※一部利用できない機能があります
| 1.
論文 |
論文
|
TAKEDA, Chikashi ; OHTA, Yuji ; ISHIMA, Tsuneaki ; ISHII, Kiyoshi ; OBOKATA, Tomio
概要:
application/pdf<br />Journal Article<br />In order to measure flow velocity in the swirl and radial directions of a cylinder of an engine in practical use by means of a laser Doppler anemometer(LDA)through a small measuring window on the
…
cylinder head, a back scattering fringe mode LDA is used. This LDA, however, can not be used to measure the velocity component in the axial direction of the cylinder. A single incidence-beam reference-mode LDA is developed to measure the velocity component along the optical axis of the LDA and is applied to measure the fluctuating flow velocity in the axial direction of the cylinder. Ensemble-averaged mean velocity and fluctuation intensity of the velocity as measured using the LDA show good agreement with those measured using the conventional fringe-mode LDA. Based on these results, it can be concluded that the reference-mode LDA is applicable to measurements of the flow velocity in the axial direction of the cylinder through the amall window on the cylinder head.
続きを見る
|
||
| 2.
論文 |
論文
|
武田, 親士 ; 太田, 祐司 ; 石間, 経章 ; 石井, 清 ; 小保方, 富夫
概要:
application/pdf<br />Journal Article<br />In order to measure flow velocity in the swirl and radial directions of a cylinder of an engine in practical use by means of a laser Doppler anemometer (LDA) through a small measuring window on
…
the cylinder head, a back-scattering fringe mode LDA is used. It, however, could not measure the velocity component in the axial direction of the cylinder. The single incidence-beam reference-mode LDA is developed to measure the velocity component along the optical axis of the LDA and applied to measure the fluctuating flow velocity in the axial direction of the cylinder. Ensemble-averaged mean velocity and fluctuation intensity of the velocity as measured by the LDA show good agreement with those measured by the conventional fringe-mode LDA. Based on these results, it can be concluded the reference-mode LDA is applicable to measurements of the flow velocity in the axial direction of the cylinder through the small window on the cylinder head.
続きを見る
|
||
| 3.
論文 |
論文
|
細谷, 肇 ; 小保方, 富夫
概要:
application/pdf<br />Journal Article<br />There have been many experiments to characterize Diesel fuel spray under steady-state conditions. However, the appropriate number of holes and the hole position on the sac to be used in the
…
experiment are not clear. To address this subject, we investigate Diesel type spray flows using a laser Doppler anemometer (LDA) and a phase Doppler anemometer (PDA). Spray flow characteristics such as mean and fluctuating two-component velocities, two-dimensional distribution of particle diameter and the variation of three parameters at the log-hyperbolic fitting for particle size distribution are given from measured data. Spray jets from four varieties of Diesel nozzle are compared with each other to clarity the differences in spray characteristics between them. The results show that the spray from the single-hole nozzle on top of the sac is distinct from the others.
続きを見る
|
||
| 4.
論文 |
論文
|
小保方, 富夫 ; 橋本, 徹 ; 五十木, 慎一 ; 柄沢, 隆夫 ; 志賀, 聖一 ; 倉林, 俊雄
概要:
application/pdf<br />Journal Article<br />The swirl and axial components of gas velocity in the disk-type combustion cha
…
mber of a firing engine were measured by an LDA. The engine was operated under the conditions of a speed of 1500rpm, η_υ=0.5, φ=1.4 and ignition timing of 30°BTDC. The gas velocities at 9 points on a diameter at midheight of the combustion chamber were analyzed by the cycle-resolved method. The bulk (mean) velocity was determined by the frequency discrimination method with the cut-off frequency of 667Hz. The flame propagation pattern was detected by ionization probes set at 17 points on the piston. It has been observed that, in the case of fired operation, the turbulence intensity is higher, the integral length and micro length scales are longer and the swirl flow is weaker and is eccentrically shifted compared with the case of motored operation. These results show that it should be noted that there are remarkable differences in the gas flow between motored operation and fired opeation.
続きを見る
|
||
| 5.
論文 |
論文
|
細谷, 肇 ; 小保方, 富夫
概要:
application/pdf<br />Journal Article<br />Diesel fuel spray from a single-hole-type injection nozzle is investigated under steady and atmospheric conditions in order to understand the unsteady Diesel spray. Axial and radial
…
velocity components of the spray at two constant injection pressures of 9.8MPa and 4.9MPa are measured by laser Doppler anemometer (LDA), and turbulence characteristics of the spray flow velocities are analyzed. Distributions of mean velocity and turbulence characteristics in the spray flow are compared with gas jets and other spray flows. It is found that the injected spray is accelerated in the region close to the nozzle exit, and this phenomenon may be estimated as a kind of cavitation caused by expansion of dissolved gas in the fuel. The decrease in centerline velocity along the nozzle axis is very small and the air entrainment factor is also shown to take a smaller value than in previous experiments.
続きを見る
|
||
| 6.
論文 |
論文
|
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
…
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.
続きを見る
|
||
| 7.
論文 |
論文
|
小保方, 富夫 ; 松尾, 典孝 ; 平野, 嘉男
概要:
application/pdf<br />Journal Article<br />ピストン・リード弁付きクランク室圧縮形二サイクル機関の流れをレーザ流速計で実時間測定した.その結果,交換窓や回転窓の使用が不可欠であることがわかった.また,
…
実機の吸気流および排気流は駆動と発火時によりかなり異なったパターンを示すが,掃気流ではあまり差異はない.さらに機関を一連の管系におきかえ,特性曲線法を用いたシミュレーションで求めた駆動と発火時の各管内流は実測値とよく一致した.
続きを見る
|
