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Akira NAGASHIMA
1985 Volume 51 Issue 467 Pages
2029-2035
Published: July 25, 1985
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Yoichiro MATSUMOTO
1985 Volume 51 Issue 467 Pages
2036-2042
Published: July 25, 1985
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Shigeru OSHIMA, Tsuneo ICHIKAWA
1985 Volume 51 Issue 467 Pages
2043-2052
Published: July 25, 1985
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Hiromu SUGIYAMA, Nobuhiro HARIU, Masato SEKIYAMA, Kazuhiko SATO, Kyouk ...
1985 Volume 51 Issue 467 Pages
2053-2060
Published: July 25, 1985
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Tamotsu IGARASHI
1985 Volume 51 Issue 467 Pages
2061-2067
Published: July 25, 1985
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Hitoshi MURAI, Shigenao MARUYAMA
1985 Volume 51 Issue 467 Pages
2068-2075
Published: July 25, 1985
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Junichi KUROKAWA, Masahiro MORIKAWA
1985 Volume 51 Issue 467 Pages
2076-2083
Published: July 25, 1985
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Kazuo MATSUUCHI, Tsutomu ADACHI
1985 Volume 51 Issue 467 Pages
2084-2090
Published: July 25, 1985
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Yoshiro KAGEYAMA, Hideo OSAKA, Hidemi YAMADA, Shigeru HASEGAWA
1985 Volume 51 Issue 467 Pages
2091-2097
Published: July 25, 1985
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Masaru MORIYA, Hiroshi SAKAMOTO
1985 Volume 51 Issue 467 Pages
2098-2104
Published: July 25, 1985
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Takao INAMURA, Nobuki NAGAI, Kazutoshi MORI, Masahiro KIMURA, Keiji KA ...
1985 Volume 51 Issue 467 Pages
2105-2113
Published: July 25, 1985
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Hideo YANADA, Akira HIBI, Tsuneo ICHIKAWA
1985 Volume 51 Issue 467 Pages
2114-2122
Published: July 25, 1985
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Akira HIBI, Satoshi KUMAGAI
1985 Volume 51 Issue 467 Pages
2123-2131
Published: July 25, 1985
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Masataka SATO
1985 Volume 51 Issue 467 Pages
2132-2139
Published: July 25, 1985
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Kunio HIJIKATA, Yasuo MORI, Paotai Wei
1985 Volume 51 Issue 467 Pages
2140-2147
Published: July 25, 1985
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Akio SAITO, Shin-ichiro NAGAKUBO, Yoshio UTAKA, Kozo KATAYAMA
1985 Volume 51 Issue 467 Pages
2148-2157
Published: July 25, 1985
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Eiji HASAGAWA, Fumio NAGASHIMA
1985 Volume 51 Issue 467 Pages
2158-2165
Published: July 25, 1985
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Sadayuki TANAKA, Takeshi KUNITOMO, Toshimi YOSHIDA
1985 Volume 51 Issue 467 Pages
2166-2175
Published: July 25, 1985
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Koichi HISHIDA, Hisaichi WANAJO, Masanobu MAEDA
1985 Volume 51 Issue 467 Pages
2176-2183
Published: July 25, 1985
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Yasutaka NAGANO, Yuan SUN, Mikio HISHIDA
1985 Volume 51 Issue 467 Pages
2184-2192
Published: July 25, 1985
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Hiromu BABA, Kimio KANEYAMA
1985 Volume 51 Issue 467 Pages
2193-2201
Published: July 25, 1985
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Hiroshi HAYASAKA, Kazuhiko KUDO, Hiroshi TANIGUCHI
1985 Volume 51 Issue 467 Pages
2202-2210
Published: July 25, 1985
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Akira UMEMURA, Minoru MARUO
1985 Volume 51 Issue 467 Pages
2211-2217
Published: July 25, 1985
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Katsuyuki KONISHI, Michikata KONO, Kazuo IINUMA
1985 Volume 51 Issue 467 Pages
2218-2224
Published: July 25, 1985
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Yozo TOSA, Kunihiko SHIMODA, Keizo GOTO, Tsuneo HARADA, Satsuo FUJI
1985 Volume 51 Issue 467 Pages
2225-2234
Published: July 25, 1985
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Hideaki TANABE, Tomohide SORIHASHI, Seiichiro KARITA, Jong-Yol HA, Haj ...
1985 Volume 51 Issue 467 Pages
2235-2242
Published: July 25, 1985
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Hidenori TASAKA, Hiroyuki YAMAMOTO, Shin MATSUOKA
1985 Volume 51 Issue 467 Pages
2243-2248
Published: July 25, 1985
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Shigeru OSHIMA, Tsuneo ICHIKAWA
1985 Volume 51 Issue 467 Pages
2249-2257
Published: July 25, 1985
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The influence of cavitation on the thrust characteristics of the oil hydraulic poppet valve was studied experimentally. The state of cavitation occurring was observed carefully and the pressure distributions along the surface of the poppet cone and the valve seat were measured in detail using the half cut model. The comparison of the three kinds of thrust coefficients, obtained by integrating of the pressure distribution on the poppet surface, applying the momentum theory and measuring directly the thrust force with the full shaped model, was made. As the result, the effects of cavitation on the thrust force characteristics and the mechanism of them were made clear. It was also found that especially in case of converging flow valve, the pressure distribution arround the downstream jet was complicated and had large effects on the thrust force characteristics.
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Osamu MOCHIZUKI, Hideo YAMADA, Haruo YAMABE
1985 Volume 51 Issue 467 Pages
2258-2264
Published: July 25, 1985
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A flow around a wedge in a planar jet, influenced by a edge tone, was investigated primarily by relating smoke visualized vortices to velocity and sound pressure signals. Following main results were found. (1) Two rows of vortices due to the instability of free shear layers of the jet were arranged alternately; they were split by the wedge, and then each vortex performed pairing motion with vortex shed from the corners of the wedge. (2) The frequency of sinusoidal wave observed near the outlet of the jet agreed with that of the edge tone. (3) The vortex coalescence was definitely related to the edge tone.
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Seiichi TANIGUTHI, Katsumi MIYAKOSHI, Seiji DOHDA
1985 Volume 51 Issue 467 Pages
2265-2271
Published: July 25, 1985
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The characteristics of the fluid forces acting on a square cylinder and flow patterns around the cylinder experimentally investigated when the cylinder was placed near and in a free turbulent mixing layer. The flow patterns near the under side of the cylinder, which faces to the high velocity side of the mixing layer, were found to be divided into the perfect separated flow (η< - 0.05) and the reattachment flow (η> - 0.05) . At this boundary η
M≅, the time-mean lift force attained its minimum value. It became also clear that the fluctuating fluid forces were very small over η
M and their distributions with respect to η had similarities when h / δ≲ 0.617, h being the side length of the cylinder and δ the width of mixing layer.
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Nobuhide KASAGI, Masaru HIRATA, Kouichi NISHINO
1985 Volume 51 Issue 467 Pages
2272-2280
Published: July 25, 1985
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Coherant fluid motions near the wall in a fully-developed two-dimensional turbulent channel flow have been visualized by using a sophisticated hydrogen-bubble techique with partially insulatied fine tungsten wires, which generate segmental hydrogen-bubbles, at several distances from the wall. These flow visualizations supply not only a direct evidence for the existence of streamwise vortical motions but quantitative data of fluid motions in the wall region. Further data reduction produces instantaneous distributions of two velocity components of v and w as well as streamwise vorticity of ω
x in the y - z plane perpendicular to the flow direction. The instantaneous contours of streamwise vorticity thus obtained show pseudo-periodicity in the spanwise direction and also double-layer structure in the direction normal to the wall. The compatibility of the pseudo-vortical structure with what is known about the near-wall turbulence is tested and confirmed by a simple structural model based upon unsteady spanwise-periodic secondary motions.
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Shigetaka FUJITA, Hideo OSAKA, Goro UENO
1985 Volume 51 Issue 467 Pages
2281-2287
Published: July 25, 1985
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Detailed measurements of turbulence quantities in the three-dimensional jet issuing form the cruciform nozzle have been made in oreder to investigate the similarity of each turbulent profile and the streamwise development of the characteristic scales. Experimental results are summarized as follows : For the far downstream extent, the decay rate of turbulent velocity scale is slower than that of mean velocity scale, and the pertinent properties such as three-components of turbulent intensity and Reynolds shear stress are similar in the extent of x / d ≥100. The Reynolds number based on the velocity scale U
0x and the length scale b' is constant, so the present turbulent jet steadily remains.
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Yoshikazu SUEMATSU, Tadaya ITO, Toshiyuki HAYASE, Norihiko KATO
1985 Volume 51 Issue 467 Pages
2288-2296
Published: July 25, 1985
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This paper treats the vortex breakdown of the axisymmetric type in a swirling pipe flow, in reder to clarify the growing process of the bubble. The unsteady flow field is investigated based on the inviscid linear theory of the internal wave (inertia wave). The expression of the time dependent flow field with the internal wave propagation whibh satisfies the condition of arbitrary velocity change at the upstream boundary of the circular pipe, is derived. Using this expression, the transition of the flow field, the streamlines and the streaklines calculated by computer, are examined. The unsteady flow field, as the result of a sudden azimuthal velocity change at the upstream boundary, clearly shows the birth of the bubble and the growing process into a stationary state. The theoretical results are compared with the experimental growing process of the bubble in an actual swirling pipe flow obtained by the visualization technique. Both results agree with each other fairly well concerning the bubble structure during the growing period. The behaviour of the flulid elements which are entrained into the bubble is also mentioned from the results of calculated pathlines.
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Seiichi WASHIO, Tadataka KONISHI, Takashi OKAMURA, Shigeaki KAKUTANI, ...
1985 Volume 51 Issue 467 Pages
2297-2303
Published: July 25, 1985
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The present paper deals with an experimental review of orifice flows in oil hydreulic lines. Pressure differences were measured between two separated points on a tube wall downstream of an orifice. Unexpectedly an abrupt vanishment of pressure recovery was observed under a specified rate of flow. Measurement of continuous pressure recovery profiles revealed that this 'vanishment' resulted from an unknown phenomenon which characterizes orifice flows of low Reynolds number; the pressure recovery region starts to remove downstream when Reynolds number falls below a critical value, and it drifts away farther from the orifice as Reynolds number decreases. The critical Reynolds number becomes smaller for a greater enlargement ratio of an orifice. Perplexingly it also varies with the line pressure.
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Eiji HASEGAWA, Shuichiro YAMASHITA
1985 Volume 51 Issue 467 Pages
2304-2312
Published: July 25, 1985
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Nonlinear waves on a thin elastic plate horizontally separating an upper flulid stream and a lower one are analysed theoretically. The lower stream is denser. The elastic plate is governed by the equation for large deflections including the in-plane forces due to the longitudinal deformations of the plate. Two fluid streams are assumed to be incompressible and inviscid, but on the elastic plate the balance of the normal component of force is expressed by taking the viscous stress into account. Some progressive waves of finite amplitude are found on the elastic thin plate. The nonlinear elevation of the elastic plate is obtained keeping up to the third order approximation in the wave amplitude. The unsteady amplitude of waves tend to a finite limit after a long time under the action of the viscosity of the fluid.
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Takahiko TANAHASHI, Tatsuo SAWADA, Kazuyuki SHIZAWA, Tsuneyo ANDO
1985 Volume 51 Issue 467 Pages
2313-2320
Published: July 25, 1985
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Although much progress has already been made in solving problems in step responses of pressure in a linear taperd pipe, new developments are still needed before the two dimennsional wave equation can be solved routinely. This paper describes one such development. A new method of solving one dimensional wave equatin in linear tapered copound pipes with arbitrary cross-sections has been devised. Results which are obtained from this theory are compared with experiments in pipes with square cross-sections. And we obtained the following conclusions: (1) Damping coefficients in an arbitrary cross-section are defined and are expressed analytically for some representative cross-sections. (2) The viscous solution of wave equatin obtained by Laplace transformation explains well distorted pressure histories in a linear taperd pipe with an arbitrary cross-section. (3) Pressure waves in a square cross-section include higher modes of frequensy and damp rapidly more than ones in a circular cross-section. But fundamental characteristics as waves are independent of the cross-section of the pipe except for the small aspect ratio.
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Yoshinobu MORIKAWA, Yutaka TSUJI, Toshitsugu TANAKA
1985 Volume 51 Issue 467 Pages
2321-2329
Published: July 25, 1985
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An optical fiber probe was developed for measurements of velocities and concentrations of solid particles. This probe was applied to an air-solid two-phase flow in a horizontal pipe, and distributions of velocities and concentrations were obtained over the pipe cross section. It was found that the distribution of the particle concentratin is exponential in the vertical direction. Particle velocities show unsymmetrical distributions which correspond to the concentrations. These unsymmetrical flow structures became more remarkable at low air velocities and high loading ratios. As a result of data arrangements the gradient of concentration is found to be well correlated to the particle to air velocity ratio.
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Kohichi HISHIDA, Kazuhiro KANEKO, Masanobu MAEDA
1985 Volume 51 Issue 467 Pages
2330-2337
Published: July 25, 1985
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Turbulence structures of downward blowing circular jet inbvolving fine glass particles have been investigated to clarify the basic phenomena of turbulence motion in two-phase suspension flow. The three-beam laser Doppler anemometry, which had an appropriate signal processing system for the measurments of velocities with particle size discrimination, has been employed for simultaneous measurements of two component velocities of gas and particle phases. The velocity fluctuations in two-phase system was larger in the main flow direction than the direction normal to the main flow, while Reynold shear stresses of gas phase decreased in the whole region. This phenomenon of reduction of turbulence motion could be related to the correlation of fluctuation of two-component velocities of each phase.
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Yuzuru EGUCHI, Genki YAGAWA
1985 Volume 51 Issue 467 Pages
2338-2344
Published: July 25, 1985
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The natural boundary conditioin of traction has been used in a penalty finite element method. Since a variable of pressure does not explisitly appear in this method, the essential boundary condition of pressure can not be introduced. It is, however, convenient to give pressure values on boundaries for some problems. This paper presents a new formulation in which pressure can be prescribed through the natural boundary condition. The solutions from the present method and the former one are compared with each other numerically and the defference is descussed.
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Takeo KAJISHIMA, Susumu MURATA, Yutaka MIYAKE
1985 Volume 51 Issue 467 Pages
2345-2350
Published: July 25, 1985
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The problem of the steady laminer flow past an arbitrary body is formulated using the boundary element method. First, surface integral equation is derived for the Oseen flow, and then, extended to the Navier-Stokes equations. In the latter case, the repetition of solving the surface integral equation is needed. The nonlinear terms in the Navier-Stokes equations are regarded as the Oseenlets distributed in the flow field, and surface stresses are obtained numerically. As an example, the flow past a two dimensional flat plate is solved. The numerical results are coincident with the experimental data for the Reynolds number less than 100. But the proposed method is not efficient for high Reynolds number flow, because it is based on the Oseen solutions. This technique can be applied to the three dimensional flow past an arbitrary body, and expected to make up the Reynolds number region between the Oseen flow and boundary layer approximation.
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Kohzaburo NAKABAYASHI, Yutaka MIYAKE, Tyusei AOI
1985 Volume 51 Issue 467 Pages
2351-2357
Published: July 25, 1985
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In this report, the factors that are responsible for the accuracy of numerical caclcuratins of two-dimensional low Reynolds number flows around cylindrical bodies immersed in a uniform stream on the basis of Navier-Stokes equations are descussed. The finite difference calculations have been carried out for a circular cylinder and it has been confirmed that the differnnce of the outer boundary conditioin affects little on the accuracy, if the outer boundary is sufficently far from the body, but if a comparatively near outer boundary is assumed, Oseen flow is recommended as the outer flow on the boundary. The results can be extended to the other geometries of cylinders and Imai's asymptotic solution can be avilable in place of the Oseen flow. Some aspects of the flow, such as streamlines, length of twin-vortices, angle of flow separation, etc. are also descussed.
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Ryuhei YAMAGUCHI
1985 Volume 51 Issue 467 Pages
2358-2364
Published: July 25, 1985
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In this paper abnormalities in the exchange of substance from flulid to wall of a narrow rectangular stenosed channel have been studied. The transfer of a substance such as oxygen is modelled, and is numerically estimated by calculating the nonlinear diffusion equation. Furthermore, both local and mean mass transfer coefficient at the rear wall of the stenosis are measured by the electrochemical technique, in which a redox system comprises the electrolyte and the test nickel electrode. Measurements are conducted in the Reynolds number range of 100-300 and a Schmidt number of about 1000. Consequently, the local mass transfer are maximum near a reattaching point, asymptotically decrease at the downstream wall of this point and steeply decrease at the upstream wall of this point. At R
e > 130 the mean mass transfer at the rear wall adjacent to stenosis is lower than that away from stenosis.
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Shin TAKABATAKE, Kyozo AYUKAWA, Mitsuru OKURA
1985 Volume 51 Issue 467 Pages
2365-2372
Published: July 25, 1985
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The Navier-Stokes equations are solved numerically for two-dimensional perstaltic flows by using the finite-difference technique employng the upwind SOR method, and pumping characteristics of peristaltic transport are studied. The energy transfer in the flow and the mechanical dfficiency of the peristaltic pumping are analyzed in this paper, for a wide range of wave amplitudes, wavelengths and Reynolds numbers. The effectts of variations of these parameters on the pumping characteristics are investigated. And the trapping phenomenon which is an peculiar pattern in the peristaltic are also investigated in detail, in order to study the contribution of the trapping to the hydrotransport of peristaltic pumping. As a result, it is found that the pumping efficiency is caused to increase remarkably by increasing of wave amplitude, but is slightly reduced by the effect of fluid inertia as Reynolds number increases.
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Hideo OHASHI, Hidenobu SHOJI, Chisachi KATO
1985 Volume 51 Issue 467 Pages
2373-2381
Published: July 25, 1985
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Flulid forces on a rotating centrifugal impeller in whirling motion were studied experimentally. A two-dimensional impeller installed in a parallel-waved vaneless diffuser was forced to circular orbital motion with various positive and negative angular speeds. The results showed that the fluid forces exert a damping effect on the rotor at most operationg conditions, but become excitatory when the impeller operates at partial discharge and rotates far faster than the whirl speed. The test result was compared with theoretical one and quantitative agreement was obtained especially in positive whirl. Fluid forces were also expressed in terms of mass, damping and stiffness matrices.
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Shigenori MATSUNAGA, Mitsuo UNO, Tadashi TSUKAMOTO, Hiroshi TSUKAMOTO
1985 Volume 51 Issue 467 Pages
2382-2389
Published: July 25, 1985
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Using a five-hole pitot-tube with quick response, both upstream and downstream flow fields of a mixed-flow pump impeller were measured in order to make clear the hydraulic losses which arise in the fluid flow through an impeller. The hydraulic loss distributions at the downstream of the impeller were presented for two different specific speed impellers. The measured loss distributions were compared with the ones calculated by a simple prediction method. Moreover, the slip factors at impeller exit were also compared with the ones calculated by the existing formulae. As a result of the study, it was made clear that the ratio of the pressure rise by cascade effect to the one by centrifugal force effect is an important factor for the reasonable prediction of the hydraulic losses caused by a mixed-flow impeller.
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Teruo MIYAZAKI, Naomichi HIRAYAMA
1985 Volume 51 Issue 467 Pages
2390-2396
Published: July 25, 1985
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Detailed theoretical and numerical methods of a mass-averaged and pitch-averaged meridional through introduced in our solution in the preceding report are predicted. The solution for a mean flow may consider secondary flows effects by means of conformal mappings of a twisted S 1 stream surface onto an axisymmetoric one and then deal with complicated flows such as those through twisted passages with inlet distortion. Basic relations for the assumed S 2 relative stream surface are reduced to a singular integral equation which fully depends on pseudo-analytic function theories, and solved rigorously. Then itemized numerical method for the solution is showed just the same way as that for S 1 relative stream surface in the report. Owing to the existence and and uniqueness of a solution of the equation successive iteration is used. A numerical example is presented and the computation procedure is clear and easy to accomplish.
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Tomitaro TOYOKURA, Shiro AKAIKE, Akira NISHIKAWA, Toshiaki KANEMOTO
1985 Volume 51 Issue 467 Pages
2397-2405
Published: July 25, 1985
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This study is intended to get a desirable guide vane profile for a reversible pump-turbine. The effct of the guide vane profile on the flow through the double circular cascades composed of the guide vanes and the stay vanes was investigated theoretically based on the singularity method. The stay vane profile and the arrangement of two cascades are the same as those of the previous report. Experiments for the selected guide vanes were carried out for the turbine and pump modes in an air flow. On the turbine mode, the flow loss through the cascades decreases considerably compared with the previous result. The experimental results for the pump mode are also presented.
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Michihiro NISHI, Shigenori MATSUNAGA, Katsuhiko NISHITANI, Takashi KUB ...
1985 Volume 51 Issue 467 Pages
2406-2413
Published: July 25, 1985
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Theoretical and experimental studies were carried out to clarify flow-related mechanisms of pressure surges, which corresponded to violent pressure fluctuations observed in the elbow type draft tube of a Francis turbine at partial load. From analysis of pressure fluctuations, it is shown that a synchronous surge is regarded as the resonant condition of the gas volume in a cavitated spiral vortex core to the oscillation of pressure recovery caused by precession or rotation of the core in the bend inlet. The theory indicates that a rotating pressure surge occurs in a conical draft tube. This is proved by the experiments.
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Hideo INABA, Takeyuki FUKUDA, Masahiro SUGAWARA
1985 Volume 51 Issue 467 Pages
2414-2419
Published: July 25, 1985
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This experimental study concerns the mixed, forced and natural convection heat transfer in rectangular cross-section cavities heated from bottom surface. Flow visualization, temperature profiles and measurements of heat transfer from bottom heating surface are performed for various free-stream velocities, temperature differences between the free-stream and the heating surface and dimensions of the cavity. It is found that flow pattern and amount of convective heat transfer are influenced by an interaction between forced and natural convection, and there is an existence of Reynolds number's region which the amount of convective heat transfer is decreased with increasing Reynolds number. This paper correlates the experimental data in terms of Nusselt number, dimension ratio of cavity (depth/width of cavity), Grashof and Reynolds numbers according to the region of Reynolds numbers.
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Tamotsu IGARASHI, Yasuhisa IIDA
1985 Volume 51 Issue 467 Pages
2420-2427
Published: July 25, 1985
Released on J-STAGE: March 28, 2008
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Experimental studies on fhe fluid flow and heat transfer around a circular cylinder with vortex generators were carried out in the range of subcritical Reynolds numbers. According to the height of vortex generators and the Reynolds numbers, four flow patterns were found in connection with the transition in the boundary layer and flow separation. The local and average heat transfer on the rear surface vary with the values of the drag coefficient, the rms fluctuating pressure and the reciprocal of Strouhal number. The heat transfer coefficients at the rear stagnation point for four patterns are related to the Strouhal number by N
<ur> /R
<2/3>
e= 0.018/S
<1.4 >, within an error of 10%, and also to the rms fluctuating pressure at the rear stagnation point, ΔP
r, h
r ∝ ΔP
<0.31>
r.
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