All issues
Volume 20, Issue 78
Displaying 1-10 of 10 articles from this issue
- |<
- <
- 1
- >
- >|
-
Yuichi MATSUO, Kazuyo SUEMATSU2000 Volume 20 Issue 78 Pages 197-202_1
Published: July 01, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (11581K) -
Chisachi KATO2000 Volume 20 Issue 78 Pages 203-208_1
Published: July 01, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (8467K) -
Hideo MIYACHI, Yoshihito KIKKAWA2000 Volume 20 Issue 78 Pages 209-214_1
Published: July 01, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (10714K) -
Shigeki MAEDA, Yoshiyuki SAWA, Yasuhiko FUJIKAWA2000 Volume 20 Issue 78 Pages 215-220_1
Published: July 01, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (9478K) -
Kazuhiro KOZUKA, Toshihiro OZASA, Kiyomi KAWAMURA2000 Volume 20 Issue 78 Pages 221-227_1
Published: July 01, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSA single cylinder visualization engine with the TCC (transparent collimating cylinder) was applied to the study of a direct-injection gasoline engine. Fuel sprays, mixture forma-tion and combustion process in the cylinder were observed using the schlieren method. The schlieren images were analyzed by image analysis technique. The shapes of the fuel spray are drastically changed with the injection timing ; namely oval shaped when in-jecting during the suction stroke, conical shaped when injecting near BDC, and bell shaped when injecting during the compression stroke. The fuel/air mixture formations also change with the injection timing. When the injection timing is late, the mixing of fuel and air is also late and the luminous region in the schlieren image of the mixture be-comes clear. In the case of the injection timing of 60 deg. before TDC, the injected fuel spray impinges on the top of the piston and the fuel/air mixture exists around the top of the piston, so that miss fire and abnormal combustion occur.View full abstractDownload PDF (6791K) -
"(3rd Report, Effects of Jet-Exit Conditions on Vortex Formations)"Toshihiko IKEDA, Kiyozumi FUKAMI, Masashi ARAKI, Takashi YOSHIDA, Tada ...2000 Volume 20 Issue 78 Pages 228-234
Published: July 01, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSThe purpose of this experiment is to make clear the effect of jet-exit conditions on the vortex formations of pulsating jets. Three exit conditions, two kinds of nozzles and an orifice are used in the experiment. One of these nozzles has a long parallel section, and the other has a short one. The pulsating jets are generated by Scotch yoke mechanism. The flow is visualized by a hydrogen bubble method. Obtained results are as follows: The flow patterns are strongly affected by jet-exit conditions. For the nozzle jets, the fre-quency of vortex formation agrees with that of the jet pulsation. For the orifice jet, a large scale vortex caused by the pulsation and a lot of vortices due to the shear layer in-stability are formed, and the vortices coalesce. The vortices of the orifice jet move down-stream faster than those of the nozzle jets.View full abstractDownload PDF (4353K) -
Hiroyuki SUGAWARA, Sadao MORI, Shinichi YODA, Ryouji IMAI, Makoto OHTS ...2000 Volume 20 Issue 78 Pages 235-242
Published: July 01, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSWe developed a technique for measuring instantaneous, three-dimensional velocity components in liquid flows by using a digital image processing system, and here we describe a particle tracking velocimery technique improving the tracking of the initial and terminal positions of tracer particles. By using color cameras and a RGB flashlight source three images of the tracer particles are obtained: one at their initial positions; their ter-minal positions, and along their pathline. The images of the initial and the terminal posi-tions are paired by using the pathline image, and the velocity vectors are calculated. We studied image processing algorithms for obtaining three-dimensional-flow vectors from the images produced by the two cameras and for distinguishing duplicate images of the tracer particles. We confirmed this technique is useful for three-dimensional flow observa-tion.View full abstractDownload PDF (3742K) -
Masanori NAKAI, Masamitsu ARITA, Jun UMEMOTO2000 Volume 20 Issue 78 Pages 243-249
Published: July 01, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSThe flow and spreading mechanism of three-dimensional negatively buoyant surface jets discharged on a sloping bottom was experimentally investigated by flow visualization and exhaustive temperature measurement. The flow gradually varies, through its running process, from a jet-like characteristic to a buoyancy-dominating characteristic which has great lateral spreading in surface and bottom layers and apparent constriction in a middle layer. Streamwise variations of spreading widths in upper and lower layers were made clear as a function of initial densimetric Froude number Fo, and their features were discussed associated with the flow characteristics. In addition, a hypothesis on the flow and spreading mechanism in the buoyancy-dominating region could be presented through physical consideration.View full abstractDownload PDF (4684K) -
Koichi ICHIMIYA, Yoshio YAMADA2000 Volume 20 Issue 78 Pages 250-255
Published: July 01, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSThis paper describes the heat transfer characteristics and visualization on a single cir-cular laminar impinging jet in comparatively narrow space with confined wall. Tempera-ture distribution and velocity vectors in the space were obtained numerically by solving three-dimensional governing equations for the Reynolds number Re=400-2000 and the dimensionless space H=0.25-1.0. Forced convection region, mixed convection region and natural convection region exist along the radial direction. Local heat flux was visualized by using thermosensitive liquid crystal. The position and the size of recirculation flow on the impingement surface moves to downstream and increases with increase of Re and L, respectively. Average Nusselt number Num was evaluated as functions of Re and L.View full abstractDownload PDF (12973K) -
Takahide TABATA, Tsutomu NOZAKI, Hui LI2000 Volume 20 Issue 78 Pages 256-262
Published: July 01, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSFlow visualization using Laser Light Sheet method was carried out to observe the large scale eddies in bounded jet. In order to reveal flow structure of a turbulent bounded jet in terms of period and time delay, the wavelet cross-correlation analysis was employed to analyze cross-correlation relationships between X-components of the fluctu-ating velocities at two different points near the wall in the near field. From the distribu-tions of the wavelet cross-correlation coefficients, similar structures of eddy motions with various scales were shown and branching of eddy structures was observed. The periodic eddy motions can be easily determined in terms of period and delay time. The large scale structure in bounded jet has been confirmed, comparing the information from flow visualization with the result of analysis.View full abstractDownload PDF (11436K)
- |<
- <
- 1
- >
- >|