Takeshi Kunitomo

Experimental studies of the radiative properties of sulfur dioxide

Abstract The narrow band-model parameters S/d, γN/d and B have been obtained experimentally for the infrared bands of SO2. Good agreement was obtained between the present experimental and previous theoretical studies. The revised wide band-model parameters were determined and used to calculate total gas emissivities, which are found to be considerably different from previously published values.

Narrow band model parameters for the CO2 4·3 μm band

Abstract The narrow band model parameters of the carbon dioxide 4·3 μm band have been obtained from absorption experiments with four broadening gases, namely CO, N 2 , O 2 , and Ar. The temperature and wave number dependence of the parameters are discussed. The experiments were performed at temperatures of about 303, 598 and 1185°K, with CO 2 partial pressures between 0·01 and 1·0 atm, at a total pressure of 1·0 atm. The Elsasser and the statistical models were applied to thebands in order to obtain applicable parameters and to determine a suitable model for the band at each temperature. It has been found that the Elsasser model is an adequate representation of the band at low temperatures whereas the statistical model is preferred at elevated temperatures. The effect on the line half-widths of the broadening gases is discussed. Good agreement is obtained between absorptance calculated with the present parameters and experimental results obtained by other authors.

Emissivity and band-model parameters for infrared bands of nitrous oxide

Abstract Narrow band-model parameters S/d, γN/d and B have been obtained experimentally for the v3, v1 and 2v2 bands of N2O in the temperature range from 200°K to 500°K. The exponential-wide band-model parameters have been determined for all of the contributing bands and have been found to differ greatly from the values of Tien et al. Data of revised total gas emissivities are presented.

Line-shape parameters in infrared bands of sulfur dioxide

This paper presents the calculated results for line-shape parameters in the v1 and v3 bands of sulfur dioxide for temperatures between 300 and 1200°K, together with the self-broadening coefficients for some particular rotational lines. The Anderson-Tsao-Curnutte theory was applied to calculate the line half-widths, and a criterion was introduced to determine the line-shape parameters on the basis of a narrow-band model. The calculated results are greatly different from previously assumed values.

Calculation of absorption coefficient for the ν2 and ν3 bands of sulfur dioxide

Abstract Absorption coefficients S / d of sulfur dioxide were calculated in the ν 2 and ν 3 bands for a temperature range from 300 to 1200°K. Calculations were carried out for such vibrational transitions that their integrated absorption coefficients α at T °K are greater than 0.1% of the total integrated absorption coefficients α obs observed at 300°K. Rotational lines with intensities greater than 10 -6 cm -2 atm -1 STP were included in the calculation. The line intensities were averaged over small wavenumber intervals of Δω = 10 cm -1 throughout the bands to obtain the absorption coefficients S / d . They were compared with the experimental values of other investigators and good agreement was obtained.

Calculation of absorption coefficient for the ν1 band of sulfur dioxide

Abstract The absorption coefficients S / d of sulfur dioxide have been calculated for the ν 1 band for temperatures from 300 ∼ 1500°K, taking the major isotopic species S 34 O 2 into consideration. The total number of the vibrational transitions considered were 4, 10, 23, 41 and 70 for the temperatures of 300, 600, 900, 1200 and 1500°K, respectively. The vibrational energy was calculated to the second order, and the rotational energy and matrix element were calculated exactly with consideration for the asymmetry of the sulfur dioxide molecule. The line intensities greater than 1·0 × 10 -8 cm -2 atm -1 STP were included in the calculations. The wavenumber regions of 1000 ∼ 1300 cm -1 were divided into small intervals of Δω = 10 cm -1 and the S / d averaged over the Δω were obtained. The S / d and some of the line intensities and positions at 300°K were compared with the experimental results of other workers and good agreement was obtained.

Optimization and heat transfer for the vertical fin array on isothermal and nonisothermal plane surface under conbined natural convection and radiation.

自然対流ふく射同時熱伝達下のフィン付平面放熱器に関して自然対流ふく射複合伝熱解析をもとに,まず,基板温度が一様な場合についてフィン体積さらにはフィン占有体積をも評価した目的量に関して最適計算を行ない,最適形状(フィン数,フィン間隔,フィン高さ,フィン厚み)を明らかにした.つぎに,基板の一部のみが等温である場合についての伝熱解析手法を提案し,実験との比較によりその有用性を明らかにした.

Experimental investigation for the circular and longitudinal fins on a tube under combined radiation and conduction.

円形および縦フイン付円管放熱器に関して,真空容器内でふく射伝熱実験を行い,相互ふく射を考慮したフイン列のふく射伝導伝熱の解析結果と有効度,フイン温度分布について比較した.円形フインの場合は両端フインの放熱量が大きいために系全体の有効度では計算結果より20～30%高いが系の中央部では有効度温度分布ともに良好な一致をみた.縦フインの場合は系全体の有効度で高温領域の4～5%の偏差を最大とする一致を得た.

OPTIMUM DESIGN PARAMETERS OF HORIZONTAL COAXIAL CYLINDERS FOR A SOLAR ENERGY COLLECTOR

ABSTRACT In this paper, the optimum combinations of the design parameters of a solar collector system for thermal use of horizontal coaxial cylinders with a cylindrical parabolic mirror are discussed from the standpoint of exergy, collector efficiency and outlet temperature of a fluid. Heat balance calculation is carried out, using the exact relations of simultaneous radiative, convective and conductive heat tranfer in the system.