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Risaburo OBA, Yukio ITO, Jiro HIGUCHI, Satoru NOZAKI, Tadashi ISHIGE, ...
1986 Volume 52 Issue 473 Pages
3-9
Published: January 25, 1986
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Seiichi WASHIO, Tadataka KONISHI, Katsuhiko TAMAI
1986 Volume 52 Issue 473 Pages
10-17
Published: January 25, 1986
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Seiichi WASHIO, Tadataka KONISHI
1986 Volume 52 Issue 473 Pages
18-24
Published: January 25, 1986
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Hideo OSAKA, Hidemi YAMADA, Yoshiro KAGEYAMA, Isao TERUYA
1986 Volume 52 Issue 473 Pages
25-33
Published: January 25, 1986
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Yasuki NAKAYAMA, Hirohiko OGINO
1986 Volume 52 Issue 473 Pages
34-42
Published: January 25, 1986
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Motoyoshi TACHIBANA, Nobuyoshi KAWABATA, Hirokazu GENNO
1986 Volume 52 Issue 473 Pages
43-49
Published: January 25, 1986
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Tomitaro TOYOKURA, Toshiaki KANEMOTO, Moriaki HATTA
1986 Volume 52 Issue 473 Pages
50-58
Published: January 25, 1986
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Toshiaki KANEMOTO, Tomitaro TOYOKURA
1986 Volume 52 Issue 473 Pages
59-67
Published: January 25, 1986
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Toshiaki KANEMOTO
1986 Volume 52 Issue 473 Pages
68-75
Published: January 25, 1986
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Toshiaki KANEMOTO, Tomitaro TOYOKURA, Toshio SUZUKI, Kimio KURATA
1986 Volume 52 Issue 473 Pages
76-84
Published: January 25, 1986
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Hideo INABA, Takeyuki FUKUDA
1986 Volume 52 Issue 473 Pages
85-93
Published: January 25, 1986
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Hideo INABA, Takeyuki FUKUDA
1986 Volume 52 Issue 473 Pages
94-101
Published: January 25, 1986
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Takao KAWAMURA, Masumi ITO, Ikuo MABUCHI, Masaya KUMADA
1986 Volume 52 Issue 473 Pages
102-109
Published: January 25, 1986
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Akio SAITO, Yoshio UTAKA, Kotaro SHINODA, Kozo KATAYAMA
1986 Volume 52 Issue 473 Pages
110-116
Published: January 25, 1986
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Toshiyuki KUROYANAGI
1986 Volume 52 Issue 473 Pages
117-125
Published: January 25, 1986
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Toshiyuki KUROYANAGI
1986 Volume 52 Issue 473 Pages
126-134
Published: January 25, 1986
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Masaaki OKADA, Koichi WATANABE
1986 Volume 52 Issue 473 Pages
135-143
Published: January 25, 1986
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Akio SAITO, Yoshio UTAKA, Masamitsu TSUBOTA, Norihiro MIZOHATA, Kozo K ...
1986 Volume 52 Issue 473 Pages
144-150
Published: January 25, 1986
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Satoshi KUMAGAI, Gie Shi, Yoichi HIRONO, Ryohachi SHIMADA, Toshiro TAK ...
1986 Volume 52 Issue 473 Pages
151-158
Published: January 25, 1986
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Kengo SASAGUCHI, Hideaki IMURA, Hiroichi FURUSHO
1986 Volume 52 Issue 473 Pages
159-166
Published: January 25, 1986
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Kengo SASAGUCHI, Hideaki IMURA, Hiroichi FURUSHO
1986 Volume 52 Issue 473 Pages
167-173
Published: January 25, 1986
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Akio SAITO, Yoshio UTAKA, Yasuhiko SAITO, Kozo KATAYAMA
1986 Volume 52 Issue 473 Pages
174-181
Published: January 25, 1986
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Kunio HIJIKATA, Tien C.L., Nobuhiro HIMENO
1986 Volume 52 Issue 473 Pages
182-189
Published: January 25, 1986
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Masahiro HIRANO, Toshio MlYAUCHI, Yasuo MORI
1986 Volume 52 Issue 473 Pages
190-198
Published: January 25, 1986
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Tohru FURUKAWA, Kotohiko SEKOGUCHI
1986 Volume 52 Issue 473 Pages
199-207
Published: January 25, 1986
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Yasuyuki YOKONO, Tsutomu GOMI
1986 Volume 52 Issue 473 Pages
208-214
Published: January 25, 1986
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Yukio HOHSHO, Toshikazu KADOTA, Ken KADOWAKI, Kazuhito MAKINO, Satoshi ...
1986 Volume 52 Issue 473 Pages
215-221
Published: January 25, 1986
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Hiroyuki HIROYASU, Masataka ARAI, Kazuo NAKANISHI
1986 Volume 52 Issue 473 Pages
222-229
Published: January 25, 1986
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Hiroyuki HIROYASU, Masataka ARAI, Kazuo NAKANISHI
1986 Volume 52 Issue 473 Pages
230-237
Published: January 25, 1986
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Toshiaki YANO, Kenichi ITO, Toshio TAKAHATA
1986 Volume 52 Issue 473 Pages
238-247
Published: January 25, 1986
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Hisaaki DAIGUJI, Satoru YAMAMOTO
1986 Volume 52 Issue 473 Pages
248-254
Published: January 25, 1986
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An implicit time-marching finite-difference scheme is proposed for analysing steady two-dimensional inviscid transonic flows. The scheme is based on the well-known Beam-Warming delta-form approximate factorization scheme, but this is improved on the following two-points : (i) In order to treat the fixed wall boundary condition without difficulty, momentum equations of contravariant velocity components as fundamental equations in curvilinear coordinates are used. (ii) To calculate stably with a sufficiently large Courant number, the central-difference of the Crank-Nicholson method is raplased by the upstream-difference of the Robert-Weiss method. The upstreaming is performed on the basis of the theory of characteristics and does not influence the accuracy of the solution. The flows through a converging-diverging nozzle and over a symmetric wing are calculated. The calcutated results agree well with the existing theories.
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Junichi KUROKAWA, Toshiyuki UCHIDA, Toshiaki ADACHI, Takeshi YAMADA
1986 Volume 52 Issue 473 Pages
255-260
Published: January 25, 1986
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The pipe flow of highly viscous fluid, of which wall is heated or cooled at a constant temperature, was studied theoretically and experimentally in order to determine the frictional resistance of the flow with the viscosity gradient. Measurements were performed for the Reynolds number 20<R
e<850, the Prandtle number 500<R
r<2400 and the temperature difference between the fluid and the wall -40°<ΔT<40°C. The result show that the theoretical analysis, taking into account a local viscosity gradient, gave good agreement with the measurements when the buoyancy effect is small. Also, that the pressure drop in the flow direction is little influenced by the buoyancy and is well predicted by the theory. The pressure drop increases almost linearly in the measured range and the friction coefficient, when the wall is heated or cooled, was expressed by a simple empirical equation. The velocity measurement by Pitot probes in the low velocity range was also carefully examined, and the influence of temperature was determined.
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Kimitaka HIRANO, Masanori KIKUCHI, Yutaka SUENAGA, Minoru MATANO
1986 Volume 52 Issue 473 Pages
261-265
Published: January 25, 1986
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The frequency of vortex shedding from two flat plates normal to a stream is experimentally investigated in various staggered arrangements at a Reynolds number of 2.60 ×10
4. The Strouhal number of vortex shedding varies widely from 0.067 to 0.343 for the upstream flat plate, and from 0.067 to 0.170 for the downstream flat plate. Four kinds of discontinuities in Strouhal number distributions are found. Flow visualizations suggest that wake widths behind the flat plates and path lines of shedding vortexes have an important influence on discontinuities of the Strouhal number. As long as distances between two centers of flat plates are larger than 2 chords, the wake Strouhal number, defined by the wake width, nearly equals that for a single flat plate, 0.156.
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Masaru KIYA, Masanori MATSUMURA
1986 Volume 52 Issue 473 Pages
266-275
Published: January 25, 1986
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The dispersion of velocity fluctuations, and its effect on phase-averaged properties of a two-dimensional vortex wake behind a normal plate, were studied both experimentally and by a numerical analysis. Reynolds number, based on the main-flow velocity and the height h of the plate, was 2.3 ×10
4. Measurements were made at 8h downstream of the plate. The dispersion was defined as a deviation from phase-averaged velocities, and was interpreted as being caused by random fluctuations of length scale, strength, position, shape, etc. of the shed vortices passing a section normal to the main-flow direction χ. The dispersion was found to contribute to most of the Reynolds shear stress and energy of the velocity flucations. General features of loci of constant energy and cross product of velocity fluctuations in the (χ, t) space-time domain, t being time, were almost independent of a condition of the phase-averaging, which was given in terms of the standard deviation of the vortex-shedding period. Moreover, the overall Reynolds shear stress and the energy were only weakly dependent on the condition. A numerical analysis simulating the dispersion by a two-dimensional fluctuation of position and strength of the vortex around the phase-averaged values, suggested that such fluctuations were not major agent of the dispersion, and the dispersion was probably associated with a two-and/or three-dimensional deformation of the vortices.
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Shingo ISHIZAWA, Tooru WATANABE, KOJI TAKAHASHI
1986 Volume 52 Issue 473 Pages
276-284
Published: January 25, 1986
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This paper analyizes an unsteady viscous incompressible fluid flow between two parallel disks. The gap-width between the two disks in varied arbitrarily with time, and a fluid source is located at the center of one disk. The Navier-Stokes equations have been solved using a new "multifold power series" expansion method. Experiments were carried out for the case of the sinusoidal gap-width variation, and the theory is in good agreement with the experimental result. Especially, it is noted that the theory can describe precisely the effect of a non-linear interaction between the two flows due to the gap-width variation and to the central fluid source.
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Seiichi TANIGUCHI, Katsumi MIYAKOSHI, Seiji DOHDA
1986 Volume 52 Issue 473 Pages
285-289
Published: January 25, 1986
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The characteristics of the fluctuating pressures on the surfaces of a two-dimensional square cylinder, and the approaching free turbulent mixing flow to the cylinder were experimentally investigated when the cylinder was placed in two sections of the free turbulent mixing layer. The power spectrum and cross-correlation of the fluctuating pressures on the upper and lower surfaces were larger at η≃-0.32 and -0.1, where the fluctuating pressure attained their maximun values. It was also found that the flapping of the mixing layer was induced by the vortexes shedding from the cylinder and made these vortexes intense particularly at the above positions.
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Hiroshi SAKAMOTO, Hiroyuki HANIU
1986 Volume 52 Issue 473 Pages
290-297
Published: January 25, 1986
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Characteristics of arch-type vortex formed behind a plate of aspect ratio h/w = 0.8 (h: hight, w: width) which is placed vertically in a laminar boundary layer had been investigated. Flow visualization and analysis on velocity signals yielded following some new under standings. (i) The variation of Strouhal number S
t (=f
cw/U
0) with Reynolds number R
e (=wU
0/v) can be classified into three regions. (ii) Arch-type vortex formed behind a plate shows inconsistency in its periodicity and strength, and have no regular mode vortex shedding like two-dimensional circular cylinders. (iii) Different tendency of Strouhal number distribution for Reynolds number is due to the different time rate of intermittent vortex shedding. (iv) Arch-type vortex formed behind a plate starts to dissipate in the very vicinity of the downstream of the plate before convected to far downstream.
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Mutsuo KOBAYASHI, Hiroshi MAEKAWA, Tsuyoshi TAKANO, Shinji HIRATSUKA
1986 Volume 52 Issue 473 Pages
298-304
Published: January 25, 1986
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When a cylinder is placed perpendicular to a uniform flow of fluid, the upstream velocity vector can be determined from the velocities measured at two points in the region where the streamlines are deformed by the cylinder. Based upon this principle, a new type of probe, which possesses similar directional sensitivity to an X-probe and is suitable for anemometry in a narrow space, has been devised. Since the hot-wires are put outside the boundary layer on the cylinder, the optimal location for each wire can be examined by analysing the sensitivities for the probe operating in a plane inviscid flow. The probe, with a cylinder of about 0.1 mm in diameter, is calibrated statically and dynamically, and applied to measuring turbulent stresses and power spectra in simple flows. The experiment shows that this type of probe is reliable in various measurements of gaseous turbulence.
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Tyozi HORIKOSHI, Toshihiko IKEDA, Itiro ASANO
1986 Volume 52 Issue 473 Pages
305-311
Published: January 25, 1986
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This paper describes the vortex behaviour formed in the shear layer of the rectangular jet. Introducing the momentum thickness in the shear layer of the jet, the relation the Strouhal number of the jet breakdown and the velocity profile is uniform, the Strouhal number of the jet breakdown is a constant regardless of the Reynolds number. When the profile is nearly parabola, the Strouhal number increases with the Reynolds number. In addition, the relation between the wave-form of the velocity fluctuations and the frequency spectra, as well as flow visualization is investigated. When the vortex coalescence has occured, the wavelength is doubled and the frequency is halved.
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Hideo OSAKA, Hidemi YAMADA, Shigehiro HANO, Yoshiro KAGEYAMA
1986 Volume 52 Issue 473 Pages
312-317
Published: January 25, 1986
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The Fluid flow through woven screens in a circular pipe was measured to determine the resistance of those woven screens under the steady state. The screens included in this study are eighteen screen made of round wire forming a square mesh. Results show that after passing through all plain square screens, the velocity profiles represent three different patterns based on the coefficient of porosity β. The relationship between the resistance coefficient K and the wire diameter Reynolds number can be classified into three classes according to the three different patterns of the velocity profile. The use of the average velocity U/β and pore spacing l as a characteristic velocity and scale makes a more general correlation between the resistance coefficient and the Reynolds number. The relation between K and β depends on the wire diameter Reynolds Number.
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Nobuo OGAWA, Hiroshi MAKI
1986 Volume 52 Issue 473 Pages
318-324
Published: January 25, 1986
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In axisymmetrically opposed jets, it has been asserted that the location of the impinging surface was determined mainly by two opposed-nozzle exit momentums. It was shown in the 1st report that pressure fluctuations on the axis of the opposed jets play an important part in determining the location of the impinging surface. In the present paper, in an opposed jet flow, the mechanism to determine the location of the impinging surface is elucidated by experimental results of the usual turbulent impinging jet on a plate, instead of the impinging surface. In the flow between the nozzle and the impinging plate, mean velocity distributions and total pressure distributions, it is ascertained that kinetic energy transportation is influenced very much by the existence of a body, for instance, a slender bar, on the axis of the impinging jet.
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Kazuyuki SHIZAWA, Takahiko TANAHASHI
1986 Volume 52 Issue 473 Pages
325-333
Published: January 25, 1986
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A new complete set of basic equations for magnetic fluids having good conductivity of heat and electricity with internal rotation has not been derived before. In this paper, governing equations for such conducting magnetic fluids are formulated by the thermodynamical method, in which free energy and the dissipation function are used on the basis of kinematical balance equations in the polar theory. A simple method for determining a constitutive equation of magnetization is proposed, so that the relaxation equation of magnetization becomes unnecessary. It is shown that the equations obtained in this paper involve almost all equations concerned with magnetic fluids. The new system of equations for nonconducting magnetic fluids derived here is more general and strict in comparison with those previously presented. Hence, it will be possible to treat rapid changes of magnetic fields by the present theory.
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Hiroshi KOBAYASHI, Tadao TORISAKI, Mitsuo MORITA, Hiroharu TAKAGI
1986 Volume 52 Issue 473 Pages
334-344
Published: January 25, 1986
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The clarification of fan noise variations due to a flight effect is important for turbofan engine noise reductions and noise estimations. Therefore, the fan noise spectrum extent and the range of fan operating condition which are affected by flight effect were studied experimentally, with a turbofan engine and an inflow control device which can simulate a flight effect on fan noise in static test conditions. The fan noise reduction due to flight effect in the fan approach condition is bigger than that in the fan take-off condition, for a fan rotor aerodynamic loading generates BPF tones near take-off condition. The biggest reduced component in fan noise spectrum is a 1st fan BPF tone, whose level is 20 dB at maximum. Higher harmonic BPF tones and a buzz saw noise are also reduced due level is 20 dB at maximum. Higher harmonic BPF tones and buzz saw noise are also reduced due to flight effect, but the reduction of broadband noise is not founded in all ranges of fan operation.
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Atsushi KUROSAWA
1986 Volume 52 Issue 473 Pages
345-350
Published: January 25, 1986
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A spray spurted from a swirl atomizer takes the form of a hollow cone, with the dispersed spray becoming sparse in the vicinity of the center axis. In order to improve the performance, a reformed atomizer which has an orifice at the center of the swirl element was prepared for trial. The spray performance, especially the influence of the center jet issuing into the cavity formed in the vortex chamber, was investigated. As a result of the study, it was recognized that the atomizer offers a remarkable improvement of the atomizing characteristics, such as the uniformity of spray distribution and droplet size.
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Michio SADATOMI, Yoshifusa SATO
1986 Volume 52 Issue 473 Pages
351-357
Published: January 25, 1986
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Fully developed two-phase air-water flows through a multiple channel consisting of two interconnected subchannels were investigated. The purpose was to obtain more reliable data on the flow distributions when the cross-sectional area of the subchannels is different. Five test sections were used. The three of them were rectangular ones aligned vertically, and their area ratio of the subchannels were 1.5, 2 and 3.. The two others had the semi-circular subchannels of the area ratio 1.5 ; one was arranged horizontally while the other vertically. Void drift phenomena have been observed not only in vertical flows but also in horizontal flows. A more prominent void drift took place in a slug flow while less pronounced in a bubble flow and an annular flow. It was seen that the channel geometry has very little effects on the flow distributions and the flow pattern transitions. This supports the so-called one dimensional subchannel analysis in such a multiple channel.
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Tamotsu IGARASHI
1986 Volume 52 Issue 473 Pages
358-366
Published: January 25, 1986
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Experimental studies have been made to examine the effect of tripping-wires on the transition in a boundary layer on a circular cylinder in a cross flow. The flow patterns are divisible according to the angle φ
R, a contact point of the tangent to the cylinder from the top of the roughness, and to the roughness Reynolds number R
ek, defined by the height of the roughness and the outer edge of the boundary layer. In the range of φ
R≥70°the roughness has no influence on the transition up to R
ek≥1220, it is fully effective for the transition. In this case, the Strouhal number S increases to 0.30 and the drag coefficient C
D decreases to 0.60. In the range of 70°≤φ
R≤75°, the transition occurs at R
ek=620. Beyond φ
R=76°, the flow is separated by the roughness, and the values of S and C
D are about 0.175 and 1.55, respectively.
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Yoshiyuki NAKASE, Junichiro FUKUTOMI, Hirotaka IIDA
1986 Volume 52 Issue 473 Pages
367-371
Published: January 25, 1986
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In this paper, we propose the use of a cross-flow turbine for e tidal or wave power plant. This turbine can rotate in the same direction, even in reciprocating water or air flows produced by an oscillating water flow. This turbine has two symmetrical nozzle shapes around its axis. In order to investigate the feasibility of this kind of turbine the expriments were carried out in steady water flow. It is presented that the symmetrically shaped turbine can rotate in the same direction in reciprocating flows. A vortex is formed inside the runner similar to a cross-flow fan and asymmetry flow is produced. Its efficiency is about 54%. Improvement is expected by use of the experimental data for the condition inside the turbine.
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Yoshihisa KAMADA, Sumio YAMAGUCHI, Kazuto SASAKI, INOUE Masahiro
1986 Volume 52 Issue 473 Pages
372-378
Published: January 25, 1986
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The "vortex design" method applied to an axial flow compressor stage has been extended to a diagonal flow impeller with high specific speed. For a given type of vortex flow, the through flow problem is solved by the streamline curvature method, and a blade element is determined on the basis of this solution. However, for any vortex type expect free vortex, an exit flow condition changes due to a secondary flow induced by vortices shed from the trailing edges. The given vortex type can be obtained by correcting this effect with a so-called secondary flow theory. The validity of this method has been examined in experiments for three kinds of vortex flow : free vortex type and constant tangential velocity types with or without correction of the secondary flow effect.
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Kenji KANEKO, Toshiaki SETOGUCHI, Shigemi HAYASHI, Masahiro INOUE
1986 Volume 52 Issue 473 Pages
379-385
Published: January 25, 1986
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In order to improve the performance of a diagonal-flow fan with low loading, the effects of solidity and aspect ratio of rotor blading have been investigated experimentally. With a decreasing aspect ratio, the effective operating range expands remarkably in the region of the lower flow rate, and the total pressure and efficiency increase there. In the case of higher solidity, the flow coefficient at stalling point changes little, notwithstanding the total pressure increases, hence a dip in performance characteristics becomes large. From the view-point of stable operation, lower aspect ratio and solidity are desirable. In addition, the validity of the present design method, which is extended from that of a high loading diagonal-flow fan, is examined.
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Yasutoshi SENOO, Masahiro ISHIDA
1986 Volume 52 Issue 473 Pages
386-392
Published: January 25, 1986
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The authors' theory on the tip-clearance loss of centrifugal impellers is modified to include variation of gas density in the impeller. Furthermore, a relationship between two empirical parameters in the theory is derived to reduce freedom of adjustment. In order to compare experimental data in the literature with prediction, examination was made regarding accuracy of data and the way to determine the corresponding flow rates at different tip clearances. Fair agreement between data and prediction was observed. These examples demonstrated effect of various parameters on tip clearance loss as follows. The clearance loss of high pressure-ratio compressors is less than that of low pressure-ratio compressors if the tip clearance ratio at the impeller exit is given. The clearance loss becomes smaller as the flow rate is reduced and also at a reduced shaft speed in cases of high pressure-ratio compressors. The equations in the theory clearly show these tendencies.
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