An experimental study on characteristics of cavitation and ballistic of axisymmetric slender body underwater movement

The Wind tunnel investigation of a slender body catamaran was conducted in order to determine its resistance characteristics, namely the effect of pressure and flow velocity changes for varied hull separation. The catamaran was tested in a wind tunnel belongs to Department of Mechanical Engineering, ITS, with hull separations of S/L = 0.2 to 0.4 and variation in Reynolds numbers up to 4.46 x 105. Pressure around the hull was measured using pressure tappings and the flow velocity behind the hull was also measured using a Pitôt-static tube. The experimental study shows that the pressure coefficient decreases when the hull separation declines and conversely, the flow velocity increases. The tests demonstrated a viscous interaction between the hulls, and form factors for the monohull and catamaran are derived. The demihull exhibited a form factor (1+k) of 1.265 and in the catamaran mode, the measured form factor (1+βk) was between 1.416 and 1.403. The results are in agreement with other published data.

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Experimental Study on Elastic Response of Circular Cross-section Slender Body to Forced Oscillation, Waves, and Current

Journal of Ocean Engineering and Technology ◽

10.5574/ksoe.2016.30.2.091 ◽

2016 ◽

Vol 30 (2) ◽

pp. 91-99

Author(s):

Ji-won Park ◽

Seung-Jae Lee ◽

Hyo-Jae Jo ◽

Jae-Hyuk Hwang ◽

Sung-Hoon Han

Keyword(s):

Experimental Study ◽

Cross Section ◽

Forced Oscillation ◽

Circular Cross Section ◽

Slender Body ◽

Elastic Response

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Preliminary Experimental Study on Aerodynamic Characteristics Control of Slender Body Using DBD Plasma Actuator

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES AEROSPACE TECHNOLOGY JAPAN ◽

10.2322/tastj.10.pe_97 ◽

2012 ◽

Vol 10 (ists28) ◽

pp. Pe_97-Pe_103

Author(s):

Hiroyuki NISHIDA ◽

Sakae MIZUKI ◽

Isao MIYAZAKI ◽

Satoshi NONAKA ◽

Taku NONOMURA ◽

...

Keyword(s):

Experimental Study ◽

Aerodynamic Characteristics ◽

Plasma Actuator ◽

Slender Body ◽

Dbd Plasma

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Experimental study on the restoration from a tilt-azimuth series for improvement in resolution

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010013955x ◽

1995 ◽

Vol 53 ◽

pp. 636-637

Author(s):

Norio Baba ◽

Norihiko Ichise ◽

Syunya Watanabe

Keyword(s):

Experimental Study ◽

Spherical Aberration ◽

Incident Beam ◽

Optical Parameters ◽

Beam Tilting ◽

Illumination Method ◽

Restoration Method ◽

Illumination Mode

The tilted beam illumination method is used to improve the resolution comparing with the axial illumination mode. Using this advantage, a restoration method of several tilted beam images covering the full azimuthal range was proposed by Saxton, and experimentally examined. To make this technique more reliable it seems that some practical problems still remain. In this report the restoration was attempted and the problems were considered. In our study, four problems were pointed out for the experiment of the restoration. (1) Accurate beam tilt adjustment to fit the incident beam to the coma-free axis for the symmetrical beam tilting over the full azimuthal range. (2) Accurate measurements of the optical parameters which are necessary to design the restoration filter. Even if the spherical aberration coefficient Cs is known with accuracy and the axial astigmatism is sufficiently compensated, at least the defocus value must be measured. (3) Accurate alignment of the tilt-azimuth series images.

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