※一部利用できない機能があります
| 1.
論文 |
論文
|
川口, 知宏 ; 長瀧, 翼 ; 天谷, 賢児 ; 古畑, 朋彦 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />Ignition and combustion characteristics of diesel spray impinging on a wall were experimentally investigated. Ignition position and appearance position of the luminous flame
…
kernel were stereoscopically observed using a two-way fiber optical system. Flat
続きを見る
|
||
| 2.
論文 |
論文
|
新井, 雅隆 ; 天谷, 賢児 ; 長瀧, 翼 ; 沖田, 秀樹
概要:
application/pdf<br />Journal Article<br />Ignition and combustion characteristics of diesel spray impinging on an inclined wall were experimentally investigated. Ignition position and appearance position of the
…
luminous flame kernel were stereoscopically observed using a two-way fiber optical system. Flat impingement wall was fixed in a high temperature, high pressure combustion chamber. Inclined angle of the flat wall was set at 30 degees or right angle against the center axis of the injection spray. Distance from nozzle tip to the impingement point on the wall was set at 50mm. Effect of ambient temperature on ignition position was investigated. As the result, ignition positions were observed near the spray periphery in the both cases of 30 degrees and right angle impingements. However, the luminous flame appeared near the wall surface at downword side of inclined wall because the fuel rich region was formed around the downword side of spray impingement point.
続きを見る
|
||
| 3.
論文 |
論文
|
河野, 雅文 ; 天谷, 賢児 ; 新井, 雅隆
概要:
application/pdf<br />Journal Article<br />Effect of cetane number on ignition delay and ignition location of disesel spray was experimentally investigated. Five kinds of fuels, which had different cetane numbers of light fraction and
…
heavy fraction of fuel, were used. As a result, the ignition delay was not so affected by the change of cetane number, however, the ignition location was strongly affected by a cetane number. When the light fraction cetane number was low, the ignition was not observed near the nozzle. And when the heavy fraction cetane number was high, the ignition was observed at the position far from the nozzle. Ignition position had an effect on flame development. When the ignition occurred near the nozzle, flame development rate was slow. When the ignition occurred at the position far from the nozzle, flame development rate was fast. In case of the ignition position was far from the nozzle, effect of the cetane number on flame development was remarkable.
続きを見る
|
||
| 4.
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
|
||
| 5.
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
|
||
| 6.
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
|
||
| 7.
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
|
||
| 8.
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
|
||
| 9.
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
|
