Page 194 - Mechanical Engineers' Handbook (Volume 4)

3 Radiation Heat Transfer 183

Table 16 Radiation Function F o- T
T T T
m K m R F o- T m K m R F o- T m K m R F o- T
400 720 0.1864 10 11 3400 6120 0.3617 6400 11,520 0.7692
500 900 0.1298 10 8 3500 6300 0.3829 6500 11,700 0.7763
600 1080 0.9290 10 7 3600 6480 0.4036 6600 11,880 0.7832
700 1260 0.1838 10 5 3700 6660 0.4238 6800 12,240 0.7961
800 1440 0.1643 10 4 3800 6840 0.4434 7000 12,600 0.8081
900 1620 0.8701 10 4 3900 7020 0.4624 7200 12,960 0.8192
1000 1800 0.3207 10 3 4000 7200 0.4809 7400 13,320 0.8295
1100 1980 0.9111 10 3 4100 7380 0.4987 7600 13,680 0.8391
1200 2160 0.2134 10 2 4200 7560 0.5160 7800 14,040 0.8480
1300 2340 0.4316 10 2 4300 7740 0.5327 8000 14,400 0.8562
1400 2520 0.7789 10 2 4400 7920 0.5488 8200 14,760 0.8640
1500 2700 0.1285 10 1 4500 8100 0.5643 8400 15,120 0.8712
1600 2880 0.1972 10 1 4600 8280 0.5793 8600 15,480 0.8779
1700 3060 0.2853 10 1 4700 8460 0.5937 8800 15,840 0.8841
1800 3240 0.3934 10 1 4800 8640 0.6075 9000 16,200 0.8900
1900 3420 0.5210 10 1 4900 8820 0.6209 10,000 18,000 0.9142
2000 3600 0.6673 10 1 5000 9000 0.6337 11,000 19,800 0.9318
2100 3780 0.8305 10 1 5100 9180 0.6461 12,000 21,600 0.9451
2200 3960 0.1009 5200 9360 0.6579 13,000 23,400 0.9551
2300 4140 0.1200 5300 9540 0.6694 14,000 25,200 0.9628
2400 4320 0.1402 5400 9720 0.6803 15,000 27,000 0.9689
2500 4500 0.1613 5500 9900 0.6909 20,000 36,000 0.9856
2600 4680 0.1831 5600 10,080 0.7010 25,000 45,000 0.9922
2700 4860 0.2053 5700 10,260 0.7108 30,000 54,000 0.9953
2800 5040 0.2279 5800 10,440 0.7201 35,000 63,000 0.9970
2900 5220 0.2505 5900 10,620 0.7291 40,000 72,000 0.9979
3000 5400 0.2732 6000 10,800 0.7378 45,000 81,000 0.9985
3100 5580 0.2958 6100 10,980 0.7461 50,000 90,000 0.9989
3200 5760 0.3181 6200 11,160 0.7541 55,000 99,000 0.9992
3300 5940 0.3401 6300 11,340 0.7618 60,000 108,000 0.9994

G Gd

0
As was the case for the wavelength-dependent parameters, the sum of the total reflectivity,
total absorptivity, and total transmissivity must be equal to unity, i.e.,
1

It is important to note that while the emissivity is a function of the material, temperature,
and surface conditions, the absorptivity and reflectivity depend on both the surface charac-
teristics and the nature of the incident radiation.
The terms reflectance, absorptance, and transmittance are used by some authors for the
real surfaces and the terms reflectivity, absorptivity, and transmissivity are reserved for the
properties of the ideal surfaces (i.e., those optically smooth and pure substances perfectly
uncontaminated). Surfaces that allow no radiation to pass through are referred to as opaque,