Journal of Visualization - Volume 11, issue 1

Article Type: Other

Citation: Journal of Visualization, vol. 11, no. 1, pp. 1-1, 2008

Article Type: Other

Citation: Journal of Visualization, vol. 11, no. 1, pp. 3-8, 2008

Authors: Nakayama, Y.

Article Type: Research Article

Abstract: Visualization is an interdisciplinary imaging science devoted to making the invisible visible by means of the techniques of experimental visualization and computer-aided visualization. Since the first publication of Journal of Visualization (JOV) in 1998, the Journal has been providing state-of-the-art information on this imaging science in full color in order for better understanding of the phenomena. Since the first issue, 10 volumes, 40 copies and approximately 430 papers have been published. The Editorial Board is …composed of domestic and foreign researchers who are internationally active in this field. Thus, JOV is strongly characterized as an international technical journal. The JOV reached the 10th anniversary year in 2007, and the anniversary ceremonies were held in Tokyo, Hong Kong and Tallahassee. Show more

Keywords: Visualization, Journal of Visualization, Atlas of Visualization, Fantasy of Flow, Impact Factor

Citation: Journal of Visualization, vol. 11, no. 1, pp. 9-14, 2008

Authors: Kobayashi, T. | Tsubokura, M. | Oishi, M.

Article Type: Research Article

Abstract: Computer simulation and visualization techniques for automotive studies are reviewed through the history of computer-arded visualization techniques to celebrate the 10th anniversary of Journal of Visualization. Future direction of visualization study is also mentioned through the introduction of up-to-dated numerical visualizations.

Keywords: Visualization, Automobile, Computational Fluid Dynamics, Computer Aided Engineering

Citation: Journal of Visualization, vol. 11, no. 1, pp. 15-22, 2008

Authors: Kobayashi, T. | Tsubokura, M. | Oshima, N.

Article Type: Research Article

Abstract: The history of high-performance computing in turbulent flows is reviewed and their recent topics in industrial use are addressed. Special attention is paid to the validity of the method in flow visualization, and three-dimensional unsteady simulation is focused. Seemingly fundamental CFD technique for 3-D turbulence simulation has been well developed recently, but its practical use as an industrial tool has not yet become popular. An effort to close a wide gap between fundamental and practical use …of scientific computer simulation is introduced through the national project promoting computational science and its development in industries of the next generation. Show more

Keywords: HPC, LES, DNS, turbulence, CAE

Citation: Journal of Visualization, vol. 11, no. 1, pp. 23-32, 2008

Authors: Erkan, N. | Shinohara, K. | Okamoto, K. | Okamoto, T. | Fujii, T.

Article Type: Other

Citation: Journal of Visualization, vol. 11, no. 1, pp. 33-34, 2008

Authors: Jin, Z. | Someya, S. | Okamoto, K. | Hu, H.

Article Type: Other

Citation: Journal of Visualization, vol. 11, no. 1, pp. 35-36, 2008

Authors: Kim, S. H. | Chang, J. W. | Sohn, M. H.

Article Type: Research Article

Abstract: An unsteady flow visualization and force measurement were carried out in order to investigate the effects of the reduced frequency of a dragonfly-type model. The flow visualization of the wing wake region was conducted by using a smoke wire technique. An electronic device was mounted below the test section in order to find the exact position angle of the wing for the visualization. A load-cell was employed in measuring aerodynamic forces generated by a plunging motion …of the experimental model. To find the period of the flapping motion in real time, trigger signals were also collected by passing laser beam signals through the gear hole. Experimental conditions were as follows: the incidence angles of the fore-and hind wing were 0° and 10°, respectively, and the reduced frequencies were 0.150 and 0.225. The free-stream velocities of the flow visualization and force measurement were 1.0 and 1.6 m/sec, respectively, which correspond to Reynolds numbers of 3.4 × 10^3 and 2.9 × 10^3 . The variations of the flow patterns and phase-averaged lift and the thrust coefficients during one cycle of the wing motion were presented. Results showed that the reduced frequency was closely related to the flow pattern that determined flight efficiency, and the maximum lift coefficient and lift coefficient per unit of time increased with reduced frequency. Show more

Keywords: Dragonfly type Model, Flow visualization, Reduced frequency, Leading-edge vortex, Lift, Drag

Citation: Journal of Visualization, vol. 11, no. 1, pp. 37-44, 2008

Authors: Kim, J. S. | Sung, J. | Kim, S. | Kim, J. S.

Article Type: Research Article

Abstract: The three-dimensional vortical structures formed in the wake behind a road vehicle were measured using a particle image velocimetry (PIV) technique and the change of the structures by the existence of an air spoiler was investigated. The measurements were carried out in several x-y, y-z and z-x planes to obtain full three-dimensional flow fields, including an out-of-plane velocity component, obtained by interpolating the velocities in the other plane. Then, the velocity gradient tensor is evaluated to …obtain the vortex core by the λ_2 -definition. The relationship between streamwise, longitudinal and spanwise vortices is systematically analyzed by overlapping the vortex lines and vortex cores and the whole flow topology is compared in both cases with and without an air spoiler. As a result, an air spoiler was found to weaken the C-pillar vortices producing strong wing tip vortices, which reduce downwash flow and longitudinal vortices increase in the vertical direction. The recirculation zone formed when an air spoiler is installed is higher and narrower than without a spoiler. Show more

Keywords: particle image velocimetry (PIV), road vehicle, air spoiler, three-dimensional wake, vortex line, λ_2 method

Citation: Journal of Visualization, vol. 11, no. 1, pp. 45-54, 2008

Authors: Lee, C. H.

Article Type: Research Article

Abstract: In this study, spray tip penetration and dispersion in high-pressure environment were simulated experimentally with an emphasis on the swirl effect. A rotating constant volume chamber was designed in order to generate a swirl that could be varied continuously with a flow field that closely resembled the solid-body rotation. An emulsified fuel was injected into the chamber and the developing process of fuel spray was observed. The effect of swirl on the spray dispersion was analyzed …by measuring the dispersion area as a function of the spray tip penetration and the time after the start of the injection. The effect of swirl on the spray dispersion was quantified through getting a relationship between the swirl and the dispersion. The experimental results of the spray dispersion with time after the fuel injection process began showed similar characteristics to those of the spray tip penetration with time after the start of the fuel injection. The spray dispersion characteristics while varying the spray tip penetration were also investigated. The results showed that the spray dispersion depends linearly on the spray tip penetration, when it is small. As the spray tip penetrates into longer distance, the dispersion depends on the spray tip penetration to the power of 1.6. Show more

Keywords: Emulsion Injection Visualization, Spray Dispersion, Solid Body Rotating Swirl, Spray Tip Penetration, Diesel Engine, Fuel Injection

Citation: Journal of Visualization, vol. 11, no. 1, pp. 55-62, 2008