AEROSPACE ENGINEERING LABORATORY (MAE308)

1 AEROSPACE ENGINEERING LABORATORY (MAE308)PROF. SEUNG WO...
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1 AEROSPACE ENGINEERING LABORATORY (MAE308)PROF. SEUNG WOOK BAEK Department of AEROSPACE ENGINEERING, KAIST, IN KOREA ROOM: Building N7-2 #3304 TELEPHONE: 3714 MOBILE: TA : Jonghan Won ROOM: Building N7-2 #3315 TELEPHONE : 3754 MOBILE:

2 Observation of Radiation Emitted from Light Source Using SpectrometerContents Background Experimental setup Objectives

3 Background Radiation Emission or transmission of energy in form of waves or particles Its importance becomes intensified at high temperature No medium required Radiative physical property depends on surface roughness, material, thickness of coating, temperature, angle, etc.

4 RADIATIVE HEAT TRANSFERRADIATIVE EQUILIBRIUM BLACKBODY DEFINITION… 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. PERFECT EMITTER IN EACH DIRECTION AND AT EVERY WAVE LENGTH 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. PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

5 RADIATIVE HEAT TRANSFERRADIATIVE EQUILIBRIUM HEMISPHERICAL SPECTRAL EMISSIVE POWER OF BLACKBODY FOR SEVERAL DIFFERENT TEMPERATURES Wien’s (Displacement) Law : πœ†π‘‡=π‘π‘œπ‘›π‘ π‘‘π‘Žπ‘›π‘‘ Plank’s Distribution Law : 𝐸 π‘πœ† = 2β„Ž 𝑐 2 πœ† 𝑒 β„Žπ‘ πœ†π‘˜π‘‡ βˆ’1 PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

6 RADIATIVE HEAT TRANSFERGAS RADIATION ATTENUATION BY EARTH’S ATMOSPHERE OF INCIDENT SOLAR SPECTRAL ENERGY FLUX PROPULSION AND COMBUSTION LABORATORY RADIATIVE HEAT TRANSFER

7 Background Fluorescence - - + External energy hits the electronElectron goes to higher orbital Elevated electron comes back to original orbital for a brief time Unique wavelength is emitted N=3 Unique wavelength N=2 - N=1 - + Energy 𝐸 π‘β„Žπ‘œπ‘‘π‘œπ‘› =β„Žπ‘£ (𝐸:π‘’π‘›π‘Ÿπ‘”π‘¦ π‘œπ‘“ π‘β„Žπ‘œπ‘‘π‘œπ‘›, 𝑣 :π‘“π‘Ÿπ‘’π‘žπ‘’π‘’π‘›π‘π‘¦, β„Ž :π‘ƒπ‘™π‘Žπ‘› π‘˜ β€² 𝑠 π‘π‘œπ‘›π‘ π‘‘π‘›π‘Žπ‘‘)

8 Background IncandescenceRadiation from a hot body as a result of high temperature Thermal radiation Weak intensity in visible spectrum at low temperature

9 Experimental setup Specification Model name USB2000+VIS-NIR Dimensions89.1*63.3*34.4 mm Detector Sony ILX511B (2048-element linear silicon CCD array) Detector range nm Best efficiency(>30%) nm Optical resolution ~ nm (configuration dependent)

10 Experimental setup Operation principle (Optional) (Optional) 4 8 6 7 910 3 5 2 (Optional) 1 (Optional)

11 Experimental setup Spectrometer Dark room Computer Optical fiberRadiation Computer Optical fiber 400 Β΅m

12 Objectives Purpose of experiment 2nd week 1st weekObservation of spectral radiation from light source Analysis of unique wavelength 1st week 2nd week Observation of spectral radiation from fluorescent lamp Observation of spectral radiation from incandescent lamp and Sun Estimation of the temperature