Sample records for ryutai rikigakuteki kansho

  1. Fluid dynamic interface between hull and hydrofoil; Sentai to suichuyoku no ryutai rikigakuteki kansho ni tsuite

    Kataoka, K.; Ando, J.; Nakatake, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering


    For the high-speed ship with hydrofoil, it is important to grasp the mutual interference between its hydrofoil and hull. In this study, effects of the state of hydrofoils and velocity on the hull were fluid-dynamically investigated through the numerical calculation by means of Rankine source method using a Wigley model with two hydrofoils. Before considering the model with hydrofoils, the attitude change of a hull without hydrofoils during traveling in high-speed was examined. For the high-speed ship, various measuring systems have been conceived due to the large change in its attitude. The Wigley model has been used for the numerical calculation when considering the attitude change in the medium- and low-speed regions. In this study, resistance tests without constraining the sinkage and trim were conducted using a Wigley model in the high-speed region around Fn=1.0, which have not been usually conducted. The attitude changes were compared with the numerical calculation results by the Rankine source method. The wave making resistance and attitude change of the Wigley model with hydrofoils were also calculated. 12 refs., 10 figs.

  2. Experimental study on the control interaction force coefficient; Soju ryutairyoku kansho keisu ni kansuru jikkenteki kenkyu

    Nakatake, K.; Oda, K.; Yoshitake, A.; Fujita, K.; Nakajima, A. [Kyushu University, Fukuoka (Japan). Faculty of Engineering


    The interaction force induced to hull by steering is important for prediction of control performance of ships. The control interaction force coefficient dependent on the steering has been investigated through the rudder angle tests using three small model ships with a length of 2.5 m, i.e., mathematical type of ship, cargo type of ship, and tanker type of ship. The interaction forces acting on the hull, propeller, and rudder were determined by measuring the lateral force as well as the forward force of the hydrodynamic forces acting on the rudder. These forces were compared with the theoretically calculated values. Prior to the rudder angle tests, the self propulsion factor and the number of revolution of propeller were determined from the results of the open water tests, resistance tests, and self propulsion tests by the changing load method. The rudder angle tests were conducted under this number of revolution of propeller as a standard condition, and under those increasing and decreasing by 15%. Consequently, the interaction forces determined from the rudder angle tests agreed well with those determined from the other tests. When comparing the control hydrodynamic forces determined from the tests with those theoretically calculated, a similar trend was observed. Effectiveness of the theoretical model was confirmed. 4 refs., 14 figs., 3 tabs.

  3. Interaction effects on combustion of alcohol droplet pairs; Alcohol kei nenryo niekiteki no nensho ni okeru kansho koka

    Okai, K.; Ono, Y.; Moriue, O.; Shiba, S.; Araki, M.; Tsue, M.; Kono, M. [The University of Tokyo, Tokyo (Japan); Nomura, H. [Nihon Univ., Chiba (Japan). Coll. of Industrial Technology; Shiga, S. [Gunma University, Gunma (Japan). Faculty of Engineering


    Experimental investigation was conducted on two droplet-array combustion of methanol and methanol/dodecanol mixture fuels in microgravity. For methanol, effects of ambient pressure and droplet spacing were examined. Results show that the droplet lifetime decreases with increasing spacing at relatively low pressure and the droplet lifetime becomes independent of spacing at higher-subcritical and supercritical pressures. For methanol/dodecanol mixture, effects of pressure, fuel composition were investigated in terms of occurrence of disruption. Disruption of droplet during combustion was demonstrated both for single droplet and droplet pairs. (author)

  4. Data processing for the fluid flow tomography method; Ryutai ryudo den`iho no data kaiseki

    Ushijima, K.; Mizunaga, H.; Tanaka, T. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Hashimoto, K. [Kyushu Electric Power Co. Inc., Fukuoka (Japan)


    An automatic measurement system by means of conductive potential and self-potential methods (fluid flow tomography method) has been developed to measure the change of geothermal steam fluid during production and injection. For the fluid flow tomography method, the four-electrode configuration of the conductive potential method is adopted using the casing pipe of well as a current source. A lot of potential receiving electrodes are connected to the earth, preliminarily. The surface potential profile is measured, which is formed during the injection and production of the fluid through the well. Artificial and spontaneous potential profiles were continuously measured using this system during the hydraulic crushing tests at the test field of hot dry rock power generation at Ogachi-machi, Akita Prefecture. As a result of inversion analysis of self-potential data using a four-layer structural model of specific resistance, it was observed that the fluid injected at the depth of 711 m in the borehole permeated into the depth between 700 and 770 m in the south-eastern part of the well, and that the fractures propagated into the deeper part, gradually with the progress of hydraulic crushing test. 3 figs.

  5. Application of supercritical fluid to separation techniques; Chorinkai ryutai no bunri gijutsu eno oyo

    Minamino, Y.; Aki, T. [Mitsubishi Kakoki Kaisha Ltd., Tokyo (Japan)


    The application of supercritical fluid on separation techniques and its problems are reviewed. The application is at a standstill contrary to large expectation for it except component extraction from natural foods such as caffeine removal from coffee. Various problems are thus pointed out to be solved as follows; a study on new applications other than substitutional use for organic solvents, cost reduction, a study on new safe advanced fluids suitable for specific objects other than CO2, and combination with other several separation techniques. The new practical applications of supercritical fluid expected in the near future are as follows; low-cost mass production of antibodies by use of the immunity system of hens, drying of porous bodies intercalated in aqueous solution, removal of residual unreacted monomers and organic solvents from medical polymers, development of supercritical chromatographic equipment possible to separate pure functional food materials, and analytical extraction of functional groups including hetero atoms from harmful substances. 6 refs., 2 figs., 2 tabs.

  6. Control of mechatronic systems using electrorheological fluids; ER ryutai wo mochiita mekatoronikusu kiki no seigyo

    Furusho, J. [The Univ. of Electric Communications, Tokyo (Japan)


    ER fluids (electrorheological fluids) are fluids whose rheological properties vary due to an electric field, and at the present, its development is being vigorously carried forward with the objective of its application to various mechanical systems. The ER fluids which are the objects for its development are two kinds, namely ER suspensions and homogeneous fluids using liquid crystals. Concerning the ER suspensions, its study started from the latter half of 1940`s, but the history of studying the homogeneous ER fluids is short. In this article, comparison is made between the ER suspensions and the homogeneous ER fluids. Regarding the comparison in their application fields, several differences are enumerated including that the response time of the ER suspensions to the change of the electric field is considerably faster than the homogeneous fluids using liquid crystals. As examples of the application of the ER suspensions, ER valves, application to automobiles, ER dampers, vibration control of structures, and ER clutches are shown and likewise, as examples of the application of the homogeneous ER fluids, robot arm control, dampers, etc.. Also its application to robotics is described. 51 refs., 8 figs., 1 tab.

  7. Numerical estimation of interactions between foils and hulls of hydrofoil catamaran; Suichu yokutsuki sodosen no sentai to suichuyoku no sogo kansho

    Kataoka, K.; Ando, J.; Nakatake, K. [Kyushu University, Fukuoka (Japan)


    The hydrofoil catamaran model which is built up with the twin Wigley hulls and the tandem fore and aft set of hydrofoils is used for the numerical calculation and the experiments of this model was performed at Kyushu University. In this paper, combining with a Rankine source method, the SQCM (a simple panel method) is applied to the unsymmetrical flow problem around catamarans. And the running attitude of the model is not fixed in both the calculation and the experiments. Comparing with the experiment we show the interaction between hulls and the hydrofoils for the lift and the wave-making resistance in the high speed range. 6 refs., 11 figs.

  8. Advanced high temperature fluid technology development using microgravity environment; Bisho juryoku kankyo riyo kodo koon ryutai gijutsu kaihatsu



    Behavior of gas/liquid two-phase flow in tubes and behavior of air bubbles in liquid were investigated under the microgravity environment without convection by using the drop test facilities of the Japan Microgravity Center. To remove bubbles in the liquid under gravity, the strength of surface tension acting on the gas/liquid interface was made inhomogeneous. In this case, the moving velocity of bubbles on the gas/liquid interface was able to be raised up to the maximum of 2.4 mm/s. For the movement of bubbles in the horizontal direction under the condition of low relative velocity independent of the size of air bubbles in the duct, bubbles moving in the horizontal direction under 1g flowed almost linearly accompanying with the liquid flow. For the air bubble distribution in the bubble flow, where small bubbles flow in the vertical tubes, the fluid pattern of air bubble flow under 1g and {mu}g depended greatly on the initial condition of mixed bubbles. Fundamental data were obtained, as for the transportation and control of multicomponent bubbles, bubbles in the sound field, and bubbles in the liquid phase by magnetic force, and the fluid phenomena of bubbles in the subcool boiling region, a single bubble in the gradient electrical field, and bubbles in the tubes with small diameter. 47 refs., 97 figs., 8 tabs.

  9. Historical development of ERF and application to mechanical; ER ryutai no seigyo eno oyo to sono rekishi

    Saito, T. [Tokyo Engineering Univ., Tokyo (Japan); Sugimoto, N. [Ministry of Lab., Tokyo (Japan). Industrial Safety Inst.


    In this article, the history of research on ER fluids (electrorheological fluid-ERF) is briefly introduced and in commenting on its application to mechanical technology, the principle model of action of ER actuator and the improvement of control performance of pneumatic cylinder are explained as examples of application of the peculiar nature of ERF to control systems. In 1947, W. M. Winslow introduced for the first time a big viscosity change shown by ERF in his U.S. patent, since then this phenomenon has been called the Winslow effect. In 1960`s, the regular research of ERF started, reached its peak in 1970`s and in 1980`s its application to vibration control technology became flourishing. In this article, the properties of ERF, problematical points upon its application to equipment and the present state of ERF application studies are described. Furthermore, concerning the true merits of ERF as work output transistors, they are divided into the electricity-work output conversion property and the ERF transistor model for detailed explanation and the article ends up with the application of pneumatic cylinder to low velocity control. 19 refs., 9 figs.

  10. Study on solar collector utilizing electro-hydrodynamical effect; Denki ryutai rikigaku koka wo riyosuru taiyo shunetsuki no kenkyu

    Sato, M.; Aoki, H.; Wako, Y. [Hachinohe Institute of Technology, Aomori (Japan)


    This paper proposes a cone type electro-hydrodynamical (EHD) heat collector, describes its structure and principle, and mentions possibility of improving the heat collecting efficiency. The paper proposes a heat collector with a shape close to a cone. Trees are of cone form so that their every leaf, branch and truck can capture solar energy efficiently. Imitating this fact existing in the natural world, a cone-shaped heat collector was fabricated on a trial basis to discuss its heat collecting efficiency. Furthermore, black round stones are placed in the inner cone of the cone- shaped heat collector of double-glass structure. A low boiling point medium is placed between the inner and outer cones to cause corona discharge in vapor generated by absorbing the solar heat, and generate corona wind for an attempt to accelerate heat transfer into a heat exchanger. Thus, development was made on a cone-shaped high-efficiency heat collector utilizing electro-hydrodynamical (EHD) effect, and elucidation was given on dynamic phenomena of an electro-thermal fluid. Heat transfer in the EHD heat collector has a possibility of being accelerated by generation of ionic wind. In addition, it is thought that there would be an optimum value in applied voltage to increase electric charge supply as a result of corona discharge. 1 ref., 2 figs.

  11. Visualization of gas displacement and temperature distribution in the pulse tube; Parusukan nai deno ryutai no kyodo kashika

    Ito, S.


    It is important that measures and visualizes displacement and temperature distribution of the fluid to which vibrate in pulse service area of pulse tube refrigerating machine in order to attempt understanding and performance improvement of the refrigeration principle. Then, example of light measurement method of the fluid displacement using the sphere which the transfer possibly installed in pulse service area and measurement method of temperature distribution using the plane laser Rayleigh scattering method and each measuring result is outlined in this lecture. (NEDO)

  12. Analysis of uniaxial behavior of an Fe-based shape memory alloy under cyclic thermomechanical loading; Netsu rikigakuteki kurikaeshi fuka no moto deno tetsuki keijo kioku gokin no tanjiku henkei/hentai kyodo kaiseki

    Nishimura, F.; Watanabe, N.; Tanaka, K. [Tokyo Metropolitan Institute of Technology, Tokyo (Japan)


    The thermomechanical hysteretic behavior of an Fe-based shape memory alloy is phenomenologically analyzed under cyclic uniaxial tensile and compressive loading. The shift of the stress-strain-temperature hysteresis loop, expressed by means of the evolution of the residual strain, is well explained by the theory with some internal variables. The accumulated perfect dislocations formed as a result of the interaction of martensite plates is one of the internal variables introduced here. The back stress is also employed as an internal variable to be the driving force for the shape recovery for the martensite plates. The simulations describe well the hysteretic behavior under the strain and stress-controlled cyclic thermomechanical loading; the shift of a loop, evolution of the residual strain and the change in transformation stress. 21 refs., 10 figs., 1 tab.

  13. Baseline experiment of interferometric PGS at the EDM network in the south Kanto area, Japan. GPS kansho sokuiho ni yoru kisen sokuryo no kiso jikken (Minamikanto koha sokuryomo ni okeru hikaku kansoku)

    Kato, T.; Murata, I.; Matsumoto, S.; Hirata, Y.; Takahashi, T. (The University of Tokyo, Tokyo (Japan). Earthquake Research Institute); Tsuchiya, A. (National Space Development Agency of Japan, Tokyo (Japan)); Watada, S. (California Institute of Technology, California (USA)); Iga, A. (Sony Corp., Tokyo (Japan))


    The first field baseline observation using SONY GTT-4000, a GPS (Global Positioning System) interferometer was conducted at the EDM (Electromagnetic Distance Measurements) network of the Earthquake Research Institute in the southern Kanto Area, Japan. For the experiments, three GTT-4000 receivers of single frequency version were deployed at three sites which compose a triangle with side distances of about 8km, 12km, and 14km. The present paper introduces the receiver briefly, and the distances obtained by this receiver are compared with those obtained by the EDM observations. Consequently, it was shown that the results by GTT-4000 coincided well with those by EDM with less than 2ppm of accuracy. It was also shown that misclosures of the triangle which was obtained by the relative coordinate estimates were smaller than 1ppm. Furthermore, it was revealed that due to introduction of upgraded dual frequency capability, the receiver can reduce the effect of the ionospheric path delays. 5 refs., 4 figs., 2 tabs.

  14. Study of promotion of CO2 fixation by the environmental improvement in the coral reef area; Kansho chitai ni okeru kankyo kaizen ni yoru CO2 kotei sokushin no kenkyu

    Maruoka, T.; Ishitani, H.; Matsuhashi, R.; Yamada, K.; Komiyama, H.; Kraines, S. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering


    A study was conducted on how to fix CO2 in the ocean using coral reefs. Coral reefs have extremely high primary productivity ( production quantity of organic matters by photosynthesis) and are expected to be resources to fix CO2 when the quantity of photosynthesis exceeds the quantity of CO2 emitted in association with formation of calcium carbonate skeleton. If organic substances produced in coral reefs are well carried into the open sea, those are settled down on deep beds, which enables the storage into the ocean. At the coral reef floating in the ocean, it is not very deep inside and the seawater stays there, but it has a steep depth outside. By the numerical calculation, an examination was made on how the waterflow changes when making the flow path of seawater between the inland sea and open sea. From the actual calculation of an atoll, it was found that seawater comes in and out from the open sea to the inland sea near the opening of the atoll in accordance with the high tide and ebb tide, but the water stays at the deep bottom of the atoll. When installing a channel with a 10m depth at the portion where the water flows softly, the seawater was actively exchanged. 6 refs., 4 figs.

  15. Nonequilibrium molecular dynamics simulation of steady shear flows of Gay-Berne fluids; Gay-Berne ryutai no teijo sendan nagare ni taisuru hiheiko bunshi dorikigaku simulation

    Mori, N.; Nakamura, K. [Osaka University, Osaka (Japan)


    Numerical simulation was carried out by a nonequilibrium molecular dynamics method to clarify the system structure and rhelogical properties in the steady shear flow of the isotropic and nematic phases of liquid crystalline molecules. The F-GB potential (Lennard-Jones type that represents the model potential of liquid crystalline molecules and that has the dependency of orientation) that has both attractive force and repulsive force as the potential between molecules and the WCA-GB potential in which only repulsive force is considered were used. In an equilibrium system, it was known that the attractive force between molecules facilitates the phase transition of isotropic phase to liquid crystalline phase. In a shear flow, four systems between the isotropic and nematic phases were calculated, and the effect of the shear flow on each system was clarified. Moreover, the effect of the attractive force between the molecules in isotropic and nematic phases was investigated. The result showed that the attractive force between molecules influences the orientation order parameter of the system at a low shear rate. The degree of influence at that time differs in isotropic and nematic phases. 21 refs., 7 figs.

  16. Performance and regeneration of a pellet-packed-bed diesel-particulate trap; Ryutai jutenso diesel biryushi trap no seino oyobi saisei

    Shioji, M.; Nakai, S.; Ikegami, M. [Kyoto University, Kyoto (Japan); Hori, Y. [Yamaha Motor Co. Ltd., Shizuoka (Japan)


    This paper demonstrates with the feasibility of a pellet-packed bed for trapping diesel particulates. After making pellets loose from the packed condition, regeneration is established by a circulation of pellets in the trap and collected particulates are efficiently dropped out through the wire mesh on the bottom of the trap. An experimental trap with the pellet-circulation system using a spiral feeder is tested on a single-cylinder test engine to show the trap and regeneration efficiencies. In addition, the condition of pellet circulation is observed using the transparent cylinder, based on which the design of pellet and trap sizes are discussed. 6 refs., 10 figs.

  17. Numerical simulation of fiber suspension flow between parallel plates; Sen`i gan`yu ryutai no heiko heibankan nagare no suchi simulation

    Chono, S.; Makino, M. [Fukui University, Fukui (Japan). Faculty of Engineering


    Two-dimensional fiber suspension flow between parallel plates was simulated using the Dinh-Armstrong constitutive equation for semi-concentrated fiber suspensions. Sixth-order and fourth-order closure approximations were also evaluated. The velocity profile for the fiber suspension flow is flat compared with Newtonian flow, because the preferred angle for fibers is large in the channel center region, resulting in an increase in the local viscosity. The order parameter decreases and the preferred angle becomes large with increasing fiber concentration. The velocity field is accurately predicted by the equations with quadratic closure approximations used in this study, whereas the approximations do not provide satisfactory results for the orientation field. With respect to the order parameter, sixth-order closure approximation gives slightly less accurate predictions than fourth-order approximation. 22 refs., 13 figs.

  18. Research activities at thermo-fluid engineering laboratories in Takushoku University; Takushoku Daigaku kogakubu kikai system kogakuka ni okeru ryutai kogaku oyobi netsukogaku kankei no kenkyu

    Fujimoto, I.; Hori, M.; Matsunaga, N. [Takushoku University, Tokyo (Japan)


    This paper introduces general conditions of studies at the Machine System Engineering Department of the Faculty of Engineering at the Takushoku University. Studies related to transonic cascade flutters in fluid engineering include behavioral analysis of impact waves around vibrating blades. Behavior of impact waves making twisting vibration at high vibration frequency is elucidated by means of schlieren photography. In addition, the single blade vibration method is used to analyze aerodynamic decay properties of cascades. Elucidation is made on non-steady stalling properties of vibrating single blades (particularly, the hysteresis phenomenon of stalling elevation angles with restoring elevation angles). In the field of thermal engineering, studies are being made on effects of unburned components on NO-NO{sub 2} conversion using a fluidity reactor. Similar reactions are being studied by means of chemical dynamics calculations using the CHEMKIN-II/SENKIN program. A coaxial jet flow experimenting equipment is used to study NO{sub 2} generating mechanism in the field closer to real combustors. Data are accumulated to verify numerical computation by experiments and measurements of spraying flames produced by a model spray combustor. Measurements and experiments are also performed on absorption of NO{sub 2} into water, and on coefficient of diffusion between two kinds of gases. (NEDO)

  19. Fiscal 1995 research investigation on chemical process technology using supercritical fluid; 1995 nendo chorinkai ryutai wo riyoshita kagaku process gijutsu ni kansuru chosa kenkyu



    With relation to the supercritical fluid utilization technology, conducted in fiscal 1995 were collection of basic data, extraction of R and D subjects and survey/analysis of application fields based on the literature survey and overseas field survey. From the research results, the following were selected as research subjects: as to the clean/recycling process technology, non-selection cascade treatment process of mixed waste plastics, hazardous waste treatment process, and radioactive waste treatment process. As to the unused resource utilization process technology, the supercritical submerged combustion power generation process, heavy hydrocarbon resource reutilization process, biomass synthetic utilization process, and carbon dioxide reutilization process. As to the next generation reaction process technology, the simple reaction process, de-organic solvent process, chemical materialization process for methane, and reaction separation combined process. As the innovative material process technology, the plastic forming process, high-functional materials, high-efficiency energy conversion materials, and heightening of function of solid wastes. 537 refs., 116 figs., 54 tabs.

  20. Analysis of the pollutant in the environment using supercritical fluid chromatography (SFC); Chorinkai ryutai kuromatogurafui (SFC) wo mochiita kankyo chu no osen busshitsu no bunseki

    Kakuchi, T.; Miura, Y. [Hokkaido Univ., Hokkaido (Japan)


    The analysis of the organic pollutant in the environment is carried out as the following procedure; the organic substance is extracted by using the organic solvent from a collected sample, an instrument analysis such as gas chromatography (GC) or high performance liquid chromatography (HPLC) are done after the clean up the sample by column chromatography. The analysis using supercritical fluid instead of the organic solvent in each stage is supercritical fluid extraction (SFE) or supercritical fluid chromatography (SFC). The supercritical fluid has a density and viscosity coefficient between gas and liquid, and the control of the dissolving power is possible by the change of temperature and pressure. Therefore, it has the advantage as follows: The material mobile speed is high and separation and extraction are rapid; It is easy to adjust the dissolving power and possible to carry out selective separation and extraction; The removal of solvent can be easily carried out since supercritical CO{sub 2} used is a gas in the normal pressure. In this paper, the analytical instrument in which the extraction is carried out in organic solvent and clean up was done in SFC was introduced. (NEDO)

  1. Numerical analysis of viscoelastic start-up flow in abrupt contraction channel; Kyushukusho ryuro ni okeru nendansei ryutai no start up nagare no suchi keisan

    Yamamoto, T.; Nakamura, K. [Osaka University, Tokyo (Japan). Faculty of Engineering


    Start-up flows of viscoelastic fluids in a two-dimensional 4 to 1 abrupt contraction channel is numerically studied and the transient behavior of viscoelastic fluids is discussed. The multi mode Leonov model is applied to describe the rheological properties of the viscoelastic fluid. The numerical simulation has been carried out for two Weissenberg numbers. The following results are obtained from the present analysis: The corner vortices develop with time and restrict the velocity gradient to relax the growth of the stress field. The circular secondary flow works as a stress relief mechanism. The overshoot of the stress growth is observed at the high Weissenberg number and is not done at the low Weissenberg number. This phenomenon is caused by the unsteady elongational property of the fluid. 15 refs., 9 figs.

  2. Numerical calculation of viscoelastic flows through eccentric abrupt contraction; Henshin kyushuku shoryuro ni okeru nendansei ryutai no nagare no suchi kaiseki

    Nakamura, K.; Mori, N.; Matsumura, K. [Osaka University, Osaka (Japan). Faculty of Engineering


    Numerical simulations of viscoelastic flows through an eccentric four-to-one abrupt contraction are carried out using the Giesekus model. The SMAC (Simplified-Marker-and-Cell) method is used to analyze the three-dimensional flows. The velocity profiles along the path line passing through the center of the exit exhibit an overshoot near the entry section, and at high Weissenberg numbers an undershoot follows the overshoot. The magnitude of the stress along the same path line has a peak near the entry, section, and its slow relaxation process indicates that a large downstream length is necessary for fully developed stress conditions to exist. The peak is lower than that for the flow through the concentric four-to-one abrupt contraction ; the decrease in the peak amplitude is understood to be due to the distortion of the path line in the eccentric geometry. A corner vortex, the height of which is a maximum at the widest corner, grows as the Weissenberg number increases. Furthermore, the tangential flow toward the widest section inside the vortex is determined. 19 refs., 10 figs.

  3. Fiscal 1996 investigational research on the chemical process technology using supercritical fluids; 1996 nendo chorinkai ryutai wo riyoshita kagaku process gijutsu ni kansuru chosa kenkyu



    Importance was studied of making a research on the chemical process technology using the supercritical fluid. As for its effect on global warming, the amount of CO2 emission was compared during the operation between the conventional process and the process using the supercritical fluid, the CO2 reduction rate and amount were trially calculated, and a CO2 reduction of a several ten thousand ton scale in carbon conversion was predicted. As to hazardous materials and the reaction of waste retrieval, it was made clear that the process using the supercritical fluid was valid also for objects for which the chemical process used to be impossible, which indicates a possibility of the widening field of application. Concerning its effect on the energy conservation, energy reduction of several ten thousand tons in heavy oil conversion was predicted by replacing all the existing processes with supercritical fluids. Relating to the recycling, with the use of supercritical fluids, the process is possible which produces higher quality and yield and fewer unnecessary products such as char than the conventional process. 197 refs., 102 figs., 71 tabs.

  4. Electrorheological properties of silicon oil based fluid dispersing smectite particles; Smectite ryushi wo silicon yuchu ni bunsansaseta ryutai no electrorheology tokusei

    Fujita, T.; Kogita, H.; Obinata, G. [Akita University, Akita (Japan). Mining College; Yoshino, K. [Tokai Rubber Industries, Ltd., Aichi (Japan); Saiki, H. [Co-op Chemical Co. Ltd., Tokyo (Japan)


    Synthesized smectite particles have been dispersed in methylphenyl silicon oil. The prepared fluid is stable in a gravitational field. the viscosity of this fluid under electric field has been investigated by many parameters as follows, smectite content in silicon oil, shear rate, electric field strength, frequency of electric field or DC field, temperature of fluid, frequency on viscoelasticity, response time, stability and durability, and so on. The shear stress and current density have increased almost in proportion to a square of electric field strength. The dynamic modulus and dynamic loss change much more in the fluid dispersing lower smectite concentration by applying electric field. For the durability of fluid the viscosity is almost same for several hours under 2kV/mm. This fluid is expected to use in the damper, actuators and so on. 11 refs., 13 figs.

  5. Pressure response of electrorheological suspension in a model ER damper; ER damper model ni okeru bunsanke ER ryutai no atsuryoku oto

    Nakano, M.; Yonekawa, T. [Yamagata University, Yamagata (Japan). Faculty of Engineering


    This paper reports the examination result of the pressure response of an electrorheological suspension fluid (obtained when the particles of a strong acid ion-exchange resin are dispersed on silicon oil and whose rheological characteristics vary with the action in the external electric field) in an electrorheological (ER) damper model (experimental equipment consisting of an ER valve with plane parallel electrode and a piston cylinder). A rectangular wave voltage is applied to the ER valve to obtain the pressure fall components based on the steady ER effect of an ER fluid flowing between the plane parallel electrodes. The intensity of the electric field and the dependence on the flow velocity were formulated by an approximate function. The flow velocity dependency of this ER effect does not coincide with the theoretical analysis result based on a Bingham fluid model. The pressure in a cylinder presents the transient response of a first-order lag to the rectangular wave voltage input to the ER valve. The time constant value in this case can be explained by considering the compressibility of the residual air in the ER fluid. 11 refs., 11 figs.

  6. Application of streaming potential method for detection of fractures in granitic rock; Kamaishi kozan ni okeru ryutai ryudo den`iho tekiyo shiken

    Negi, T.; Yokoi, K.; Yoneda, Y. [Nittetsu Mining Co. Ltd., Tokyo (Japan); Senba, T. [Power Reactor and Nuclear fuel Development Corporation, Tokyo (Japan)


    Measurements were made using the streaming potential method for the purpose of investigating the expansion of hydration cracks, direction of their propagation, and the chaining of cracked surfaces, in the granitic rock. Tests were conducted by use of a bore hole in the gallery wall. The bore hole yielded approximately 400 liters of water per minute, the bore hole was closed and then opened, and the change with the passage of time in the spontaneous potential (SP) on the gallery wall was measured. At a spot 31.2m from the mine entrance, the SP dropped by 15mV simultaneously with the opening of the bore hole, and rose by 14mV simultaneously with the closure of the same. The phenomenon was true for other locations, that is, for the section from the mine entrance to a spot 9.0m therefrom, and for a section beginning at 15.0m and ending at 19.2m therefrom. No change in the SP was observed in a group of cracks with water springing out of the gallery roof, beginning at a point 40m and ending at a point 54m from the mine entrance. The result suggests the possible application of the streaming potential method to the investigation of cracks. 1 ref., 10 figs.

  7. Development of a new numerical method for visco-elastic flows using the GSMAC-method and the MUSCL-TVD method. Flows of Maxwell fluid through planer abrupt contraction; Kosei hoteishiki ni TVD gata MUSCL ho wo mochiita GSMAC ho ni yoru nendansei ryutai no kaiseki ni tekishita scheme kaihatsu. Maxwell ryutai no kyushuku shoheibannai nagare ni yoru kensho

    Fujieda, T.; Tanahashi, T.; Okada, A. [Keio University, Tokyo (Japan). Faculty of Science and Technology; Kato, Y. [Asahi Glass Co. Ltd., Tokyo (Japan)


    In this paper, we propose a new GSMAC-FEM (generalized simplified marker and cell-finite element method) which is suited to the numerical analysis of visco-elastic fluids. The equation of continuity and the equation of momentum are solved by the GSMAC-FEM algorithm and the constitutive equation is solved by the finite volume method. This scheme employs the third order MUSCL (Monotone Upstream-centered Schemes for Conservation Law) in order to guarantee the absence of spurious oscillation near the steep gradients of the variable. This method uses a minmod limiter in order to satisfy the TVD (Total Variation Diminishing) condition. The present method employs the simultaneous relaxation of velocity and pressure for the incompressible condition. The flows of Maxwell fluid through two-dimensional planer abrupt contraction are calculated by the present method and the effects the Weissenberg number and the Reynolds number are discussed. 13 refs., 12 figs.

  8. Study on a constant-tip-speed-ratio operation of wind power generation system. Effect of load control system on dynamic behavior; Furyoku hatsuden system no hensoku seigyo unten ni kansuru kenkyu. Fuka seigyokei ga system no rikigakuteki kyodo ni oyobosu eikyo

    Wakui, T.; Yamaguchi, K. [Waseda University, Tokyo (Japan); Tanzawa, Y. [Nippon Institute of Technology, Saitama (Japan); Hashizume, T.; Ota, E. [Waseda University, Tokyo (Japan). School of Science and Engineering


    The effect that the set data of the load control system in a wind power generation system exerts on the dynamic behavior of a system was investigated. The wind power generation system consists of a hybrid wind turbine with combined Darrieus and Savonius rotors, load with a generator and battery in the center, and a controller. A constant-tip-speed ratio operation that holds the circumferential speed ratio in which the power coefficient is maximized irrespective of the change in wind velocity was used to extract and convert the wind energy more effectively. In a high-wind velocity area, the system is operated at a fixed speed, and the increase in rotation is suppressed to protect the wing strength. In a large system, the response characteristics are only slightly improved by the limited load operation range and influenced rotor inertial. Power cannot be fully extracted even if the control system is changed in setting, and the applicability to the wind situation remains low. During the actual operation, the adjustment value of the control system should be set so that the output operation is satisfactorily possible in the specified load operation range, that is, the change in the instantaneous value of an effective power coefficient indicates almost flat gain characteristics in frequency characteristics. 14 refs., 10 figs., 2 tabs.

  9. Study of the development of high resolution sub-surface fluid monitoring system using Accurately Controlled Routine Operated Seismic Sources (ACROSS); Seimitsu seigyo shingen ni yoru chika ryutai koseido monitoring no kenkyu

    Kumazawa, M.; Ogawa, K.; Fujii, N.; Yamaoka, K.; Kumagai, H.; Takei, Y. [Nagoya University, Nagoya (Japan). Faculty of Science; Ishihara, K.; Nakaya, m. [New Energy and Industrial Technology Development Organization, Tokyo, (Japan)


    Fourier seismology capable of determining quantities related to elastic wave velocity dispersibility and non-elastic damping is under development, and studies are under way for the development of a sub-surface probing technology utilizing this seismology. It is deemed that the above-said quantities are related to the occurrence of earthquakes, behavior of sub-surface water, and migration of magma. In this method, precisely controlled sinusoidal waves are radiated and the received spectral data is subjected to cepstrum analysis, advantageous over other methods in that it achieves a high S/N ratio in a non-destructive way, facilitates deep structure analysis, and capable of monitoring changes with the elapse of time in such a structure. A newly-developed high-mobility transportable quake generator is described, which covers a wider frequency range and aims at the short-distance exploration of sub-surface conditions. Important components of the quake generator include an eccentric mass bearing capable of dealing with high-speed rotation enabling high frequency oscillation, variable mechanism for the primary moment of inertia, exciter and ground surface coupler allowing operations on a soft ground, and torque cancelling mechanism for the excitation of SH waves only. 3 figs.

  10. Drag and lift induced by the flow of viscoelastic fluids past a minute cylinder near a wall; Hekimen kinbo no bisho enchu wo sugiru nendansei ryutai no nagare ni yoru koryoku to yoryoku

    Watanabe, H.; Hasegawa, T.; Narumi, T. [Niigata University, Niigata (Japan). Faculty of Engineering; Tamano, K. [Mitsubishi Electric Corp., Tokyo (Japan)


    In detergent engineering and polymer processing, it is important to study the force exerted on an obstacle placed near a wall. In the present study, we numerically analyze the flow of viscoelastic fluids past a minute cylinder which is set at or near an inside wall of a two-dimensional channel. The upper convected Maxwell model and the finite-element method are used as the constitutive equation and the numerical method, respectively. Drag and lift of the cylinder are calculated for low Reynolds numbers (Re) and various Weissenberg numbers (Wi) of positive and negative values. Drag coefficient (C{sub D}) slightly changes with Wi. Lift coefficient (C{sub L}) monotonously decreases with increasing Wi irrespective of the sign of Wi. C{sub L} is greatly changed with Wi and is more sensitive to the elasticity of the fluid than C{sub D}. C{sub D} and C{sub L} decrease as the cylinder is separated from the wall. 11 refs., 12 figs.

  11. Numerical simulation of viscoelastic flow due to rotating disc enclosed in a cylindrical casing with large axial clearance; Kaiten enban ni yoru nendansei ryutai no yokinai nagare no suchi simulation (jikuhoko clearance ga hiroi baai)

    Ito, M. [Nagoya Institute of Technology, Nagoya (Japan). Faculty of Engineering; Moroi, T. [Toyoda Automatic Loom Works, Ltd., Aichi (Japan); Toda, H. [Toray Industries, Inc., Tokyo (Japan)


    Numerical simulations by a finite-difference method have been made for a viscoelastic flow due to a rotating disc enclosed in a cylindrical casing with large axial clearance. The Giesekus model with a single relaxation time was applied as a constitutive equation. We could simulate some typical secondary flow patterns for viscoelastic fluids which were different from Newtonian fluids; e.g., a secondary flow of which circulation direction at very low Reynolds number is reversed compared with that for a Newtonian fluid and a double-cell flow structure which Escudier et. all observed at relatively high Reynolds number. We show that the double-cell flow structure relates to nonlinear terms of the constitutive equation. The secondary flow patterns are characterized by the elasticity number (=Weissenberg number/Reynolds number) from low to high Reynolds numbers. 16 refs., 14 figs., 1 tab.

  12. Viscoelastic flow due to a rotating disc enclosed in a cylindrical casing. Numerical simulation and experiment; Kaiten enban ni yoru nendansei ryutai no yokinai nagare. Suchi simulation to jikken

    Moroi, T. [Toyoda Automatic Loom Works, Ltd., Aichi (Japan); Ito, M.; Fujita, K. [Nagoya Institue of Technology, Nagoya (Japan)


    Numerical simulations by a finite-difference method have been made for a viscoelastic flow due to a rotating disc enclosed in a cylindrical casing with relatively large axial clearance. The Giesekus model, modified Giesekus modal and Phan Thien-Tanner model were applied as the constitutive equations. Using particle tracking velocimetry (PTV), the effects of rheological properties on the distribution of the velocity component V{sub {theta}} and the secondary flow were clarified. By comparing the experimental results with the numerical simulations the validity of the respective viscoelastic fluid models were examined. The secondary flow patters observed by flow visualizations were characterized by the elasticity number (= Weissenberg number/Reynolds number). It was confirmed experimentally that near the rotating axis there was a place where the tangential velocity component was negative for the cases of 0.3 wt% and 1 wt% polyacrylamide aqueous solutions. (author)

  13. Measurement of temperature and thermal properties of fluid by detecting 1{omega} and 3{omega} components. 1st Report. Experimental study; 1{omega} 3{omega} keisoku ni yoru ryutai no ondo netsu busseichi keisoku. 1. Jikkenteki kenkyu

    Nakabeppu, O.; Yamamoto, N.; Kinoshita, A.; Hijikata, K. [Tokyo Institute of Technology, Tokyo (Japan)


    A method of measuring temperature and thermal properties of nonconductive fluids was experimentally studied, where 1{omega} and 3{omega} components of the voltage drop across a thin metal wire probe heated with an AC current of frequency {omega} were measured. The temperature distribution of a weak natural convection plume from a horizontal wire in water was visualized by this method and it was shown that background noise and self-heating of the probe limit the measurement resolution. Thermal conductivity measurements were performed for air, water, ethanol, etc. using a 10 {mu}m-diameter platinum wire, with applied AC frequency ranging from 0.1Hz-10kHz. Since mermaid conductivity is derived from the measured 3{omega} component by comparing with a thermal conduction model, the effect of natural convection from the probe itself was important and a restriction on applicability of the method was obtained in terms of the Rayleigh and Courier numbers. 4 refs., 8 figs., 2 tabs.

  14. Study of interaction of a pair of longitudinal vortices with a horseshoe vortex around a wing. 1st Report. Potential for passive controlling by a pair of vortex generators; Tsubasa mawari no bateikei uzu to tateuzu no kansho ni kansuru kenkyu. 1. Ittsui no uzu hasseiki ni yoru judo seigyoho no teian

    Hara, H.; Takahashi, M. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Ikeda, K. [Toshiba Corp., Tokyo (Japan); Shizawa, T.; Honami, S. [Science University of Tokyo, Tokyo (Japan). Faculty of Engineering


    This paper presents a potential for a passive control of a horseshoe vortex at the root of the wing. NACA0024 wing is established on a turbulent boundary layer. A pair of vortex generators of halt delta wing is installed upstream of the wing. The controlled horseshoe vortex is tested qualitatively by flow visualization technique. Also, the potential for controlling is quantitatively investigated by wall static pressure and total pressure. The horseshoe vortex is remarkably controlled in Common Flow Up Configuration (CFUC) of vortex generators. The distortion of the total pressure contours is diminished by 49% and the vortex is located closer to the wing. In case of Common Flow Down Configuration (CFDC), the mass flow averaged pressure loss is decreased by 29% compared with the case without a pair of vortex generators. (author)

  15. Study of interaction of a pair of longitudinal vortices with a horseshoe vortex around a wing. 2nd Report. Behavior of the interacting flow field controlled passively; Tsubasa mawari no bateikei uzu to tateuzu no kansho ni kansuru kenkyu. 2. Judo seigyosareta nagareba no kyodo

    Hara, H. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Shizawa, T.; Honami, S. [Science University of Tokyo, Tokyo (Japan). Faculty of Engineering


    This paper presents the behavior of a passively controlled horseshoe vortex at the root of NACA0024 wing which is established on a turbulent boundary layer, A pair of vortex generators of half delta wing is installed upstream of the wing. The flow field of the optimally controlled horseshoe vortex both in case of Common Flow Up (CFUC) and Common Flow Down Configuration (CFDC) is carefully investigated by an X-array hot-wire. In case of CFUC, the horseshoe vortex is not shifted from the wing, because the longitudinal vortex is restrained. The interacted vortex presents a circular profile, in a optimally controlled case. In case of CFDC, the interacted vortex that has strong vorticity by the pairing process is shifted away from the wing. Then, the high momentum fluid flow penetrates between the wing and the vortex. (author)

  16. Study on suppression acoustic resonance of interaction tones from a centrifugal motor blower. Modeling of phenomenon and proposal of suppression method; Enshingata sofuki ni okeru doseiyoku kansho ni kiin suru onkyoteki iyomei gensho no hasei genri to yokuseiho. Gensho no model ka to yokusei shuho no teian

    Sugimura, K.; Watanabe, M. [Hitachi, Ltd., Tokyo (Japan)


    In a centrifugal blower with diffuser vanes, the noise level may unexpectedly increase at certain numbers of revolutions. In particular, the phenomenon of acoustic resonance due to aerodynamic interaction tones between the impeller and the diffuser is a serious problem. In this paper, we develop a physical model to describe this phenomenon. The model assumes that inner flow paths both in the impeller and the diffuser behave as quasi-one-dimensional acoustic tubes. We constructed a mathematical model to predict critical numbers of revolutions at which resonance occurs, and conducted experiments to verify the model, and the results agree well with the mathematical model. We also propose an effective method for suppressing the resonance in which diffuser vanes with slits are used. Each diffuser vane has a slit located just behind the end of the facing area between neighboring vanes. The location of the slit is determined by the mathematical model. Experiments show that the method successfully reduces keen noise by as much as 8 dB. (author)

  17. Numerical modeling of historical change of volcanic heat sources: Numerical modeling of heat and mass transport up to 1000 degree C; Kazansei netsugen no keiji henka no shumyureshon kaiseki: 1000 degree C madeno netsu{center{underscore}dot}ryutai shumyureshon kaiseki

    Hanano, Mineyuki [JMC Geothermal Engineering Corp., Iwate (Japan)


    Temperature structure and its historical change around volcanos has been of interest for volcanology, geothermal development, etc. Magmatic intrusives have temperatures ranging from 700 to 850 degree C. Thus, there exists super-critical fluid around them. Numerical modeling of temperature changes around young volcanos and their heat sources thus requires treatment of the super-critical fluid. We describe one method for effective treatment of the super-critical fluid in the numerical modeling of porous media for the purpose of solving large-scale high-temperature problems of such phenomena. (author)

  18. Numerical method to calculate flow-induced vibration in turbulent flow. 3rd Report. Analysis of vortex-induced vibration in an array of elastically supported tubes; Ranryuba ni okeru ryutai kozotai rensei shindo kaiseki shuho no kaihatsu. 3. Kangun ni okeru uzu reiki shindo kaiseki

    Sadaoka, N.; Umegaki, K. [Hitachi, Ltd., Tokyo (Japan)


    A vortex-induced vibration of an array of elastically supported tubes is simulated in two-dimension by using a flow-induced vibration analysis program, which was developed in order to evaluate flow-induced vibration in various components such as heat exchangers. From a comparison of calculated results and experimental data, the following points are observed. (1) For the calculated results in a 5 {times} 5 square array, the flow pattern surrounding the first-row tubes is markedly different from that observed in the second-row or third-row tubes. This flow pattern is the same as that obtained from the experiment. (2) All tubes begin to oscillate due to unsteady fluid force and the oscillating mode is different for each row of tubes. These oscillation patterns show the same tendency in the experiments and it is concluded that the developed method can simulate vortex-induced vibration in an array of elastically supported tubes. 19 refs., 10 figs., 1 tab.

  19. Non-Newtonian fluid flow and heat transfer in a porous medium. 2nd Report. Prediction of porous inertia based on a three-dimensional numerical model; Takoshitsutainai no hi Newton ryutai no netsuryudo. 2. Sanjigen suchi model ni yoru takoshitsutai kansei koka no yosoku

    Inoue, M.; Nakayama, A. [Shizuoka University, Shizuoka (Japan). Faculty of Engineering


    Three-dimensional numerical calculations have been performed to simulate the viscous and porous inertia effects on the pressure drop in a non-Newtonian fluid flow through a porous medium. Cubes placed in an infinite space have been proposed as a three-dimensional model of microscopic porous structure. A full set of three-dimensional momentum equations is solved along with the continuity equation at a pore scale, so as to simulate a flow through an infinite number of obstacles arranged in a regular pattern. The microscopic numerical results, thus obtained, are processed to extract the macroscopic relationship between the pressure gradient-mass flow rate. Comparing the results based on the two- and three-dimensional models, it has been found that only the three-dimensional model can capture the porous inertia effects on the pressure drop correctly. 13 refs., 6 figs.

  20. Fiscal 1997 report on the results of the introductory R and D of the New Sunshine Project under a consignment from NEDO. Introductory R and D of the supercritical fluid use technology; 1997 nendo `New Sunshine keikaku` sendo kenkyu kaihatsu Shin Energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku. Chorinkai ryutai riyo gijutsu sendo kenkyu kaihatsu seika hokokusho



    The R and D of chemical reaction using supercritical fluids started in fiscal 1997. In the R and D of solvent reaction, as the research on polymer decomposition with supercritical water, studies were conducted of the mechanism of conversion reaction to chemical materials, cleavage mechanism of stable chemical bonds, and synthetic reaction in the supercritical state reaction field. In the research on oxidation reaction, as the study of complete oxidation in supercritical water for high efficiency energy recovery, studies of complete oxidation of liquid fuels, and complete oxidation of solid fuels. In the research on hydrogenation, studies of lightening of heavy oil in supercritical water, etc. In the R and D of the basic technology, studies of corrosion mechanism of metals in supercritical water, construction of the basic framework for technical database of supercritical fluids, etc. In the survey of technical trends and new research themes, the introductory R and D of element technology, etc. were conducted, and the results were described of the survey of technical trends and new research themes and the trend survey of overseas technology. 314 refs., 87 figs., 81 tabs.

  1. Fiscal 2000 achievement report on the venture business assisting type regional consortium - Minor business creation base type. Development of high pressure fluid aided dyeing and finishing system for cellulose textile products generating no waste liquid; 2000 nendo chiiki consortium kenkyu kaihatsu jigyo seika hokokusho. Cellulose kei sen'i seihin no koatsu ryutai ni yoru muhaieki senshoku kako system no kaihatsu



    There is a voice in the textile dyeing industry for a dyeing and finishing method without discharge of waste liquid from the viewpoint of environmental protection. When the special coexistence effect is applied to the technology of making polar dyes soluble in high pressure carbon dioxide, according to Associate Professor Mishima of Fukuoka University, a dyeing method is feasible wherein the separation of supercritical carbon dioxide and the dye is easier than in the conventional method of dyeing in water and wherein discharge of waste liquid after dyeing is not necessary. He also writes that technologies for recovering carbon dioxide have already been established. Under this project, attention is paid to cellulose textile products which will find a great demand, and efforts are made to commercialize a novel dyeing and finishing system of the low environmental impact type. The results of the research conducted under the project involve (1) the improvement of various dyes and assistants in their degree of solution in high pressure carbon dioxide, (2) development of a technology of attaching dyes and finishing agents to textiles, (3) designing and construction of a practical high pressure fluid dyeing and finishing apparatus, (4) search for optimum dyeing conditions for textile products using the said apparatus, and (5) the reinforced functions that textile products have after being dyed. (NEDO)

  2. Fiscal 1997 report on the results of the introductory R and D of the New Sunshine Project under a consignment from NEDO. Introductory R and D of the supercritical fluid use technology; 1997 nendo `New Sunshine keikaku` sendo kenkyu kaihatsu Shin Energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku. Chorinkai ryutai riyo gijutsu sendo kenkyu kaihatsu seika hokokusho



    The R and D of chemical reaction using supercritical fluids started in fiscal 1997. In the R and D of solvent reaction, as the research on polymer decomposition with supercritical water, studies were conducted of the mechanism of conversion reaction to chemical materials, cleavage mechanism of stable chemical bonds, and synthetic reaction in the supercritical state reaction field. In the research on oxidation reaction, as the study of complete oxidation in supercritical water for high efficiency energy recovery, studies of complete oxidation of liquid fuels, and complete oxidation of solid fuels. In the research on hydrogenation, studies of lightening of heavy oil in supercritical water, etc. In the R and D of the basic technology, studies of corrosion mechanism of metals in supercritical water, construction of the basic framework for technical database of supercritical fluids, etc. In the survey of technical trends and new research themes, the introductory R and D of element technology, etc. were conducted, and the results were described of the survey of technical trends and new research themes and the trend survey of overseas technology. 314 refs., 87 figs., 81 tabs.

  3. Numerical analysis of natural convection of thermoelectrically conducting fluids in a cubic cavity under a constant magnetic field. 3rd Report. Heat transfer enhancement effect, discrete del operator method; Jibaka ni okeru denjinetsu ryutai no rippotai cavity nai shizen tairyu kaiseki. 3. Jakujibaka no dennetsu sokushin koka, risanka nabura enzanshiho

    Nakai, T.; Tanahashi, T. [Keio University, Tokyo (Japan). Faculty of Science and Technology


    Generally speaking, the finite-element method in computational fluid dynamics is universally accepted, however computation by the CPU is time-consuming and requires large memory capacity for data storage. Therefore development of an analytical formulation to reduce the time and storage required for calculation is desired. In this paper, we propose a novel discrete del operator method in order to overcome these defects. This method is formulated using the discrete del operator as the element coefficient matrices in finite-element analysis, and low-memory and high-speed calculations are carried out. In particular, we examine whether this method is effective for the numerical analysis of natural convection of thermoelectrically conducting fluids in a cubic cavity. Moreover, we estimate the effect of heat transfer enhancement under a weak magnetic field on the Hartmann number. 13 refs., 5 figs., 6 tabs.

  4. Numerical analysis natural convection of thermo-electrically conducting fluids in a square cavity under a uniform magnetic field. 4th Report. Stable numerical scheme for low magnetic Reynolds numbers: scheme verification; GSMAC yugen yosoho ni yoru naibu hatsunetsu wo tomonau denji netsu ryutai no seihokei cavity nai shizen tairyu kaiseki. 4. Teijiki Reynolds su de anteina kaiho: scheme no kensho

    Oki, Y.; Tanahashi, T. [Keio University, Tokyo (Japan). Faculty of Science and Technology


    In the present paper, the natural convections of thermo-electrically conducting fluids in a square cavity under a uniform magnetic field are calculated using GSMAC-FEM in conjunction with the so-called B method. This scheme efficiently satisfies conservation laws of both mass and magnetic flux. In order to establish a stable numerical scheme at low magnetic Reynolds number problems, we introduce both the generalized trapezoidal method and the 3-level fully implicit method into the conventional numerical residual method. The numerical results obtained are in good agreement with the past numerical and experimental results. 13 refs., 7 figs., 2 tabs.

  5. Fundamental study on the new method to estimate vibration level on a ship. Formulation of the damping matrix based on dissipation energy caused by fluid viscosity; Senpaku no shindo level suitei ni kansuru kisoteki kenkyu. Ryutai no nensei ni yoru san`itsu energy ni motozuku gensui matrix no teishikika

    Funaki, T.; Hayashi, S. [Osaka University, Osaka (Japan). Faculty of engineering


    It is known in estimating vibration characteristics of a ship that fluid range affects largely a structure. In order to analyze the compound vibration therein, a method was proposed, which estimates vibration levels without using the finite element method. However, the problem of mode decay ratio has not been solved. Therefore, this paper first describes a method to introduce an equivalent linear decay matrix. The paper then mentions difference in the decay effects due to fluid viscosity in a shallow and deep water regions. Furthermore, vibration levels in the deep water region were estimated in a model experiment to verify the estimation result. Under a hypothesis that two-node vibration in a rotating ellipse has displacement distributions in the deep and shallow water regions equivalent, and when a case of vibration in a layer flow condition is calculated, dissipation energy in the shallow region is larger than that in the deep region by about 26%. About 5% of the total dissipation energy is consumed at bottom of the sea. According to a frequency response calculation, estimated values for the response levels still differ from experimental values, although the trend that the vibration levels change can be reproduced. 6 refs., 15 figs., 2 tabs.

  6. Numerical analysis on the deformation of free surface of magnetic fluid. 1st Report. In the case of steady non-uniform magnetic field; Jisei ryutai no jiyu kaimen no henkei ni kansuru suchi kaiseki. 1. Teijo hiichiyo jiba no baai

    Nam, W.; Watanabe, T. [Iwate University, Iwate (Japan)


    Numerical analysis is conducted on the deformation of the free surface of a magnetic fluid. Applied magnetic fields are steadily induced by a circular current loop located under the magnetic fluid. Governing equations of magnetic fields are solved using the concept of vector potential. Fluid flow is calculated by using the finite volume method with marker particles. The surface of the magnetic fluid is formed the balance of surface force, gravity, pressure difference, magnetic normal pressure and magnetic body force. The results of simulation show the instability of the free surface of the magnetic fluid due to the effect of the magnetic terms. The rise and fall pattern of the free surface of the magnetic fluid are qualitatively clarified, and the patterns of a steady nonuniform magnetic field induced by a circular current loop are quantitatively presented. 8 refs., 8 figs.

  7. Report of the results of the fiscal 1997 regional consortium R and D project. Regional consortium energy field / Development of an environmentally friendly industrial cleaning system using near-critical and supercritical carbon dioxide (first fiscal year); 1997 nendo chiiki consortium kenkyu kaihatsu jigyo. Chiiki consortium energy bun`ya / chorinkai ryutai wo mochiita kankyo chowagata kogyo senjo sochi no kaihatsu (daiichi nendo) seika hokokusho



    In the manufacturing process of semiconductors and in the high tech industry, cleaning is indispensable. At present, when regulation of the use of CFC which used to be much used has been decided on, the conversion to the use of substitutes for CFC cleaning is urgently needed. Transfer to cleaning by water/alcohol/hydrocarbon has been proceeded with, but there are a lot of problems. Out of the development of the cleaning method using supercritical fluid, the paper described the fiscal 1997 result. As to enhancement of efficiency and decrease in size of equipment, a cleaning experiment by high pressure CO2 around the critical point was conducted by integrating nozzle, ultrasonic generator and cavitation generator and adding solvent circulating system. Multi-purpose and energy saving of the equipment were also studied. To establish an analysis method for the cleaning degree, the contaminated component film of trace organic matter with a specified thickness was formed on the silicon wafer, and using the Fourier transform ultrared spectroscopy, a method to determine the film thickness was studied. For the function evaluation for precision machine parts and determination of optimum cleaning conditions, the cleaning/degreasing process of valves were compared with the conventional method. For the product manufacturing, the paper investigated and prepared the data in Japan and from abroad. 55 refs., 79 figs., 18 tabs.

  8. The International Space Station as a Research Laboratory: A View to 2010 and Beyond

    Uri, John J.; Sotomayor, Jorge L.


    Assembly of International Space Station (ISS) is expected to be complete in 2010, with operations planned to continue through at least 2016. As we move nearer to assembly complete, replanning activities by NASA and ISS International Partners have been completed and the final complement of research facilities on ISS is becoming more certain. This paper will review pans for facilities in the US On-orbit Segment of ISS, including contributions from International Partners, to provide a vision of the research capabilities that will be available starting in 2010. At present, in addition to research capabilities in the Russian segment, the United States Destiny research module houses nine research facilities or racks. These facilities include five multi-purpose EXPRESS racks, two Human Research Facility (HRF) racks, the Microgravity Science Glovebox (MSG), and the Minus Eighty-degree Laboratory Freezer for ISS (MELFI), enabling a wide range of exploration-related applied as well as basic research. In the coming years, additional racks will be launched to augment this robust capability: Combustion Integrated Rack (CIR), Fluids Integrated Rack (FIR), Window Observation Rack Facility (WORF), Microgravity Science Research Rack (MSRR), Muscle Atrophy Research Exercise System (MARES), additional EXPRESS racks and possibly a second MELFI. In addition, EXPRESS Logistics Carriers (ELC) will provide attach points for external payloads. The European Space Agency s Columbus module will contain five research racks and provide four external attach sites. The research racks are Biolab, European Physiology Module (EPM), Fluid Science Lab (FSL), European Drawer System (EDS) and European Transport Carrier (ETC). The Japanese Kibo elements will initially support three research racks, Ryutai for fluid science, Saibo for cell science, and Kobairo for materials research, as well as 10 attachment sites for external payloads. As we look ahead to assembly complete, these new facilities represent