Determination of Planck Mean Absorption Coefficients for HBr, HCl, and HF

2001 ◽  
Vol 124 (1) ◽  
pp. 26-29 ◽  
Author(s):  
S. P. Fuss ◽  
A. Hamins
Keyword(s):  
Absorption Coefficient ◽  
Narrow Band ◽  
Band Model ◽  
Absorption Coefficients ◽  
Temperature Range ◽  
Average Value ◽  
Integrated Intensity ◽  
Using Data ◽  
Narrow Band Model

The Planck mean absorption coefficient, ap, has been calculated for HBr, HCl, and HF over a temperature range from 300 K–2300 K using data from the 1996 edition of the HITRAN molecular database. Plots of ap versus temperature showed monotonically decreasing behavior over this temperature range, with peak values at 300 K of 45.9 (atm-m)−1, 5.3 (atm-m)−1, and 1.95 (atm-m)−1 for HF, HCl, and HBr, respectively. The magnitude of these values suggests that HBr, HCl, and HF can significantly impact calculations of radiative transfer in flames containing these species. Two sets of additional calculations were performed for CO to validate the methodology used for calculation of ap for HBr, HF, and HCl. In the first approach, which employed the narrow band model RADCAL, the calculation procedure was similar to that of the present calculations. The second approach utilized tabulated values of the integrated intensity for each CO band and an average value of the Planck function within each band. Results from the three methods showed general agreement. Polynomial expressions are provided as fits to ap as a function of temperature for HBr, HCl, HF, and CO.

Theoretical and Computational Research of Heat Radiant Transfer in Cylinder

2014 ◽  
Vol 628 ◽  
pp. 311-316
Author(s):  
Hua Xiang Zhou ◽  
Zheng Zhou ◽  
Jing Ping Liu
Keyword(s):  
Heat Transfer ◽  
Absorption Coefficient ◽  
Calculation Method ◽  
Narrow Band ◽  
Radiation Heat Transfer ◽  
Band Model ◽  
Calculation Methods ◽  
Radiation Heat ◽  
Heat Transfer Theory ◽  
Narrow Band Model

In order to obtain the radiation heat transfer theory and calculation methods, the movement of the gas particles, location, intensity, temperature, are researched in cylinder under different conditions with combustion system and the mode of heat transfer. Under high temperature conditions in the cylinder, the gas radiation heat transfer is researched in the complex heat transfer theory. A statistical correlation K narrow band model, a mean absorption coefficient, a gas line databases, by-line calculation method are found, through research and analysis emissivity, transmittance, absorption coefficient, typical models, mathematical equations, database, calculation methods. Examine the distribution performance of each database for different media concentration and temperature, a statistical narrow-band band parametric model accuracy is tested, using statistical narrow band model, the results of the use of by-line method. Research shows: selected spectral database, calculation method has a greater impact on the results. The research also shows the result coincides calculations based by-line HITEWP2010 database method, whether radiant heat or wall flux, statistical narrow band model. These are supplied to the internal combustion engine cylinder design.

Thermal Radiation Properties of Acetylene

1985 ◽  
Vol 107 (4) ◽  
pp. 943-948 ◽  
Author(s):  
M. A. Brosmer ◽  
C. L. Tien
Keyword(s):  
Absorption Coefficient ◽  
Thermal Radiation ◽  
Narrow Band ◽  
Wide Band ◽  
Band Model ◽  
Radiation Properties ◽  
Wide Band Model ◽  
Combination Bands ◽  
Total Emissivity

The spectral absorptivities of the ν3 and ν5 fundamental and the ν4 + ν5 combination bands of acetylene have been measured at low resolution for temperatures between 290 and 600 K. These measurements allow the determination of spectral-mean (narrow-band) parameters for the three bands based on the Elsasser and Goody models and the correlation of the band absorptance data using the Edwards exponential wide-band model. Charts for the total emissivity and Planck mean absorption coefficient have been developed for acetylene based on the wide-band parameters.

The Use of Reverse Mirage Spectroscopy to Determine the Absorption Coefficient of Liquid Methanol at CO2 Laser Wavelengths

1989 ◽  
Vol 43 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Dane Bićanić ◽  
Siegfried Krüger ◽  
Paul Torfs ◽  
Bruno Bein ◽  
Frans Harren
Keyword(s):  
Absorption Coefficient ◽  
Co2 Laser ◽  
Probe Beam ◽  
Laser Emission ◽  
Wavelength Region ◽  
Experimental Setup ◽  
Absorption Coefficients ◽  
Experimental Conditions ◽  
Liquid Samples

An experimental setup for performance of reverse mirage spectroscopy at CO2 laser wavelengths on liquid samples having high values of absorption coefficients is described. One and the same liquid is used as both the absorbing and deflecting medium. The Rosencwaig-Gersho theory has been applied, and the choice of experimental conditions that would enable determination of absorption coefficient β from the magnitude of photothermal signals measured at two different probe beam distances (probing locations) is discussed. The usefulness of this technique (essentially not inhibited by the requirements imposed on the sample's thickness) is tested on methanol having absorption coefficients β close to 300 cm−1 in the wavelength region covered by CO2 laser emission.

Narrow-band model

1977 ◽  
Vol 12 (4) ◽  
pp. 211-212
Author(s):  
J W Warren ◽  
B K Tanner
Keyword(s):  
Narrow Band ◽  
Band Model ◽  
Narrow Band Model

Narrow-band model revisited

1976 ◽  
Vol 11 (7) ◽  
pp. 452-453
Author(s):  
B K Tanner
Keyword(s):  
Narrow Band ◽  
Band Model ◽  
Narrow Band Model

THE NORMAL STATE HALL EFFECT IN NdBa2-xLaxCu3O7-δ: EVIDENCE FOR HOLE LOCALIZATION BY LA DOPING

2009 ◽  
Vol 23 (31) ◽  
pp. 5779-5788
Author(s):  
S. R. GHORBANI ◽  
F. ABRINAEY
Keyword(s):  
Critical Temperature ◽  
Hall Effect ◽  
Hall Coefficient ◽  
Normal State ◽  
Doping Concentration ◽  
Narrow Band ◽  
Band Model ◽  
Measured Temperature ◽  
Temperature Range ◽  
La Doping

The transport properties of sintered samples of NdBa 2-x La x Cu 3 O 7-δ with 0 ≤ x ≤ 0.3 have been studied in the normal state by Hall effect measurements. The Hall coefficient, RH is positive in the normal state and increases with increasing La doping concentration over the whole temperature range from the critical temperature, Tc, up to room temperature. The results for the Hall coefficient as a function of temperature and doping concentration were analyzed within the phenomenological narrow band and Anderson models. A good agreement between models and data was obtained. As in the phenomenological narrow band model, the band widths increase with increasing doping concentration. As in the Anderson model, the Hall angle is proportional to T2 over the whole measured temperature range for all samples. The obtained results for both models supported the view that La doping introduces electronic disorder into the CuO 2 planes. The tendency towards localization is driven by electronic disorder. In addition to hole filling, the localization is another reason for the decreasing superconducting critical temperature in these samples.

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