF A EROSPACE E NGINEERING, KAIST, IN KOREA R OOM : Building N7-2 #3304 T ELEPHONE : 3714 Cellphone: 010 – 5302 - 5934 swbaek@kaist.ac.kr http://procom.kaist.ac.kr T A : Bonchan Gu R OOM : Building N7-2 # 3315 T ELEPHONE : 3754 Cellphone: 010 – 3823 - 7775 ryan.bonchan@kaist.ac.kr P ROF. S EUNG W OOK B AEK D EPARTMENT OF A EROSPACE E NGINEERING, KAIST, IN KOREA R OOM : Building N7-2 #3304 T ELEPHONE : 3714 Cellphone: 010 – 5302 - 5934 swbaek@kaist.ac.kr http://procom.kaist.ac.kr T A : Bonchan Gu R OOM : Building N7-2 # 3315 T ELEPHONE : 3754 Cellphone: 010 – 3823 - 7775 ryan.bonchan@kaist.ac.kr

2. G RADING S YSTEM Homework (20%), 1 Final Exam (80%) T EXT : None R EFERENCES … 1.Siegel, R. and Howell, J.R., Thermal radiation heat transfer, 4 th, Taylor&Francis, 2002 2.Sparrow, E.M. and Cess, R.D., Radiation heat transfer, Brooks/Cole Publishing Company, 1970 3.Michael F. Modest, Radiative Heat transfer, 2 nd Academic Press, 2003 4.M. Quinn Brewster, Thermal Radiative Heat Transfer and Properties, Wiley-Interscience, 1992 R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY

3. O UTLINE… PART I. RADIATIVE EQUILIBRIUM PART II. RADIATIVE NON-EQUILIBRIUM 1.ENCLOSURE (SURFACE) RADIATION 2.GAS RADIATION PART III. RADIATIVE PROPERTIES PART IV. RADIATION AFFECTED TRANSPORT PHENOMENA R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY

4. T HERMAL R ADIATION A fundamental difference between conduction and radiation is in their distribution. R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY I NTRODUCTION ConductionRadiation Temporal Spatial Specular Distribution Geometry Quantum mechanics Optics Explicitly,

5. Its importance becomes intensified at high temperature levels: furnaces, combustion chamber, rocket nozzle, nuclear power plant, etc. No medium required With conduction and convection – nonlinear integro- differential equation : Difficult to solve!!! Radiative physical property depends on surface roughness, material, thickness of coating, temperature, angle, etc. R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY I NTRODUCTION

6. Classical electromagnetic wave theory T HEORY OF R ADIANT E NERGY P ROPAGATION E XCEPTIONS Spectral distribution of the energy emitted from a body and the radiative properties of gases - explained by only quantum mechanics [particle(photon) theory] R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY I NTRODUCTION

7. S PECTRUM OF E LECTROMAGNETIC R ADIATION R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY I NTRODUCTION

8. S PECTRUM OF E LECTROMAGNETIC R ADIATION NEAR V ISIBLE R AY R EGION R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY I NTRODUCTION Wavelength [ ㎛ ] 0.1 1 0.0110100 0.001 1000 Ultraviolet Red Infra-red Violet Thermal Visible 0.40.7

9. P ART I. R ADIATIVE E QUILIBRIUM A D IRECTIONAL V OLUME S OLID A NGLE R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY

10. T WO M ORE D EFINITIONS D IFFERENTIATE WITH R ESPECT TO F ROM THIS R ELATION R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

11. F OR I SOTROPIC R ADIATION AT E QUILIBRIUM D IVIDE BY, D IFFERENTIATE WITH R ESPECT TO THERMALOPTICS emissive power unprojected area projected area R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

12. F OR I SOTROPIC B LACKBODY R ADIATION AT E QUILIBRIUM R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

13. T HEN, THERMALOPTICS Stefan-Boltzmann Law : Stefan-Boltzmann Constant R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

14. D EFINITION … An ideal body that allows all the incident radiation to pass into it ( no reflected energy) and absorbs internally all the incident radiation ( no transmitted energy) ; perfect absorber of incident radiation. P ERFECT E MITTER IN E ACH D IRECTION AND AT E VERY W AVE L ENGTH In equilibrium condition, the blackbody must radiate exactly as much energy as it absorbs. The intensity of radiation from a blackbody is independent of the direction of emission. B LACKBODY R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

15. S PECTRAL D ISTRIBUTION OF B LACKBODY E MISSIVE P OWER R ADIATIVE E QUILIBRIUM UNIFORM ISOTROPIC M ATTER R ADIATION FOR S PHERE R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM U SING S IMILARLY

16. : Wien’s (D ISPLACEMENT ) L AW R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM At a higher temperature, the peak intensity shifts to a shorter wavelength

17. F ROM Wien’s L AW M ONOCHROMATIC ( S PECTRAL ) B LACKBODY E MMISIVE P OWER AT E QUILIBRIUM WITH, R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

18. H AS A M AXIMUM AT W AVELENGTH FOR A G IVEN T EMPERATURE R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

19. H EMISPHERICAL S PECTRAL E MISSIVE P OWER OF B LACKBODY FOR S EVERAL D IFFERENT T EMPERATURES R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

20. When radiation travels from one medium into another, the frequency remains constant while the wavelength changes because of the change in propagation velocity. Wave number : the number of waves per unit length. R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

21. BLACKBODY EMISSION INTO VACUUM T HE Planck D ISTRIBUTION OF THE M ONOCHROMATIC E MISSIVE P OWER WHERE F ROM O RIGIN OF Q UANTUM M ECHANICS R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM Planck’s constant : Boltzmann’s constant :

22. T HE Rayleigh-Jeans D ISTRIBUTION F OR R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

23. S PECTRAL D ISTRIBUTION OF B LACKBODY H EMISPHERICAL E MISSIVE P OWER R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

24. 1.Energy emitted at all wave lengths increases as the temperature increases. 2. Peak spectral emissive power shifts toward a smaller wavelength as the temperature is increased. 3.Red light becomes visible first as the temperature is raised – at sufficiently high temperature, the light emitted becomes white. C HARACTERISTICS… R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

25. T EMPERATURE M EASUREMENT U SING 4 W AVELENGTH P YROMETER Planck’s D ISTRIBUTION L AW F OR N ON-BLACKBODIES, R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

26. T HE I NTENSITY OF R ADIATION M EASURED BY A P HOTODIODE FOR GRAY BODIES a calibration factor including all radiation absorbed between the emission source and the photodiode (e.g. windows, optical elements, filter, etc.) R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

27. F OR N ON- G RAY B ODY S HOULD D ETERMINEFOR C ALIBRATION U SING G RAPHS FOR R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

28. E MISSIVITY OF T UNGSTEN R IBBON AS A F UNCTION OF T EMPERATURE FOR D IFFERENT W AVELENGTH R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

29. R ELATIVE E MISSIVE P OWER AS A F UNCTION OF W AVELENGTH FOR D IFFERENT T EMPERATURES R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM

30. R ELATIVE V OLTAGE O UTPUTS U SING T UNGSTEN L AMP AS A FUNCTION OF T EMPERATURE D EPENDING ON D IFFERENT C HANNELS AND D IFFERENT S ETUPS R ADIATIVE H EAT T RANSFER P ROPULSION AND C OMBUSTION L ABORATORY R ADIATIVE E QUILIBRIUM