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| 1.
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中村, 卓人 ; 小林, 佳弘 ; 古畑, 朋彦 ; 新井, 雅隆
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
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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.
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| 2.
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林田, 和宏 ; 土師, 勝彦 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />In this study, effect of fuel properties on diffusion combustion of kerosene was investigated experimentally. Five types of kerosene, which distillation and composition properties were
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different, were used as the test fuel. Laminar diffusion flames of kerosene were formed by using wick combustion burner. Fuel consumption rate, flame temperature and flame luminosity of each flame were measured. As the results, fuel consumption rate proportionally increased with decreasing volume average boiling point, and both temperature and luminosity decreased as the aromatic content in the fuel increase. To investigate the effect on soot formation of fuel properties, concentration distributions of polycyclic aromatic hydrocarbons (PAHs) and soot were measured by laser-induced fluorescence (LIF) and laser-induced incandescence (LII). Both PAHs-LIF intensity on wick and LII intensity of soot emission increased with the content of aromatic compounds in the fuel became higher.
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| 3.
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小林, 佳弘 ; 新井, 雅隆
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
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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.
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| 4.
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小林, 佳弘 ; 天谷, 賢児 ; 古畑, 朋彦 ; 新井, 雅隆
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 fundamental characteristic of formation behavior of
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PAHs in combustion process were required for the reduction of nano-PM emission. In this paper, PAHs characteristics in diffusion flames of paraffin fuels were investigated using laser diagnostic and gas sampling methods. Methane (CH_4), propane (C_3H_8) and hexane (C_6H_<14>) were used as the test fuels. A laser induced fluorescence (LIF) method was used to obtain the spatial distributions of PAHs which were precursor molecules of soot. 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). Profiles of PAHs concentrations of test flames were compared. As the results, it was found that the low carbon number fuels such as propane and methane are remained to some fuel at downstream part. And, these some fuels were changed to large PAHs at downstream part.
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| 5.
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小林, 佳弘 ; 天谷, 賢児 ; 古畑, 朋彦 ; 新井, 雅隆
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
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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.
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| 6.
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小林, 佳弘 ; 斉藤, 孝充 ; 天谷, 賢児 ; 古畑, 朋彦 ; 新井, 雅隆
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
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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.
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| 7.
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HAYASHIDA, Kazuhiro ; AMAGAI, Kenji ; SATOH, Keiji ; ARAI, Masataka
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
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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.
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| 8.
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林田, 和宏 ; 天谷, 賢児 ; 佐藤, 桂司 ; 新井, 雅隆
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
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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.
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| 9.
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佐藤, 桂司 ; 林田, 和宏 ; 宮川, 拓 ; 天谷, 賢児 ; 新井, 雅隆
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
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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.
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| 10.
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林田, 和宏 ; 天谷, 賢児 ; 白井, 紘行 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />LIF thermometry in a sooting diffusion flame was newly proposed based on a spe
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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.
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| 11.
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佐藤, 桂司 ; 林田, 和宏 ; 天谷, 賢児 ; 新井, 雅隆
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.
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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.
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| 12.
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林田, 和宏 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />NO concentration measurement in the burnt gas from the catalytic combustion was carried out by using a laser-induced fluorescence method. A palladium catalyst supported on a cordierite honeycomb
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was used. The methance/air mixture, which was pre-heated to 530 K, was introduced into the catalyst honeycomb. To excite a NO molecule, an ArF excimer laser was used. Wavelength of the laser right was set at 193.375 nm. The laser sheet was introduced into the downstream of the honeycomb. In the case of a lean mixture, NO was observed after the honeycomb. On the other hand, in the case of a rich mixture, a blue flame at downstream from the honeycomb were observed, and NO was observed at the blue flame. In order to obtain the NO concentration from the NO fluorescence intensity, temperature dependency of the fluorescence intensity was investigated by using NO-N_2 mixture. Axial concentration distributions of NO were derived from the NO fluorescence intensity distributions. Furthermore, change of the NO emission level with equivalence ratio was investigated at the outlet of the honeycomb.
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| 13.
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HAYASHIDA, Kazuhiro ; SHIRAI, Hiroyuki ; AMAGAI, Kenji ; ARAI, Masataka
概要:
application/pdf<br />Journal Article<br />Rotational temperature of NO molecule in methane/air premixed flame was estima
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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.
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| 14.
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林田, 和宏 ; 白井, 紘行 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />Rotational temperature of NO molecule in methane/air premixed flame was estima
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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.
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| 15.
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秋山, 繁 ; 天田, 重庚 ; 千田, 哲也 ; 島田, 道男 ; 古谷, 典〓 ; 矢野, 不二夫
概要:
application/pdf<br />Journal Article<br />Nuclear power plants have the greatest potential for use in space ships, under
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water vehicles, and so on. Because the space and the weight for those plants have limitation, it is very important to develop new radiation shielding materials which have excellent mechanical strength and heat-resistant characteristics. Chromium carbide ceramics (Cr_3C_2) is the neutron absorber which is more excellent than titanium boride ceramics and has been investigated as a radiation shielding material. This report presents an evaluation of thermal shock strength by the laser irradiation technique for chromium carbide ceramics. Their temperature and thermal stress distributions are analyzed by the finite element method (FEM), and critical fracture curves, which can specify a critical power density for a given laser beam spot diameter, are obtained from the relationships between the spot diameter of the laser beam and the maximum tensile thermal stress. And furthermore, size effects to the fracture criterion of chromium carbide ceramics are examined, and the laser irradiation experiments are performed on chromium carbide ceramics using a CO_2 laser. Finally, theoretical results are compared with experimental ones, and the thermal shock strength P_L of Cr_3C_2 ceramics with laser irradiation is ～3.4 W/mm^2 for tension by the FEM analyses
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| 16.
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林田, 和宏 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />Laser induced fluorescence was applied for the measurement of OH concentration
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in the propane diffusion flames. A tunable, narrow band KrF excimer laser was used to excite the A(ν'=3)←X(ν""=0) band of OH radical. An emission spectrum of the induced light from the flames was measured by a spectroscope. An OH fluorescence component was picked up from the emission spectrum in order to obtain the accurate distribution of OH fluorescence in the flames. We call this method for spectrum-LIF (S-LIF). The spectrum of the induced light from the diffusion flames was compared with that of the premixed flames. Although the spectrum had only OH fluorescence components in the case of premixed flames, high intensity emission from the yellow flame appeared on the LlF image in the case of diffusion flames. To remove the high intensity emission from the LIF image, off resonance image was deducted from the OH resonance image as the background image. Using this deduction method, a planer laser induced fluorescence (P-LIF) was tried to measure the distribution of OH fluorescence. OH fluorescence distribution measured by P-LIF was compared with that of S-LIF. As the result, the P-LIF image qualitatively agreed with the data of S-LIF.
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| 17.
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新井, 雅隆 ; 天谷, 賢児 ; 長倉, 邦仁
概要:
application/pdf<br />Journal Article<br />Laser induced fluorescence method was applied for the measurement of NO concen
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tration in the propane and methane diffusion flames. A tunable, narrow band ArF excimer laser was used to excite the D (υ′=0) ←X (υ″=1) band of NO molecule. Emission spectrum of the induced light by a laser beam was measured by a spectroscope. Spectrum of the induced light from the diffusion flame was compared with that of the premixed flame. Although the spectrum had only NO fluorescence components on premixed flame, a lot of strong spectrum components related to the laser induced incandescence of the soot and laser induced breakdown appeared in the spectrum from the diffusion flame. NO fluorescence component was picked out from the emission spectrum with traversing the irradiate position of laser beam in order to obtain the accurate distribution of NO fluorescence on the flame axis. In this paper this method was named as S-LIF method. A planer laser induced fluorescence (P-LIF) method was tried to measure the distribution of NO fluorescence on the flame axis. In the P-LIF method, an interference filter was used to remove the obstructive light component from the LIF image. NO fluorescence distribution measured by P-LIF method was compared with that of S-LIF method. As the result, the P-LIF image qualitatively agreed with the data of S-LIF. It was confirmed that the interference filter did not remove completely the obstructive light components.
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| 18.
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秋山, 繁 ; 天田, 重庚 ; 島田, 道男 ; 千田, 哲也 ; 古谷, 典〓
概要:
application/pdf<br />Journal Article<br />Structural Ceramics have excellent wear- and heat-resistant characteristics. However, in some applications, they are exposed to very high temperatures and high heat-flux environments, and are
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also subjected to repeated thermal loadings that change rapidly with time. Such repeated thermal loadings are causes of material fracture. Therefore, it is important to investigate the thermal shock fatigue characteristics of these ceramics. We present results of thermal shock fatigue strength tests for a machinable structural ceramic called MACOR, composed of SiO_2-MgO-Al_2O_3. The thermal shock fatigue experiments were done using a CO_2 laser, and the crack generation of the specimens was measured from AE (acoustic emission) signals. Consequently, the thermal shock fatigue strength of MACOR was estimated from the critical power density, and it was proposed that the thermal shock strength of ceramics should be cstimated using a minimum value P_<LF> [W/mm^2] of the critical power density below which ceramic fracture is independent of the spot diameter. Finally, the P_<LF> of 0.2 W/mm^2 was obtained from thermal shock fatigue experiments using MACOR.
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| 19.
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天田, 重庚 ; 白井, 直樹
概要:
application/pdf<br />Journal Article<br />A thin plate is heated locally by a laser beam and simultaneously, a large thermal elastic plastic stress-strain state is generated in the heated, thin surface layer. This state can lead to
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plate bending upon cooling. The bending configuration depends mostly on the plate geometry, and heating and cooling process. We presents some experimental results of bending the plate in V-, U- and concave shapes. A model of this process is constructed and the theoretical predictions are carried out based on FEM analysis using eleastic-plastic theory. Bending angles obtained experimentally and theoretically are in good agreement.
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| 20.
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Akiyama, Shigeru ; Amada, Shigeyasu ; Yoshii, Tokuharu
概要:
application/pdf<br />Journal Article<br />Various structural ceramics have been developed as heat-resistant materials. In some applications it is anticipated that they will be exposed to very-high-temperature environments of the order of
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thousands of degrees. Moreover, these ceramics are subjected to thermal loadings which change rapidly with time. Therefore, it is very important to investigate their thermal shock characteristics. In this report, the distributions of temperatures and thermal stresses of cylindrical-shaped Al_2O_3 ceramics under irradiation by laser beams are analyzed using the finite element method. Critical fracture curves are obtained from the relationships between spot diameters of laser beams and maximum values of thermal stresses for various power densities of laser beams. The irradiation experiments yield these critical fracture curves, and theoretical and experimental curves are in good agreement.
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| 21.
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秋山, 繁 ; 天田, 重庚 ; 島田, 道男 ; 千田, 哲也 ; 吉井, 徳治
概要:
application/pdf<br />Journal Article<br />Nuclear power plants have the greatest potential for use in space ships, underwater vehicles, and so on. It is very important to develop new radiation shielding materials which have excellent
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mechanical strength and heat-resistant characteristics. Titanium boride ceramic (TiB_2) is an excellent neutron absorber and has been investigated as a radiation shielding material. This report presents an evaluation of thermal shock resistance by the laser irradiation technique for three kinds of titanium boride ceramics with 3, 8, and 15% porosity. Their temperature and thermal stress distributions are analyzed by the finite-element method, and the relationship between the spot diameter of the laser beam and the maximum tensile thermal stress is derived for various power densities of the laser beams. Critical fracture curves are obtained from these relationships, which can specify a critical power density for a given laser beam spot diameter. The irradiation experiments are performed on titanium boride ceramics using a C0_2 laser. Finally, theoretical results are compared with experimental ones.
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| 22.
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AKIYAMA, Shigeru ; AMADA, Shigeyasu
概要:
application/pdf<br />Journal Article<br />Structural ceramics are attracting attention in the development of space planes, aircraft and nuclear fusion reactors because they have excellent wear-resistant and heat-resistant
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characteristics. However, in some applications it is anticipated that they will be exposed to very-high-temperature environments of the order of thousands of degrees. Therefore, it is very important to investigate their thermal shock characteristics. In this report, the distributions of temperatures and thermal stresses of cylindrically shaped ceramics under irradiation by laser beams are discussed using the finite-element computer code (MARC) with arbitrary quadrilateral axisymmetric ring elements. The relationships between spot diameters of laser beams and maximum values of compressive thermal stresses are derived for various power densities. From these relationships, a critical fracture curve is obtained, and it is compared with the experimental results.
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| 23.
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秋山, 繁 ; 天田, 重庚 ; 島田, 道男 ; 吉井, 徳治
概要:
application/pdf<br />Journal Article<br />Various structural ceramics have been developed as heat-resistant materials. However, in some applications it is anticipated that they will be exposed to very-high-temperature environments of
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the order of thousands of degrees. Moreover, those ceramics are subjected to thermal loadings which change rapidly with time. Therefore, it is very important to investigate their thermal shock characteristics. In this report, the distributions of temperatures and thermal stresses of cylindrical-shaped Al_2O_3 ceramics under irradiation by laser beams are analyzed using the finite-element method. Critical fracture curves are obtained from the relationships between spot diameters of laser beams and maximum values of thermal stresses for various power densities of laser beams. The irradiation experiments lead to these critical fracture curves, and both theoretical and experimental curves are in good agreement.
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| 24.
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秋山, 繁 ; 天田, 重庚
概要:
application/pdf<br />Journal Article<br />Structural ceramics are attracting attention in the development of space ships, aircraft and nuclear fusion reactors because they have excellent wear-resistant and heat-resistant
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characteristics. However, in some applications it is anticipated that they will be exposed to very high temperatures of the order of thousands of degrees. Therefore, it is very important to investigate their thermal shock characteristics. In this report, the distributions of temperatures and thermal stresses of cylindrically shaped ceramics under laser beams are discussed using the finite element computer code (MARC) with arbitrary quadrilateral axisymmetric ring elements. The relationships between spot diameters of laser beams and maximum values of compressive thermal stresses are derived for various power densities. From these relationships, a critial fracture curve is obtained, and it is compared with the experimental result.
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| 25.
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長屋, 幸助 ; 武田, 定彦 ; 永井, 健一 ; 佐藤, 淳 ; 杉浦, 光則 ; 佐川, 竜一郎
概要:
application/pdf<br />Journal Article<br />This paper proposes a two-dimensional displacement sensor which is available to detect high speed phenomena such as high frequency vibrations. The sensor consists of a laser, polarisers, a beam
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splitter, solar cells and clean plates in which an index of double refraction varies in one direction. Since the clean plate as just mentioned has not been produced, this paper applies thin films sandwiched with a magnetic fluid, and the double refraction is generated by using permanent magnet. In this system, the laser beam propagating from the moving body is divided into two beams by a beam splitter, and the divided beams pass through the two clean plates whose refraction axes are in right angles with each other. An intensity of the laser beam after passing through the clean plate is detected by a solar cell. Then the position of each beam is decided by the intensity of the laser beam. Experimental tests have been performed to verify the principle as just mentioned.
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| 26.
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長屋, 幸助 ; 吉田, 彬 ; 井開, 重男 ; 山本, 哲也 ; 横山, 信行 ; 永井, 健一
概要:
application/pdf<br />Journal Article<br />This paper is concerned with a method for measuring masses of the magnetic particles in a fluid such as a magnetic fluid. Two methods are proposed, one of which is the phase difference procedure
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by use of a laser, and the other is the nuclear magnetic resonance (NMR) procedure. Experimental tests have been carried out to find masses of the magnetic particles in the magnetic fluid with various densities by using the methods mentioned above. It is clarified that the present methods are applicable to measure the masses in a fluid, including a few particles.
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| 27.
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小保方, 富夫 ; Bopp, Stefan ; Tropea, Cam
概要:
application/pdf<br />Journal Article<br />A simple adapter for a two-dimensional, backscatter, fiber-optic laser Droppler anemometer probe consisting of two glass plates has been developed to measure the spatial
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correlation of velocity fluctuations. A conventional two-color, four-beam LDA probe has been modified by reversing the placement of two of the fibers so that both the green and the blue control volumes measure the same velocity component. An adapter for beam separation is ten mounted behind the front lens to separate the two control volumes. In the present work, the measuring point separation was varied up to 3 mm in the lateral and vertical directions. By using only one glass plate 10 mm thick, it was also possible to achieve in-line (Axial) displacements of the control volumes of up to 3.5 mm. spatial correlations were performed in an intermittent jet flow in which the convective flow velocity could be deduced from the offset of the cross-correlation function.
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