Hydraulic model test was conducted to study the effect of Isahaya Dyke on the oceanic current in Ariake Bay. Tidal current was visualised by PIV. We found that the dyke changes the residual current in and near Isahaya Inlet very much. This may imply lower rate of water exchange in the inlet than that in the past and, eventually, possible occurrence of red tide that devastated Nori crop near the inlet. Also observed was the distribution of dye injected in the bay. The dye imitates the emitted water, which sucked from the deep layer by an apparatus called the Density Current Generator (DCG). The DCG is expected to improve the water quality under the strong stratification in summer.
During quenching process, steam film and boiling bubbles occurring on the boundary layer between quenching steel and quenchant often lead to uneven heat transfer and in turn distortion and heterogonous microstructure in quenching steel. In this paper, experiments of stirring quenching to induce forced conventional flow and to break boiling film are carried out. The formation and movement of boiling bubbles and forced convectional flow are investigated with a high speed camera. Visualization of boiling bubbles and forced flow are performed by PIV-PTV methods. Furthermore, cooling curves of a steel cylinder during quenching are measured and the heat transfer coefficient between quenchant and steel is identified. Finite element simulation is performed to analyze the flow effect on heat transfer. By combining analysis of visualized flow from measurement and simulation, the behaviors of steam film and forced flow are clarified and improvement on heat transfer by stirring is confirmed.
A cold moderator using liquid hydrogen is one of the key components in a MW-scale spallation target system, which is cooled down by using a impinging jet flow. Flow visualization experi-ments with a simulated moderator vessel with cylindrical configuration were carried out in order to clarify flow patterns in the cold moderator vessel, which showed jet induced flows such as recirculation flows and stagnant regions. Analytical results of velocity distributions ob-tained with the standard k-s turbulent model agreed well with experimental results obtained under the bight and diameter ratio (h/D) of 2.0. However, analytical turbulent energy and heat transfer coefficients of a bottom of the vessel could not predict experimental values well.
To clarify the effect of the aspect ratio on the pulsating flow through the rectangular channel the pulsating flow with a reciprocated 50Hz fluctuation has been investigated experimentally. The experiment was carried out with two different aspect ratios (α??1, 8.33) and the technique of PIV with the recursive direct cross-correlation was used to accomplish velocity field measurements. The PIV measurement was synchronized with the AC power supply to the pulse pump and the phase averaged velocity profiles were measured at 10°phase angle intervals. The experimental results revealed that the ensemble averaged axial velocity profile changes from the parabolic profile to the flat one according to increase of the aspect ratio from 1 to 8.33. It was found that the phase averaged axial velocity profile changes with the phase angle and the inflection points due to the friction of the channel wall appear near the wall in those profiles.
A water storage tank is proposed to be used at the heavy damage of water supply line of a city. Though, it is a part of pipeline and is expecting that the fresh water flows normally and works as the storage tank for the drinking water at the emergency due to the earthquake. As water is used for drinking, it is not expecting to have a dead water stagnation zone in the tank. In this study we made a one fifth scale transparent model of the water storage tank. It was used for the experiments by the dye injection method, PIV and compared with numerical simulations. The experiments were made using three types of inlet nozzles with different lengths and angles. The injected dye flow was recorded by video camera and PIV measurement was also made in several cases. And numerical simulation of flows was made for the model tank with the same condition of experiments. From the results of experiments we have demonstrated that controlling inlet nozzle makes no part of stagnation area.
It is said that the so-called Oloid wing would enable to stir the fluid effectively with less energy. However the detail of its phenomenon is not clarified yet, particularly the comparison of the Oloid and the conventional propeller-type stirring device has not been done. This paper deals with the flow visualization around the Oloid wing and the propeller type machine. For the visualization of the flow, the micro bubble method is employed here and one of the PIV method is used for the analysis of digital recorded images, not for the velocity measurement but for the analysis of the visualization images. It is observed that the flow caused by the propeller is concentrated and meandered near the centerline of the machine, while the flow of the Oloid shows strong unsteadiness in wide region.
An integrated micro wind turbine system has been developed and investigated on the flow around the turbines. The system is available for the usage on the top of the building, wind breaking on the boundary of our environment, etc. In the present paper, a 1/10 scale model of the system was explored with a wind tunnel facility. The purpose of the scale test is to investigate the wake flow of the system and optimize the configuration of its integration. In the present experiment, a basic array is assumed as 5x5 units and it was placed in the boundary layer in the test tunnel. The approaching flow and the wake were measured by using a hot wire anemometer and particle image velocimetry. The velocity profile and the turbulence behind the system were examined in detail.
A new quantitative technique for measuring the internal flow of fuel injection nozzles was developed. This technique is characterized by the use of transparent models enlarged seven times, and application of the refractive index matching method using Turpentine-Tetraline mixing oil and the fluorescence PIV that can eliminate the light scattered from gas-liquid border surface. This technique enables the measurement of velocity flow field in the sac chamber and nozzle holes. And, we report one analyzing result applied the multi-hole nozzle by using this method.
Hemodynamics plays very important roles on development and growth of intracranial aneurysms, abdominal aortic aneurysms and carotid stenoses. However, there is no well-established in vivo or in vitro hemodynamics measuring system in human vessels at present. Therefore, we established an in vitro simulator for measuring and visualizing hemodynamics in human vessels, characterized by the following items, 1) obtaining multiple 2-dimensional slices including human vessels with the use of a clinical imaging scanner; 2) calculation of 3 dimensional vessel data sets by a computer based on previous clinical data sets; 3) production of a realistic hollow silicon vessel model using previous computer data sets and a three-dimensional printing using powders and adhesive; 4) completion of refraction index matching between the silicon model and a mixture of glycerol and distilled water ; 5) whole field measurement of hemodynamics in the model by using particle image velocimetry. This simulator enabled us to obtain tailor-made hemodynamics in patients' pathological vessels which were as realistic as possible.
The propulsive performance of fish-like motion was analyzed by estimating the thrust and drag forces at self-propulsive point. Numerical simulations and experiments were carried out for the analysis, and it enables us to know the hydro-dynamical propulsion performance of fish-like motion. The two-dimensional waving wing was employed for the target of basic study of propulsive performance, and the hydrodynamic forces acting on the wing were investigated.
The genetic algorithm was already applied with success to the particle pairing process of the 3-D stereoscopic particle tracking velocimetry by the present author. In the present study, the algorithm has been further improved for more accuracy of particle pairing and reduced computation time. The point of the improved algorithm is a new-concept genetic encoding scheme, according to which the gene strings of each individual do not start from globally random sets of particle ID's but from pre-selected candidate pairs of ID's. The crossover and mutation schemes are likewise modified from conventional methods in order to meet with this new strategy. Thanks to the pre-selection of candidate pairing particles, the algorithm converges more quickly and the number of erroneous pairs is reduced.
This paper presents a new observation system for digital holography in which the position of the particles distributed in 3D space can be detected with high accuracy. In the present system, two different hologram patterns, generated with two expanded laser lights orthogonally intersecting, are simultaneously recorded on a CCD sensor to convert them to one digital image. The position of small particles in 3D space is measured by identifying each particle between the numerically reconstructed images of particle in near range and those in far range. The particle identification is carried out in the relative space coordinates the origin of which is set using a thin needle. The test results for the particles attached to a glass plate show the higher measurement accuracy of the present system based on digital holography than the conventional one.
Standard PIV system using double-pulse laser and double frame camera with high resolution is used to be applied to for high-speed flow. Nowadays PIV system (high-speed camera and high-power laser with high repetition pulse) with lkxlk pixels in image size and 2kHz in frame rate is available. This system is called as "Dynamic PIV', and the dynamic range for time and space are expanded 1 to 2000 and 1 to 100, respectively In this paper, we describe a system to expand the dynamic range for space and it is applied to free jet.
Presently, a new calibration scheme for the camera under the Scheimpflug condition is proposed, which represents an exact projection from the object through the lens to the inclined image sensors and also handles the distortion by the lens theoretically. By this scheme, a highly precise three-dimensional calibration can be carried out and thus the accurate three-dimensional projection, which is inevitable for the development of three-dimensional three-component 3D3C PIV, can be calculated. Preliminary tests show that the present scheme gives better projections than the normal projection scheme and much better results than the conventional two-dimensional third-order polynomial fit.
Water bell which resulted from the equilibrium between surface tension and centrifugal acceleration was found by Felix Savart in 1833 for the first time. To investigate the effects of surfactant on water bell formation, we took photographs of the water bells both of distilled water and surfactant including water with high-speed video camera. Then, we analyzed them. From these, it was found that the surface area of the water bell at same jet velocity became small when the surfactant was added and the surface shape at same jet velocity became very stable when the surfactant was added.
In order to atomize a liquid, the authors have investigated the behavior of air- water jets. In a series of experiments, we have discovered a strange phenomenon that the water jet accompanied with an air suction from the free surface has made a periodic radial splash of water drop. The purpose of the present paper is to clear out the origin of this phenomenon by flow visualization. The dynamic behavior of this phenomenon has been photographed by a digital camera aided with a flash light and high-speed video camera. Those experiments enable us to find the origin of such phenomena due to a formation of a single air bubble at the flow separation region inside the nozzle and due to explosive expansion of the bubble after injected in the free space.
The impulsive pressure wave radiated from a tunnel exit (micro-pressure wave) is one of the most important environmental problems of high-speed railways. For solving the problems of micro-pressure waves, the unsteady flow induced by a train entering a tunnel needs to be clarified because the micro-pressure wave is radiated at the arrival of the compression wave generated by the train entry. In this study, we conduct a 1/127 scale model experiment and investigate the unsteady flow induced by the train entering the tunnel by applying the flow visualization technique to use oil mist and a high-speed camera. The results reveal that a jet flow is emitted from the entrance and a vortex ring is generated and collapses thereafter. Furthermore, a jet flow from a window at the tunnel side wall is also observed.
To make clear the principle of a breaking pitching of baseball, we have developed a image processing system of pitching ball. This system can detect a rotation speed and a direction of rotation axis of ball from images taken by a high-speed video camera. These images were taken at frame rate of 500 or 1000fps and shutter speed of 1/2000 or 1/5000s. The velocity of ball was determined by its position in 6 continuous flames. The rotation speed and axis of rotation were determined from the pattern of seam. The pitching balls of test pitchers were analyzed by the present system, and discussed. The present system will be used in an analysis of the pitching ball, a training of pitcher, a development of new breaking pitching and so on.
To evaluate the effect of the bullet impact on the human body, we tried to visualize the deformation and its velocity in the quasi-transparent ballistic gelatin. We made the ballistic gelatin with tracers, which were made of wool yarn. By using this ballistic gelatin with tracers and high speed camera, we could measure the degree of deformation and its propagating velocity, dynamically.
Bubble behaviors in liquid have been studied in many engineering fields relating to a power plant, chemical reactor, mixing system, and so on. In those systems, Bubble shapes, motions and surface areas are the most important subjects in order to pursue transport phenomena and to estimate mixing performance. When gases are blown into liquid, bubbles are formed. Once this procedure is observed through high-speed camera, they exhibit anomalous transient shapes and behaviors are found. Similar bubble-shapes had been found in the cavitation, which occurs quite different circumstances from the present case. In this paper, a variety of bubble shapes and behaviors are shown but transient procedures how those features are continuously changing. The transient phenomena play an important role in many gas-liquid two-phase systems, since during the transient period, bubbles are exposed to rushing flow and bubbles cause turbulent flow.
Using high-speed camera, we have been doing some experiments to clarify the mechanism of the commutation spark generation from the image aspect in universal motor. Previously we mentioned about the cases of single and plural number of sparks generation at single commutator segment This time, we took pictures of all the sparks generated during a single-rotation of the motor and examined sparks generation distribution and their positions of the brush. As a result, we observed that the closer the position to the side where the brush and the armature coil are connected the more sparks are generated. Also we measured the voltage between brush and commutator segment.
It is known that manipulators of marine robots are oscillated by Karman-vortex shed from themselves when move in a water. To prevent them from oscillations, it is necessary to grasp the flow pattern around manipulators and to make clear relation between the flow and the fluid forces. Therefore, authors researched into flow around a circular cylinder turned round its end in a fluid. In this report, when the test cylinder elastically supported was swinging, the flow was visualized and the relation between vortex shedding and oscillation of cylinder were investigated. The characteristics of flow around a elastically supported cylinder was distinguished from a rigidly supported one.
The discrete frequency noise is generated from an airfoil in a uniform flow at small angle of attack to the free stream at moderate Reynolds number. The present experiment is conducted to find the reduction condition of discrete frequency noise by the influence of cylinder wake using a surface-flow visualization technique by shear-stress sensitive liquid crystal coating. Utilizing the color image analysis, the point of flow separation and reattachment is evaluated from the visualized images. It is found that the region of flow separation over the airfoil was fairly reduced by the influence of cylinder wake, where the suppression of discrete frequency noise was observed. The laminar boundary-layers over the airfoil seems to be shifted to a turbulent state by the influence of cylinder wake.
In the previous measurement of the aerodynamic sound generated from an inclined circular cylinder, it was found that the sound pressure level (SPL) changes with the aspect ratios and the inclined angles. Thus, in this study, we have investigated the changes in the vortex structure of the wake considered as one of the causes of the SPL variation. Using the low-noise wind tunnel, we measured the velocity fluctuation of the wake to obtain correlation length. Moreover, the flow visualization tests are performed with a hydrogen bubble method and a numerical analysis method in order to clarify how the wake changes by variation of the inclined angles and the aspect ratios. As a result of this investigation, it was found that the spanwise structure of Karman's vortex street was broken down by the upward flows generated around the bottom endplate and the degree is smaller as the aspect ratio is larger.
The characteristics of turbulent structure in turbulent open channel flow with longitudinal ridge elements were investigated by using flow visualization techniques. The velocity measurements show that the mean primary flow velocity over ridges was low and their turbulence intensities were high, and relatively the mean primary flow velocity over troughs was high and their turbulence intensities were low. The results of flow visualization suggest that vortical structures formed on ridge elements and troughs contribute to the generation of characteristics of velocity distributions.
Many researchers of both domestic and oversea promote the report in relation to the liquid ring pump. However, there exist only few reports that are discussed about the visualization of the liquid ring between the liquid as the working fluid and pressured gas at present. What is worse, the content of such current discussed report of the visualization of the liquid ring is only visualized the cross sectional images of the inside of the liquid ring pump by taking a photograph or other media. Therefore, our report "The Visualization of Liquid Ring inside a Liquid Ring Pump" treats this research theme by visualizing and discussing the visualization of the liquid ring between the liquid as the working fluid and pressured gas systematically, and figures out the characteristics of the liquid ring pump under various conditions for more meaningful development of it.
The field of microfluidics is developing rapidly with advances in MEMS and μTAS technologies. In various devices, it is required to control the flow rate of liquid or gas accurately at micro or nano liter volume. In T-shaped micro channel with a rectangular cross section, the liquid-gas two-phase flow was observed. To investigate the interfacial behavior of liquid-gas flow, the T-junction and the outlet were visualized using a high-speed CCD camera attached to a microscope system. From visualization study, the deformation of the interface and period of the breakage were observed. Though the mechanism of breakage was deterministic, the period of breakage was not periodic. This instability is considered to be caused by huge expansion at the outlet. Since the mechanism of breakage is stable, the possibility of the controlling flow rate was suggested.
Effect of porous metal immersed in cylindrical capsules on melting of solid phase by forced convection was studied by flow visualization technique. Experiment was compared with numerical analysis. Melting characteristics without porous metal agreed with the numerical results based on the non-uniform heat transfer coefficient on the capsule surface. Porous metal inserted in the capsules reduces the surface temperature of the capsules and suppresses natural convection. Finally, increase in effective thermal conductivity due to porous metal reduces melting time of the phase change fluid. The shape of the solid liquid boundary became more concentric by inserting the porous metal.
In our laboratory, effect of Ar + laser irradiation on the activity of frog sciatic nerve, especially thecompound action potential(CAP)and the law of polar excitation, were investigated. During the laserkmadiation(Continuous Wave, 514mm, 50mW), CAP showed a significant decrease in amplitude. Theattenuation speed in CAP amplitudes of anode break excitation (AE) was clearly larger than that ofcathode circuit-closed excitation (CE) on the law of polar excitation. It is reported by some papers thatattenuation in CAP amplitude is based on the influence of the heat generated by laser irradiation. In this study, heat changes of the nerve specimen surface and inside were measured usingthermography and thermocouple in order to consider the heat influence on the nerve activity by laserirradiation.
The device measuring micro-nano bubbles whose diameters were from 1 to 10 micrometer was developed. The bubbles were visualized by a close-up photographing and image processing system with high magnification microscope. The floating velocity of the bubbles as a physical characteristic was measured by using the system. The velocity of micro-nano bubbles does not depend on Stokes' law. The micro-nano bubbles were observed in not only tap water, but also distilled water and seawater.
Generating mechanism of micro bubble and its physiological characteristics of scallop was investigated. Micro bubbles were generated by the formation of rotating two phases fluid in the device. The rotating velocity at the exit of the generating device was about 400 revolutions per second. A reaction of scallop with large open of the mouse provided with the bubbles was observed in seawater. Further, the blood flow of the scallop provided with micro bubbles increased about two times higher before the provide.
The use of laser-induced fluorescence (LIF) from acetone is becoming increasingly widespread as a flow diagnostic, however, limited to measurement of low speed flowfields. In this paper, acetone planar laser-induced fluorescence (PLIF) is applied to measure the flowfield of under-expanded supersonic freejets. The field of number density taken by the present method is compared with the theoretical one obtained by CFD method. As a result, it is found that this method may be the powerful tool for measuring the density in supersonic flowfields.
Color visualization of engine combustion has been a tough task for digital processing devices because of its severe requirement in resolution and processing speed. C-MOS camera has become a promising substitute for high-speed film camera for that purpose. In this study, a newly introduced C-MOS camera was tested to check its potential as a high-speed photographing device. Furthermore, flame temperature measurement on the two-color method is attempted in order to evaluate its color fidelity and to clarify the difference in analysis procedures. All in all, measurement results showed its strong potentialities for high-speed visualization in spite of the restriction of color resolution.
The interaction between molecular transport and the three-dimensional flow field in microfluidic devices is investigated by an improved micro-LIF (laser-induced fluorescence) technique refined for use at microscopic spatial resolution. The pH distributions of chemically reacting flow at a Y-junction in a neutralization reaction between strong acid and strong base in a microchip, were visualized with 0.0032 pH/intensity and a spatial resolution of 0.89×0.89μm. To access the three-dimensional flow field, the pH distributions at three kinds of depth (top, middle, bottom) were investigated. The microscope has a working distance resolution of 1 μm in depth, and the depth of field of the system was 0.53 μm. In any depth, proton transports seven times faster than the theoretical prediction.
Investigation into CO2 dissolution behavior into water is very important in any strategy of CO2 sequestration. We tried to measure the pH distribution around a dissolving CO2 droplet in a high pressure vessel by using 2 color Laser Induced Fluorescence method, in order to cancel a fluctuation of laser light intensity. As fluorescence dyes, quinine and sulforhodamine were used. Molar absorption coefficient and emission intensity of quinine depends on pH of aqueous solution, while those of sulforhodamine are not affected by pH. The ratio of these fluorescence intensities represents pH at each point of image. Two dimensional pH distribution around dissolving liquid CO2 droplet under high pressure condition, 10MPa, give also a 2-D map of CO2 concentration.
This paper describes an uncertainty analysis of simultaneous measurement of temperature and three- components of velocity by stereoscopic liquid-crystal thermometry and velocimetry using thermo-sensitive liquid-crystal particles and tracer particles. The uncertainty analysis of the measurement is carried out with the artificial stereo-color-images, which are generated from the numerical simulation data of thermal convection in combination with the experimental color characteristics of liquid crystals at various viewing angles. The results lead to the optimum stereo viewing angles for the measurement of temperature and velocity with high accuracy. It is also suggested that the accuracy of measurement can be improved by optimizing the number of particles, the pixel diameter of tracers and the intensity of the tracer particles.
In this paper, we report an experimental technique for simultaneous measurement of temperature and three-components of velocity in three-dimensional thermal flow using scanning liquid-crystal thermometry and stereoscopic PIV. The three-dimensional measurement is carried out by scanning the light-sheet plane while capturing the sequential color images of liquid crystals and tracer particles. The present experimental technique is applied to the turbulent convection and the three-dimensional structures of thermal plumes are studied. The experimental results indicate that the structures of plumes are sometimes correlated with the vertical velocity of the fluid, but they behave randomly in space influenced by the large-scale turbulence.
As an electric device is miniaturized in recent year, the object of temperature measurement also becomes very small. Although it is already known that the temperature measurement method by liquid crystal is effective in measurement of a thermal field, a small thermal field cannot be measured by the conventional measurement method. Therefore, in this study temperature measurement and visualization are enabled in a small area of natural convective field by expanding thermal and flow field and by taking these pictures. Moreover, even when a heating element is reflected in a picture, we propose a new temperature measurement method by liquid crystal. As a result, in a small area of natural convective field we enabled measurement of a small thermal boundary layer.
In this paper, turbulence characteristics of boundary layer flow over a heated punching board have been analyzed. Two kinds of heated board, which are a smooth board and a punching board, are tested in a vertical wind tunnel. The diameter of holes is 20mm with staggered arrangement in a punching board and the boards are 10mm in thickness. These studies are made by means of PIV (Particle Image Velocimetry). The mean flow velocity is 4.5 m/s and the relative turbulence intensity is 1.5 %.Comparisons of the mean velocity and turbulence intensity are made for the smooth and punching boards under heated or non-heated conditions.
Under certain conditions, supersonic jet issuing from a supersonic nozzle invariably generates supersonic jet noise, which consists of three principal components ; the turbulent mixing noise, the broadband shock-associated noise, and the screech tones. In present study, it was experimentally investigated to the effect of nozzle lip thickness on the characteristics of supersonic jet noise. The convergent-divergent nozzle of design Mach number 2.0 was used in experiment. With two different cases in the nozzle-lip thickness, pressure ratio was varied in the range between 2.0 and 12.0. Acoustic measurements were conducted by microphones in an anechoic room, and the major structures of the supersonic jets were visualized by a Schlieren optical system for the purpose of the effect of nozzle lip thickness. The measured results show that the characteristics of supersonic jet noise, such as overall sound pressure level and screech frequency, depend upon the thickness of nozzle lip.
Recently, Mach reflection, which has long been considered to be a self similar phenomenon, turned out to exhibit non-self-similar characteristics by a series of detailed experiments with optical visualization technique. On the other hand, it is inferred by a numerical experiment, that the effect of transport properties (viscosity and thermal conductivity) on the solid boundary is the physical cause for such a non-self-similar and thus unsteady phenomenon. Usually, the solid boundary has surface roughness to some extent. In the present paper, we have investigated the effect of surface roughness on the dynamic transition, which occurs during shock propagation, and the behavior of wave angles.
In order to quantitatively observe spherical shock waves and the flow field behind them, an aspheric spherical transparent test section was designed and constructed. Spherical diverging shock waves were produced at the center of the spherical test section by irradiation of a pulsed Nd:YAG laser beam on micro explosives. Pressure histories at different points over the test section were measured to validate production of uniform shock waves. After reflection of spherical shock wave from the test section, a converging spherical shock wave was produced. Double exposure holographic interferometry and time resolved high speed photography were used for flow visualization. The whole sequence of diverging and converging spherical shock waves propagation and their interaction with product gases were studied.
A numerical investigation was performed on the three-dimensional flows and vortices within the flow separation in a decelerating channel flow in order to make clear the vortex behavior according to the profiles of the inlet velocity in detail. At first, the availability of our simulation was discussed in comparison with the experimental data by Kinoue et al.. Then, the vortex visualization by using the computational results was carried out. The visualization technique is based on the positive value of the second invariant for the velocity gradient tensor mapping the normalized helicity. As the results of our investigation, the availability of our simulation was confirmed and the vortex behavior depending on difference in the inlet velocity profile was shown.
Flow visualization in a target for the accelerator driven system was analyzed numerically to obtain the fundamental flow characteristics under annular channel geometry with a reverse section. The analytical geometry simply simulates the experimental condition. The three-dimensional numerical computations were carried out using the SCRYU/Tetra code and the nonlinear low Reynolds turbulence model. Two kinds of channel end geometries were provided as a numerical parameter. From the present numerical study, the following conclusions were derived: an effect of the channel end geometry to the fluid flow behavior was clarified; and, detailed flow configurations inside the annular channel with a reverse section were predicted quantitatively.
In today's CFD-assisted turbomachinery design, a primary objective is to minimize the effects of vortices. Their automatic identification, along with other flow structures, in numerical data is a current research topic. This paper presents a novel method to find vortex hulls in turbomachinery flows automatically. Based on a vortex core line that is the centerline of the vortex, the method is able to locate bent vortices and to distinguish adjacent vortices in the complex flows. We experiment with the method on several practical flow data sets from the field of turbomachinery.
Thermal-hydraulic safety in a tight-lattice bundle has been analyzed to contribute thermal design of an advanced water-cooled reactor core. Since the analytical geometry is complicated, it is difficult to understand the analysis results using general visualization software. In this study, the visualization program for the thermal-hydraulic analysis in the tight-lattice bundle was developed using the software AVS/Express. It can reproduce the three-dimentional view and graphs of the analysis results and it is helpful in understanding the thermal-hydraulic phenomena in the tight-lattice bundle.
We developed the real-time visualization system combined with solver of lattice Boltzmann method (LBM), which is efficient algorithm for simulating binary-fluid flow. Developed System enables us to visualize the result solved by LBM in real time, capture the interface moving we want to see in detail, and save the cost of computer resource for visualization In this article, we present the simulation of phase separation as an analytical example by using LBM Real-time Visualization System.
A visual-oriented numerical method which applies the spreadsheet of Excel has been proposed. In the present study, a programming process on two-dimensional unsteadystate heat conduction problem in cylindrical coordinate system is explained by way of a specific example, where a short round bar is put under sudden heating on its end and is cooled by forced convection around its side surface. The present unsteady-state numerical calculation has been realized by introducing one to one correspondence of each time to each sheet. Through calculations on sudden heating of a round bar model, the proposed method is shown one of useful numerical methods.