※一部利用できない機能があります
| 1.
論文 |
論文
|
長谷川, 和之 ; 茂木, 俊夫 ; 天谷, 賢児 ; 新井, 雅隆
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
|
||
| 2.
論文 |
論文
|
佐藤, 博之 ; 天谷, 賢児 ; 新井, 雅隆
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
|
||
| 3.
論文 |
論文
|
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
…
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.
続きを見る
|
||
| 4.
論文 |
論文
|
斉藤, 正浩 ; 荻原, 五郎 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />Behavior of spray-to spray impingement, where two spray jets were formed EFI (Electronic Fuel Injection) nozzles and impinged each other, was studied experimentally. This system was
…
named MISS EFI. Spray penetration and the Sauter mean diameter of the spray were measured to investigate the effect of spray-to-spray impingement. When the impingement location was set at the vicinity of the nozzles, impingement phenomena became to be jet to jet impingement of the liquid column. In this condition, the penetration became shorter than that of the individual penetration. However, the penetration did not changed after spray-to-spray impingement. From the photographs of jet-to-jet impingement, it was confirmed that the liquid film was formed by the impingement, and then this liquid film disintegrated to small droplets. In the spray-to-spray impingement, on the other hand, the relatively large droplets still existed in the impinged spray, because the two sprays crossed each other without disintegration of the droplets. The photograph of the spray-to-spray impingement showed that the droplet-to-droplet impingement in the spray was rarely observed. Further, the chance of coagulation of the droplets was less observed than the disintegration of the dropled. These behavior of the spray-to-spray impingement agreed with the reduction of the Sauter mean diameter of the impinged spray.
続きを見る
|
||
| 5.
論文 |
論文
|
伊東, 明俊 ; 天谷, 賢児 ; 新井, 雅隆 ; 三舩, 博史
概要:
application/pdf<br />Journal Article<br />This paper experimentally investigates a behavior of a bioconvective pattern under super gravitational fields. Experimental materials are the high density culture media of Tetrahymena. A
…
centrifugal force was used to synthesize various super gravity conditions by using a spin tester that can generate 1-12[G]. To realize the decreasing effect of bioconvection pattern size by the increase of synthesized gravity, different lengths of a rotative beam are used to change the rate of Corioli's force and synthesized gravity. The main results are as follows: (1) The size of the convection pattern is reduced by an increase of the synthesized gravity. (2) Under synthesized gravitational field, the stream mode of bioconvection is changed by the Corioli's force. (3) The maximum transition velocity (upward, downward) of Tetrahymana is obtaind with the 2-4[G] condition. (4) The decrease in the size of convection pattern is due to the composite gravity.
続きを見る
|
||
| 6.
論文 |
論文
|
岡本, 雄一郎 ; 荻原, 五郎 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />A six-stroke diesel engine which was proposed by authors had second compression and second combustion strokes which were added on a four-stroke diesel engine. Numerical prediction and experiments
…
on six-stroke engine which were carried out previously, showed that a six-stroke diesel engine could reduce NO concentration and shorter ignition delay could be attained in second combustion. Using various fuels on second combustion, it might be possible to improve more the emission characteristics. In this report, Methanol was used in the second combustion to improve the six-stroke engine performance. As the result, NO concentration in the exhaust gas decreased with delaying of the injection timing at second combustion and increased with an increase of the heat allocation ratio of second combustion stroke when the injection timing at first combustion stroke was fixed. Smoke wasn't exhausted at all when Methanol was put into the second combustion stroke. NO concentrations were affected by the heat allocation ratio and related with gas temperature. It was confirmed that the NO concentration of the Diesel fuel-Methanol engine become lower compared with that of the Diesel fuel engine.
続きを見る
|
||
| 7.
論文 |
論文
|
岡本, 雄一郎 ; 荻原, 五郎 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />A Six-stroke diesel engine was developed and its performance was evaluated. This engine had second compression and second combustion strokes which were added on the four stroke diesel engine.
…
To control the fuel injection ratio and injection timings for first and second combustion strokes independently, two fuel pumps were attached to the engine. Effect of the fuel allocation ratio between first and second combustion strokes on the engine performance was investigated. Engine performance of the six stroke diesel engine was compared with that of the four stroke diesel engine which was the base engine of the six stroke engine. As a result, NO concentration in the exhaust gas decreased with a delaying of injection timing at second combustion stroke, but the injection timing at first combustion stroke didn't influence NO concentration. NO concentration decreased with an increase of allocation fuel ratio into the second combustion stroke. A trade-off relation between NO and soot concentration was observed against the change of allocation ratio. From the comparison between six and four stroke engine, it was confirmed that the NO concentration of the six stroke engine becomes lower than that of the four stroke engine.
続きを見る
|
||
| 8.
論文 |
論文
|
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
…
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.
続きを見る
|
||
| 9.
論文 |
論文
|
江原, 拓未 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />In this paper, behaviors of diesel spray injected along a wall were experimentally investigated. In order to clarify the wall effect on spray structure, the geometry of the wall and its
…
relative position to the spray axis were varied. Structures of spray injected into a high-pressure atmosphere were recorded by high-speed photographs. Results shows that the asymmetrically large vortexes in the spray were induced by the wall effect, and the spray penetrating along the wall was deviated to the wall surface. This phenomenon is called the Coanda effect in the field of fluid dynamics. The growth orientation of spray was defined by image analysis. Maldistribution ratio of spray area was defined for the quantitative estimation of the spray deviation behavior. The spray deviating conditions such as the geometry of the wall and its relative position to the spray axis were fined.
続きを見る
|
||
| 10.
論文 |
論文
|
天谷, 賢児 ; 張, 峰 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />The performance of a six stroke diesel engine which has been proposed by the authors was experimentally investigated using a cyclical rapid-compression-expansion machine. The ignition delay and the
…
maximum heat release rate in the first and second combustion processes were measured under the various conditions of wall temperature of the engine cylinder. An optical fiber probe connected to a photo sensor was installed into a combustion chamber to measure the ignition delay and to obtain the luminosity of soot exidation in the second compression process. The experimental data were compared with the numerical predictions from the 1st report. As a result, the soot oxidation phenomenon in the second compression process was numerically and experimentally confirmed. It was clarified that the experimental data of the wall temperature effect on ignition delay qualitatively agreed with the numerical prediction.
続きを見る
|
||
| 11.
論文 |
論文
|
新井, 雅隆 ; 井田, 祐一 ; 天谷, 賢児
概要:
application/pdf<br />Journal Article<br />The performance of a six-stroke diesel engine which has been proposed by the authers was numerically predicted using a phenomenological model developed in the previous study. Concentrations of nitric
…
oxide and soot are calculated from the simple phenomeno
続きを見る
|
||
| 12.
論文 |
論文
|
新井, 雅隆 ; 天谷, 賢児
概要:
application/pdf<br />Journal Article<br />Droplet evaporation on a hot surface under super-gravitational fields was experimentally inves tigated. A test chamber attached to the end of a rotating arm was constructed to produce the
…
quasi-super-gravitational fields. A hot surface, droplet-forming equipment and a video camera for measuring the lifetime of a droplet were installed in a test chamber. Lifetime curves of water, n-decane and benzene were measured under the gravity of G = 1 to 12. As a result, it was found that an increase of the gravitational acceleration led to the decrease of lifetime near the Leidenfrost point.
続きを見る
|
||
| 13.
論文 |
論文
|
新井, 雅隆 ; 井田, 祐一 ; 天谷, 賢児
概要:
application/pdf<br />Journal Article<br />The performance of a 6-stroke diesel engine was numerically analyzed by means of a simple thermodynamical model. Since the 6-stroke diesel engine proposed in this report has two combustion
…
processes in one cycle, it will offer new methods of the Combustion Control which could not be attained in an ordinary 4-stroke diesel engine. For example, the second combustion stroke provides the oxidation process of the soot that formed in the first combustion stroke. With this method, the in-cylinder gas temperature related to the NO_x and soot formation in the combustion processes was predicted. It was confirmed that under various conditions, the maximum gas temperature of the 6-stroke diesel engine was lower than that of the 4-stroke engine. Furthermore, a 6-stroke low-heat-rejection diesel engine was analyzed. It was predicted that in comparison with the temperature in an ordinary 4-stroke engine, a higher thermal efficiency would be attained with a lower in-cylinder gas temperature.
続きを見る
|
