1.

論文

論文
中村, 卓人 ; 小林, 佳弘 ; 古畑, 朋彦 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  75  pp.1363-1370,  2009-06-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Nano meter size particulate matter (nano-PM) and polycyclic aromatic hydrocarbons (PAHs) have harmful effects for human health. It was thought that PAHs were a precursor of nano-PM. Then fundamental information of PAHs behavior in combustion process has been required to establish reduction technologies for nano-PM emission. In this paper, PAHs concentration, PM composition, and number concentration of PM in diffusion flames of methane (CH_4) and propane (C_3H_8) were investigated. As the result, benzene and toluene formed from fuel (methane or propane) had the two peaks at upstream and at downstream of PAHs-soot transition region in the flames. Moreover, concentration of PAHs formed from propane was higher than that formed from methane. In addition, both of soot and SOF compositions in PM formed from propane flame showed higher concentrations than those in methane flame. 続きを見る
2.

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論文
小林, 佳弘 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  75  pp.184-191,  2009-01-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Nano meter size particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) have harmful effects for human health. Investigations of the fundamental characteristic of PAHs behavior in combustion process were required for the establishment of the reduction technologies for nano-PM emission. In this paper, PAHs characteristics in diffusion flames of propane gas were investigated using laser diagnostic and gas sampling methods. A laser induced fluorescence (LIF) method was used to obtain the spatial distributions of PAHs. Spatial distributions of soot were also measured by a laser induced incandescence (LII) method. A transition region from PAHs to soot was defined from the results of LIF and LII. Further, PAH concentrations in the test flames were measured using a gas chromatography (GC), and the profiles of PAHs concentrations in the test flames were investigated. As the results, heavier molecules PAHs such as fluorene and pyrene were confirmed as precursors of soot. 続きを見る
3.

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論文
小林, 佳弘 ; 天谷, 賢児 ; 古畑, 朋彦 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  74  pp.475-481,  2008-02-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />In this study, formation mechanisms of PM (particulate matter) and its precursor (PAHs (polycyclic aromatic hydrocarbons)) were investigated as a fundamental PM study of diesel fuel combustion. A laminar diffusion flame of diesel fuel at a small pool-wick combustion equipment was used as the test flame. Spatial distributions of PAHs and soot in the flame were measured by a laser induced fluorescence (LIF) and a laser induced incandescence (LIT) methods. Emission spectra of PAHs fluorescence were analyzed by a spectroscope. Since the peak wavelength of the LIF spectrum of PAHs could be described as a function of the carbon number of PAHs, the molecular size of PAHs could be estimated. PAH species in the flame were measured using a gas chromatography (GC). LIF and GC data were compared for understanding the transition behavior from PAH to soot. These results suggested that the PAHs molecules rapidly grew up to the soot particles at nucleation area of PM. It was confirmed that relatively small PAHs species such as benzene and toluene existed in sooting region, however, the larger PAHs such as fluorine and pyrene could not be observed in the sooting region. 続きを見る
4.

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論文
小林, 佳弘 ; 斉藤, 孝充 ; 天谷, 賢児 ; 古畑, 朋彦 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  72  pp.1835-1842,  2006-07-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Since the engine combustion is affected by a variety of parameter such as well as fuel characteristics, it is very difficult to find out the clear effect of fuel property. In order to clarify the change of emission characteristic caused by fuel change, we propose a fundamental flame research method using a small pool-wick flame system. By using this system, PAHs (polycyclic aromatic hydrocarbons) formation mechanism in a flame was investigated as a fundamental study of diesel combustion. Characteristics of PAHs formation in a laminar diffusion flame were measured by a laser induced fluorescence (LIF) method. It was compared with PM charactersistics measured by a laser induced incandescence (LII) method. The effect of the lubricating oil contamination on the PAHs distributions in the flame was discussed. As the result, it was found that the PAHs concentration in the flame increased with increasing the lubricating oil contamination and it caused the increase of PM formation in the flame. 続きを見る
5.

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論文
HAYASHIDA, Kazuhiro ; AMAGAI, Kenji ; SATOH, Keiji ; ARAI, Masataka
出版情報: JSME international journal. Ser. B, Fluids and thermal engineering.  49  pp.512-519,  2006-05-15.  社団法人日本機械学会
概要: application/pdf<br />Journal Article<br />Spontaneous Raman spectroscopy with KrF excimer laser was applied to obtain a fuel concentration distribution in a sooting flame. In the case of sooting flame, fluorescence from polycyclic aromatic hydrocarbons (PAH) and laser-induced incandescence (LII) from soot particles appeared with Raman scattering. These background emissions overlapped on the Raman scattering. In order to separate the Raman scattering and the background emissions, polarization property of laser-induced emissions was utilized. Since the background emissions were depolarized whereas the Raman scattering was highly polarized, it is possible to subtract the background emissions from the overlapping signal of the Raman scattering and the background emissions. Subtracting the emission signals for the electric vector of the laser light perpendicular and parallel to the direction of observation allows to extract the precise Raman signals. By using this technique, detailed fuel concentration distribution in sooting flames could be obtained based on Raman scattering. 続きを見る
6.

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論文
石井, 哲人 ; 佐藤, 博之 ; 天谷, 賢児 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  72  pp.194-201,  2006-01-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />The effects of gravity on the fluctuation characteristics of turbulent diffusion flames were experimentally investigated. Super gravity fields were formed using a spin tester. The gravity level G was changed from 1 to 20, where G was defined as the value of super gravity per normal gravity. Flame states such as laminar, flickering and turbulent flames were observed under the various conditions of gravity level, G and Reynolds number, Re. The transition from laminar to turbulent and blow out limit were summarized on a G-Re map. Characteristics of turbulent fluctuation were measured by a laser light reflection method. Power spectra and auto-correlations were derived from the signal of laser intensity. As the result, it was found that the turbulent flame was begun to periodic oscillation with increasing the gravity level. Time scale of turbulent fluctuation in the super gravity became long than that in the normal gravity. Spectrum component in power spectrum shifted to the low frequency side when the gravity level became high. And the full width at half-maximum of autocorrelation peak became wider in the super gravity conditions. 続きを見る
7.

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論文
林田, 和宏 ; 天谷, 賢児 ; 佐藤, 桂司 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  71  pp.1445-1452,  2005-05-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Raman scattering technique with KrF excimer laser was applied to obtain a fuel concentration distribution in a sooting flame. In the case of sooting flame, fluorescence from polycyclic aromatic hydrocarbons (PAH) and laser-induced incandescence (LII) from soot particles appeared with Raman scattering. These background emissions overlappped on the Raman scattering. In order to separate the Raman scattering and the background emissions, polarization property of laser-induced emissions was utilized. Since the background emissions were depolarized whereas the Raman scattering was highly polarized, it is possible to subtract the background emissions from the overlapping signal of the Raman scattering and the background emissions. Subtracting the emission signals for the electric vector of the laser light perpendicular and parallel to the direction of observation allows to extract the precise Raman signals. By using this technique, detailed fuel concentration distribution in sooting flames could be obtained based on Raman scattering. 続きを見る
8.

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論文
佐藤, 桂司 ; 林田, 和宏 ; 宮川, 拓 ; 天谷, 賢児 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  70  pp.2183-2190,  2004-08-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Laser induced fluorescence (LIF) method was applied to the measurement of PAHs (Polycyclic Aromatic Hydrocarbons) in a propane diffusion flame. Various PAHs were excited by a KrF excimer laser and a dye-laser pumped by the XeF excimer laser. By measuring the enission spectra of various PAHs vapors, it was found that the peak wavelength in the emission spectrom of LIF shifted to the longer wavelength side with an increase of PAHs carbon numbers. The carbon numbers of PAHs in a diffusion flame was presumed from the data of peak wavelength of emission spectrum. It was confirmed that the carbon numbers of PAHs in the diffusion flame increased as approaching to the flame surface. The maximum carbon number was about 26 at the layer close to the flame surface. 続きを見る
9.

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論文
林田, 和宏 ; 天谷, 賢児 ; 白井, 紘行 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  70  pp.1834-1841,  2004-07-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />LIF thermometry in a sooting diffusion flame was newly proposed based on a spe ctral matching method. A tunable ArF excimer laser was used to excite the several absorption lines in the D^2Σ^+←X^2II(0, 1) band system of NO. In the case of sooting diffusion flame, emission spectrum consisted of NO and O_2 fluorescence, and off-resonance emissions related to the soot. The O_2 fluorescence and the off-resonance emissions overlapped on the NO fluorescence. However, the offresonance emissions near the vacuum ultraviolet region (VUV) were weaker than the NO fluorescence, and the ε(0, 3) band of the NO fluorescence, which appeared near the VUV region, was free from the O_2 fluorescence. Therefore, NO rotational temperature in a sooting diffusion flame could be measured by the spectral matching method using the ε(0, 3) band. By using this technique, NO rotational temperature in a propane diffusion flame could be measured. 続きを見る
10.

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論文
佐藤, 桂司 ; 林田, 和宏 ; 天谷, 賢児 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  70  pp.1051-1057,  2004-04-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />In this paper, separation of laser-induced fluorescence (LIF) due to PAHs and incandescence (LII) due to soot by time-resolved measurement was demonstrated for the propane diffusion flame. Laser-induced fluorescence method for the measurement of polycyclic aromatic hydrocarbons (PAHs) in diffusion flame was developed. A KrF excimer laser was used for excite the PAHs. Strong laser-induced incandescence due to soot was appeared with fluorescence signal due to PAHs. In order to separate the signals into LII and the PAHs-LIF detected from diffusion flame, time-resolved measurement was carried out. A pico-second gate CCD camera with a image intensifier was used taking a time-resolved image. From the two different images, which were taken at different time-delay, PAHs-LIF and LII were obtained. Intensity distributions of PAHs-LIF and LII were measured on the flame axis. Overlap region of the LIF and LII was observed around the onset position of the yellow flame. In this region, LIF intensity decreased and LII intensity increased along the flow direction. It seemed that this region was transition region from the PAHs to soot and was attributed the presence of soot precursor. 続きを見る
11.

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論文
HAYASHIDA, Kazuhiro ; SHIRAI, Hiroyuki ; AMAGAI, Kenji ; ARAI, Masataka
出版情報: JSME international journal. Ser. B, Fluids and thermal engineering.  45  pp.201-208,  2002-02-15.  社団法人日本機械学会
概要: application/pdf<br />Journal Article<br />Rotational temperature of NO molecule in methane/air premixed flame was estima ted by a spectral matching method. A tunable narrow band ArF excimer laser was used to excite the D^2Σ^+ ← X^2∏(0,1) band system of NO. Laser beam was introduced in a flame, and the laser-induced fluorescence was resolved into a spectrum by using a spectrograph. On this spectrum, e and δ bands of upper vibrational level of v'=0 were analyzed. In order to use a spectral matching method, profiles of ε and δ band spectra were calculated theoretically in detail with reliable molecular constants and exact equations, and they were modulated by an experimental slit function. Since the profile of band spectrum was determined as a function of a rotational temperature, a rotational temperature could be estimated using the temperature where the profile of every band spectrum obtained theoretically is fitted to that of experimentally obtained. Applying a spectral matching method on the ε(0,3), ε(0,4) and δ(0,2) band of NO, it was obtained that the rotational temperature is about 1000 K. The obtained rotational temperature is almost agreed with the thermocouple temperature. 続きを見る
12.

論文

論文
佐藤, 博之 ; 天谷, 賢児 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  67  pp.2820-2827,  2001-11-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Effect of gravity level on the flickering motion was experimentally investigat ed for the propane and propane-hydrogen jet diffusion flames. A centrifuge was used for quantitative measurement of gravity effect, and frequency analysis was performed for the flickering flames. From the result of measurements under various gravity levels, it was clarified that the flickering frequency increased with an increase in the gravity level and it was correlated with two relationships expressed by the Strouhal number and the Froude number. One relationship was St∝Fr^<-0.41> for high Froude numbers (Fr≥100), and the other was St∝Fr^<-0.50> for low Froude numbers (Fr≤100). It meant that the Froude number gave the criterion of the flickering behavior and that flickering frequencies expressed by these two equations were affected by buoyancy in different ways. From the frequency analysis, it was found that oscillations of a flickering flame and a thermal convection around the flame were linked, but the characteristic of each flickering motion was different in the stability of periodicity. 続きを見る
13.

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論文
坂下, 直己 ; 天谷, 賢児 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  67  pp.2590-2595,  2001-10-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Fuel droplet and vapor distributions in a spray flame formed in the hot air stream were measured by an exciplex fluorescence method. Kerosene was used as a test fuel. Kerosene was miscible with a small quantity of exciplex-forming dopants, TMPD (N, N, N', N'-tetramethyl-1,4-phenylene diamine) and naphthalene. A Nd : YAG laser (355nm) was used for excitation of the fuel. The fuel spray was injected from a swirl atomizer into an air stream. Air temperature was changed from room temperature to 1000k which was higher than the self-ignition temperature of a kerosene spray. Distributions of the fuel droplets and vapor were strongly affected by the air temperature. Furthermore it was confirmed that the fuel vapor was transported into recirculating flow area formed on the flame holder. 続きを見る
14.

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論文
佐藤, 博之 ; 天谷, 賢児 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  67  pp.2596-2603,  2001-10-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Quantitative investigation of the gravity effect was performed for acetone and kerosene pool fires. A centrifuge was used to examine the gravity effect. Small-scale pool fires were observed under various high gravity fields. Regions of stable flame, puffing flame and irregular oscillatory flame were mapped with the gravity level and pool diameter. Flame height decreased and oscillatory frequency increased with an increase in the gravity level. Behavior of the flame height was agreed quantitatively with the scaling prediction presented by Orloff and Heskestad. Puffing phenomena observed under various gravity fields were summarized with the Strouhal number and Froude number. As the result, we could obtain an empirical equation of St=0.517Fr^<-0.502>. From this equation, puffing frequency could be estimated for a flame of various pool diameter varying from 0.01 to 50 meters. 続きを見る
15.

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論文
茂木, 俊夫 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  67  pp.522-528,  2001-02-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Fundamental characteristics of the catalytic combustion of vaporized kerosene spray were studied experimentally. Palladium catalyst supported on the cordierite honeycomb monolith was used. Inlet temperature was elevated up to 700 K to evaporate the kerosene spray. Premixed gas of air and kerosene vapor was introduced into the catalyst. The catalytic combustion and gas phase reaction after catalyst were observed in this combustion system. The lean limit of the catalytic combustion was not affected by the space velocity and equivalence ratio of the mixture, but it was greatly affected by the inlet temperature. The parabolic shape blue flame that was supported on the catalyst was formed when the supplied mixture was not completely burned in the monolith. To clarify a reaction process in an combustive gas between the monolith and the blue flame, CO, HC(C_1~C_7) and NO were analyzed. When the blue flame was observed after the catalyst, the HC and CO were formed from the unburned composition of fuel and they were burned as the blue flame. The NO emission level of the catalytic combustion was very low compared with the gas phase reaction of lean mixture. 続きを見る
16.

論文

論文
林田, 和宏 ; 白井, 紘行 ; 天谷, 賢児 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  66  pp.3013-3020,  2000-11-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Rotational temperature of NO molecule in methane/air premixed flame was estima ted by a spectral matching method. A tunable narrow band ArF excimer laser was used to excite the D^2Σ^+(ν′=0)←X^2Π(ν""=1) band system of NO. Laser beam irradiated a flame, and the laser induced fluorescence was resolved into a spectrum by using a spectroscope. On this spectrum, ε and δ bands of upper vibrational level of ν′=0 were analyzed. In order to use a spectral matching method, profiles of ε and δ band spectra were calculated theoretically in detail with reliable molecular constants and exact formula, and they were modulated by an experimental slit function. Since the profile of band spectrum was determined as a function of a rotational temperature, a rotational temperature could be estimated from the temperature where the profile of every band spectrum obtained theoretically is fitted to that of experimentally obtained. Applying a spectral matching method on the ε(0, 3), ε(0, 4) and δ(0, 2) band of NO, it was obtained that the rotational temperature is about 1000K. Obtained rotational temperature is almost agreed with a thermocouple temperature. 続きを見る
17.

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論文
長谷川, 和之 ; 茂木, 俊夫 ; 天谷, 賢児 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  65  pp.3831-3837,  1999-11-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Behavior of a spray combustion in a hot air was studied experimentally. A kerosene spray was injected from swirl atomizer into a hot air stream. The air temperature was controlled from room temperature to 1 100 K which was higher than the self-ignition temperature of a kerosene spray. Flame shape and temperature distribution were measured to characterize the spray combustion appeared in the hot air stream. Flow state around the spray was visualized by a Schlieren method to analyze the behavior of the air entrainment into the flame. Furthermore, Mie scattering from the spray droplets by irradiation of the laser beam was observed to visualize the spray concentration in a flame. As the result, ignition point was shifted to the upstream side with an increase of air temperature. When the air temperature became higher than 800 K, the blue flame appeared at the bottom portion of the flame. Penetration of the spray became shorter with an increase of air temperature. Spatial distribution of the spray which were not vaporized in a flame was strongly affected by the air temperature. 続きを見る
18.

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論文
佐藤, 博之 ; 天谷, 賢児 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  65  pp.1786-1792,  1999-05-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Flame lengths of gas jet diffusion flames were measured under various gravity evels. A spin tester was used to obtain a high gravity field which level was changed from normal gravity (G=1) to G-20. In order to investigate the fuel density effect on flame structure at high gravity level, two kinds of fuels (methane and propanw) and further methane-propane mixture fuel whose density was equivalent to the surrounding air were used. As the results, flame length decreased with an increase of gravity level regardless of the positive and negative buoyancy effect between the fuel and surroundings. To investigate the gravity effect on flame structure, length of blue flame which appeared at anchor portion of the flame was measured under various gravity levels. It was confirmed that the blue flame was expanded with an increase of the gravity level. This result was explained by the enhancement of the air entrainment at the anchor portion of the flame. Evaluation of flame length which was obtained by Altenkirch considering the relationship of fuel and required oxygen were used to evaluate the experimental data of flame length under the various gravity level. From this method the following empirical correlation was proposed : L_f/γ_o=1.72Re^<0.667>Fγ^<0.0846>, where L_f is a flame length, γ_o is a nozzle radius, Re is the Reynolds number based on nozzle radius and Fγ is the Froude number. 続きを見る
19.

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論文
新居, 利洋 ; 斉藤, 正浩 ; 新井, 雅隆
出版情報: 日本機械学會論文集. B編.  64  pp.3881-3887,  1998-11-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />This paper reports the suppression of soot emission from acetylene diffusion flame by applying electric field. The effects of applied voltage, polarity and spacing of electrodes on soot emission were investigated experimentally. The results showed that the shape of flame changed and the soot emission decreased with increasing the applied voltage. The polarity of applied voltage influenced to the shape of flame and the soot emission. When positive voltage was applied to the nozzle electrode, the flame length became short and the width at the flame tip was spread. And, more than 90% of soot emission was suppressed at over 200 kV/m of the intensity of electric field. The surface temperature of flame increased with increasing the applied voltage. Thus, it was considered that the increase of flame surface temperature promoted the soot oxidation. When negative voltage was applied to the nozzle electrode, on the contrary, only the 70% of soot emission was suppressed, because the flame temperature was comparable to that for non-applied voltage. 続きを見る
20.

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論文
ARAI, Masataka ; HIROYASU, Hiroyuki ; NAKAMORI, Kaoru ; NAKASO, Shinji
出版情報: JSME international journal. Ser. 2, Fluids engineering, heat transfer, power, combustion, thermophysical properties.  34  pp.540-547,  1991-11-05.  社団法人日本機械学会
概要: application/pdf<br />Journal Article<br />A new combustion system called a jet-mixing-type combustor was designed to obtain a nonluminous blue flame of a kerosene spray. A spray was injected by a conventional-type swirl atomizer into the combustor, and combustion air was introduced through a baffle plate with 16 inlet holes. The principle of this combustion method was revealed as a prompt mixing of the air and spray, which was achieved by high-speed air jets. The combustion characteristics such as combustion stability, temperature distribution and exhaust emissions were compared with a conventional swirler-type combustor. NO and THC emissions exhausted from nonluminous kerosene flame were at lower levels than those exhausted from the swirler-type combustor. 続きを見る
21.

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論文
吉田, 肇 ; 新井, 雅隆 ; 廣安, 博之 ; 横谷, 昌道
出版情報: 日本機械学會論文集. B編.  57  pp.2416-2420,  1991-07-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />High speed schlieren movies were taken for detailed observation of the physical structure of flames propagating in propane-air mixtures containing kerosene spray. Effects of an overall equivalence ratio and a mixture ratio of propane/kerosene to the total fuel on the structure were examined. Fractal analysis of the flame structure was also attempted. As a result, two typical flame structures were observed, into which flame structures were classified according to propane concentration. One consisted of droplets ignited successively, the other consisted of flame front propagating in the interdroplet propane-air mixture. In the latter, flame front had fractal character and its fractal dimension increased and decreased with the flame propagation velocity. 続きを見る
22.

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論文
新井, 雅隆 ; Saito, Kozo ; Altenkirch, Robert A.
出版情報: 日本機械学會論文集. B編.  57  pp.1893-1898,  1991-05-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />An experimental investigation of the boilover phenomenon for a liquid burning above a water sublayer indicates that boilover occurs when the boiling point temperature of a pure fuel is more than that of the water. In this situation, the fuel temperature near the fuel-water interface is somewhat limited by the presence of the boiling water and cannot reach the fuel boiling point. The boilover behavior of multicomponent fuels is similar to that of pure fuels. The temperature measurements at the onset of boilover for multicomponent fuels show that a fixed amount of superheat, 10K, exists in the water sublayer near the fuel-water interface. Onset time of water boiling was measured and compared with an estimated value that was derived by a simple analysis of unsteady conductive heat transfer. 続きを見る
23.

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論文
新井, 雅隆 ; 廣安, 博之 ; 中森, 薫 ; 中曽, 伸二
出版情報: 日本機械学會論文集. B編.  56  pp.3160-3166,  1990-10-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />A new combustion system called a jet-mixing-type combustor was designed to obtain a nonluminous blue flame of a kerosine spray. A spray was injected by a conventional-type swirl atomizer into the combustor and combustion air was introduced through a baffle plate with 16 inlet holes. The principle of this combustion method was revealed as a prompt mixing of the air and the spray, which was achieved by a high-speed air jet. The combustion characteristics such as combustion stability, temperature distribution and exhaust emissions were compared with a conventional swirler-type combustor. NO and THC emission levels exhausted from nonluminous kerosine flame were lower than those exhausted from the swirler-type combustor. 続きを見る
24.

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論文
吉田, 肇 ; 新井, 雅隆 ; 廣安, 博之
出版情報: 日本機械学會論文集. B編.  56  pp.2490-2496,  1990-08-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />The process of flame development in a spark-ignited propane-air mixture that contained kerosene spray was observed by a high-speed VTR. Flame areas were measured on the VTR and the process of flame development was shown as a change of flame area versus time from ignition. Propagation delay, which means a period between spark ignition and the start of rapid flame development, was defined. Effects of an overall equivalence ratio, a mixture ratio of propane/kerosene to the total fuel and spark energy on the propagation delay and development rate of a flame were studied. Each lean propane-air mixture had a suitable value of the mixture ratio of kerosene spray for the minimum propagation delay and maximum development rate of a flame. When the mixture ratio of propane to the total fuel was low, the propagation delay decreased as the spark energy increased. 続きを見る
25.

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論文
新井, 雅隆 ; 斎藤, 孝三 ; Altenkrich, R.A ; Evans, D.D.
出版情報: 日本機械学會論文集. B編.  56  pp.1775-1779,  1990-06-25.  日本機械学会
概要: application/pdf<br />Journal Article<br />Under certain circumstances, the water on which a burning pool of liquid fuel is supported may begin to boil. The bubble of water vapor that is released and escapes through the fuel surface tends to chenge the temperature distribution in the fuel layer and sometimes to atomize the fuel which results in a boilover of the burning liquid fuel. A pool fire system, in which the burning surface of the fuel was fed into the flame so that a boiling water sublayer could be oberved, was designed to invstigate the effect of water sublayer on the burning phenomena of the liquid fuel layer. Data obtained incrude temperature and mass loss history of the liquid fuel and water, flame hight, and irradiance from the flame. Results show that when boiling occurs, the temperature gradient across the fuel layer vanishes, the temperature level of the fuel decreases, and the burning rate of the fuel decreases. Because water-vapor bubbles released from the fuel-water interface stir the fuel layer as they pass upward through it. 続きを見る
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論文

論文
TABEI, Katsu'ine ; SHIRAI, Hiroyuki
出版情報: JSME international journal. Ser. 2, Fluids engineering, heat transfer, power, combustion, thermophysical properties.  33  pp.249-255,  1990-05-15.  社団法人日本機械学会
概要: application/pdf<br />Journal Article<br />A mathematical method for transforming moire-schlieren data into internal density (and/or temperature) distributions has been presented. The method of transformation, which is applicable to both symmetrical and asymmetrical flow fields, has been deduced by modifying the Maldonado-Olsen's series. The accuracy of the present method was examined with a mathematical model of a density function of the truncated pyramid type. In order to demonstrate its usefulness for asymmetrical flows, temperature distributions in a combustion flame have been measured for a square nozzle. Experimental moire images of the flame were recorded by a video camera, and the integrated light refraction was converted into an internal temperature distribution. The results showed that the temperature profiles in the flame are distinctive owing to the rectangular nozzle, and that the present method is very effective. 続きを見る