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Volume 35, Issue 397
Displaying 1-7 of 7 articles from this issue
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Tadashi SHIOYA1987 Volume 35 Issue 397 Pages 63-68
Published: February 05, 1987
Released on J-STAGE: December 16, 2010
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Masami HAMANAKA1987 Volume 35 Issue 397 Pages 68-76
Published: February 05, 1987
Released on J-STAGE: December 16, 2010
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Mikio KAJITA1987 Volume 35 Issue 397 Pages 82-84
Published: February 05, 1987
Released on J-STAGE: December 16, 2010
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Masanori HAYASHI, Akira SAKURAI, Shigeru ASO1987 Volume 35 Issue 397 Pages 85-90
Published: February 05, 1987
Released on J-STAGE: December 16, 2010
JOURNAL FREE ACCESSA new type of thin film heat transfer gauge is applied to the measurements of heat-transfer coefficients in the interaction regions of oblique shock waves and fully developed turbulent boundary layers. It has been developed for the measurements of heat flux with high spatial resolution and fast response for wind tunnels with long flow duration. Experiments have been performed under the conditions of Mach number=4, total pressure=1.2MPa, Tw/T0=0.59-0.65, Reynolds number=1.3-1.5×107, and incident shock angles from 17.8 degrees to 22.8 degrees. Flow fields are visualized by the Schlieren technique. Both distributions of surface pressure and heat-transfer coefficient are measured throughout the interaction regions by scanning the shock generator parallel to the free stream. Owing to the high spatial resolution of the new sensor, complicated features of the aerodynamic heating in the interaction regions are revealed.View full abstractDownload PDF (4851K) -
Shigenori ANDO1987 Volume 35 Issue 397 Pages 91-101
Published: February 05, 1987
Released on J-STAGE: December 16, 2010
JOURNAL FREE ACCESSA concept of PAR (Power Augmented Ram Wing) is presented. It will be useful in future for over-water transport vehicles to carry passengers, cargos, and/or cars. It is much faster than ships, while it requires no run-way in contrast to airplanes. The PAR concept makes the fuselage-shape “aero-configured” rather than “hydro-configured”, and so decreases the parasite-drag singificantly. An empirical formula is found for the effective aspect ratio which is applicable to verious kinds of Ground Effect Wings. The present PAR concept has a variable geometry wing, in front of which tiltable turboprop engines are installed. Untill the take-off speed is exceeded, the wing is swept-forward with extended full span flaps (the outer ones are differential flaps). In cruising condition the wing becomes unswept. If the sea-state is bad the vehicle can fly off-ground effect with unswept wing. Thus cancelling operations is much more reduced than hovercrafts or hydrofoil-boats. Special devices are proposed for the tip-floats, which improve aero-dynamic efficiency and which alleviate load due to wave-impacts.View full abstractDownload PDF (14903K) -
Tomoari NAGASHIMA, Takeichiryo HIROSE1987 Volume 35 Issue 397 Pages 102-107
Published: February 05, 1987
Released on J-STAGE: December 16, 2010
JOURNAL FREE ACCESSTo clarify the effects of wake contraction, swirl velocity and mutual interactions on the cruising performances of a counter rotating propellers ATP, fundamental analyses based on the generalized momentum theory were carried out. Assuming a linear interaction scheme, the optimum propulsion efficiency and the wake geometry which minimize the total induced losses for a given thrust were established as solutions of a calculus of variations problem. The optimum combinations of operating parameters such as the thrust sharing ratio, the power sharing ratio and the disc area ratio between top and bottom propellers were also specified and their dependency upon the axial velocity, the total thrust level and the axial spacing were revealed. It was understood that, in addition to the counter rotating effect of propellers, upwash effect of the contracted top propeller wake on the outer part of the bottom propeller disc play a fundamental role for improving the propulsion efficiency of a CR ATP.View full abstractDownload PDF (347K) -
Shiki OKAMOTO1987 Volume 35 Issue 397 Pages 108-116
Published: February 05, 1987
Released on J-STAGE: December 16, 2010
JOURNAL FREE ACCESSThis paper describes an experimental study of the interference of two spheres placed on a plane boundary. The experiment was carried out in an N. P. L. type wind-tunnel having a working section of 500mm×500mm×2000mm in size at Reynolds number 4.74×104. The surface-pressure distributions of two spheres at various relative positions were measured and the drag, lift and side-force coefficients were determined from the surface-pressure distributions. The experimental results were compared with those of a single sphere.View full abstractDownload PDF (15036K)
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