We discuss future visualization. At first, we show a graphics pipeline. We redefine GPGPU as "Graphics-output Presupposition General Purpose Usage" and discuss graphics hardware future. We propose next generation visualization development environment concept "Visual Realityware". On "Visual Realityware", we are able to select best main stream technology any time and implement with minimum bug in shorter time. On visual communication, real time communication makes a support for our decision."MIERUKA (Visualization)" exposes issues. However we already have issues threre. "MISERUKA (Visionize)" means to share vision. Sharing vision prevents some issues. Image is important to share vision. Finally we show based on our experience that the high quality visualization is necessary for the collaboration with scientists, engineers and artists.
Optimizing the performance and increasing the comfort of high-speed trains require the knowledge of aerodynamic effects of a train shape. One of the most critical problems is a compression wave caused by a train entering a tunnel. This noise mainly depends on the cross-sectional area distribution of a train nose. On the other hand, the aerodynamic drag, the stability for side wind, and the low-frequency vibration are attributed to tail shapes. In this study, we studied the effects of train tail shapes on the flow field experimentally. Two models having the same cross-sectional area distribution but with different tail shapes were tested in a low-speed wind tunnel. To analysis the flow field around the model, we used pressure sensitive paint and oil flow techniques. As a result, we could identify the effects of tail shapes for pressure drag and cross wind stability.
The lifetime-based method has been applied to Pressure-Sensitive Paint (PSP) measurement in low-speed flow. Based on theoretical considerations and sample tests, a method to calculate pressure using "a-priori" method was proposed. In this method, pressure is related to the ratio of the luminescent intensity ratios obtained at two different gates between the wind-on and wind-off conditions, multiplied by a correction factor calculated from the single-point measurement of model substrate temperature. In order to evaluate the effectiveness of this method, a simplified car model was tested in a low-speed wind tunnel. It was shown that the effects of non-uniform distributions of lifetime and temperature could be cancelled out by the present method. The result obtained by the lifetime method was in good agreement with those of pressure taps and the intensity method.
LIF have been developed to measure the temperature, pH and the oxygen concentration in the fluid. However, the frequent excitation of the fluorescent dye causes the quenching effect. In addition, two color LIF should be applied in order to cancel the effect of non-uniform light intensity of excitation. The phosphor emitting the phosphorescence for a few milliseconds by an excitation was measured at the high time resolution, while the phosphorescence life time is the function of the temperature. As the phosphorescence dyes, PtT975 and PdT975 were tested. Those mixed with Coumarin30 were also demonstrated. These dyes were excited by a CW laser with the wavelength of 405nm. As a result, it was clarified to be able to measure the temperature using this laser and these dyes.
Phosphorescence and fluorescence are often applied to measure the temperature and the concentration of oxygen. The intensity and the lifetime of phosphor depend on the temperature and the oxygen concentration, due to the quenching effect of the phosphor. The present study clarified the effects of temperature on the lifetime of phosphorescence of Porphyrins, Ru(bpy)32+ and the europium complex. The phosphorescence lifetime of oil solution / water solution / painted wall were measured with changing temperature and oxygen concentration. In addition, the optical property of the small particles incorporated with the europium complex was investigated in the oil/water. The lifetime was strongly affected by temperature. Then, the temperature sensitive particle (TSParticle) with europium complex was applied to measure temperature in Silicone oil (10cSt) two-dimensionally.
The present study has been carried out with the aim of developing a technique for measuring two-dimensional gas temperature profiles based on two-color fluorescence induced by a one-color laser. The laser sheet of the fourth harmonic (266nm) from a Nd:YAG laser induced fluorescence of naphthalene doped in a nitrogen gas flow. The dependence of LIF intensity of naphthalene on temperature largely depends on wavelength. Thus, it is shown that the gas temperature is able to be determined by the ratio of LIF intensities at 320nm and 380nm.
The pressure-sensitive paint (PSP) technique has the potential as a diagnostic tool for measurement in the high Knudsen number regime because it works as a so-called "molecular sensor". However, application of the PSP technique to micro-systems is difficult because the conventional PSP is too thick owing to the use of polymer binder. We constructed pressure sensitive molecular film (PSMF), using Platinum(II) MesoporphyrinlX (PtMP), and have examined our PSMF to evaluate the possibility of application to the measurement of micro-flow. It is found that the pressure sensitivity of PtMP based PSMF is equal to the that of polymer PSP.
Pressure-Sensitive Paint (PSP) is applied to various wind tunnel tests as a useful technique to measure pressure distribution on model surfaces. PSP is inherently an absolute pressure sensor so that it is difficult to use this technique in low-speed flow where pressure change on a model is very small. To measure pressure with a high degree of accuracy at low speeds, we have developed a new type of PSP that responds to differential pressure rather than absolute pressure. This novel technique uses porous membrane through which gas containing no oxygen (e.g. nitrogen) is transported from the backside to the front side by pressure difference between the two. The transported gas purges oxygen near the surface and luminescence of PSP is enhanced. The results of sample tests show that the pressure sensitivity of the new PSP is higher than that of the current PSP by a factor of 100 times or more. In addition, the response of this sensor to differential pressure is almost linear and highly reproducible.
Bi-luminophore Pressure-Sensitive Paint (bi-PSP) has been developed in order to correct the error due to temperature dependence of PSP and increase PSP measurement accuracy. The bi-PSP was composed of pressure- and temperature-sensitive dye. Tetranuclear europium (III) complexes and PdTFPP were used as temperature- and pressure- sensitive dye, respectively. The luminescence intensity of the Eu complex was highly sensitive to temperature and insensitive to pressure. The bi-PSP was examined using a painted coupon and its characteristics were clarified. As a verification test, pressure distributions on a supersonic transport (SST) model at low-speed flow were acquired by the bi-PSP measurement system. The root mean square of Cp at 50m/s was approximately 0.1 (150 Pa) at flow speed of 50m/s, indicating that this bi-PSP system can measure more accurately pressure than conventional pressure conversion technique using reference PSP images immediately after stop of wind tunnel free stream.
In the present paper, current status of the development of luminophore-pendant temperature-sensitive paint of poly [1-(trimetylsilyl)phenyl-2-phenylacetylene] (PTMST) is discussed. PTMST uses poly(1-trimethylsilyl-1-propyne) (PTMSP) based polymer, which is known as one of the highest gas permeable polymer. We mix platinum tetrakis(pentafluorophenyl) porphyrin (PtTFPP) as a pressure-sensitive luminophore to create PTMST-based two-color PSP (PtTFPP-PTMST). We have calibrated PTSMT itself from 100K to 373K as well as PtTFPP-PTMST from 120K to 333K to study the static characteristics of these sensors. PTMST provides the temperature sensitivity over the calibrated range. PtTFPP-PTMST shows pressure sensitivity even at cryogenic temperature (120K). The unsteady characteristic of response time of PtTFPP-PTMST is determined to be on the order of milliseconds by using a shock tube. A demonstration of PTMST at cryogenic measurement is shown from transition detection on PTMST coated NACA64A012 model in JAXA 0.1m Transonic Cryogenic Wind Tunnel.
The photodegradation that occurs in the pressure-sensitive paint (PSP) is one of the serious error sources for pressure measurements using the PSP. The aim of the present experimental work is to study the effects of additives (phenolic antioxidant, sulfuric antioxidant and hindered amine light stabilizer) and annealing on the photodegradation of PSP. The changes in the luminescent intensity of the PSPs illuminated by an Hg-Xe lamp were measured under atmospheric pressure and room temperature. The present results show that 1) the phenolic and the sulfuric antioxidants promote the photodegradation of bathophenanthroline ruthenium(II) complex (Ru(Ph 2-phen)) dyes, 2) the sulfuric antioxidant improves the photodegradation of meso-tetra(pentafluorophenyl) porphine (H 2TFPP) dyes, 3) the annealing prevents the luminescent intensity of H 2TFPP-PSP from increasing after its initial decay.
We present a novel technique for rendering multiple volume datasets using particles as rendering primitives. In previous techniques, a data-intermixing process was required since the function is multi-valued. Although weighting values should be determined in this process, there are no specific guidelines for doing so. In contrast, our technique does not require data intermixing since we represent a volume dataset as a set of tiny, opaque particles which are generated with a stochastic technique. We applied our technique to volume datasets used for radiotherapy treatment planning in order to confirm its effectiveness.
Locating an optimal light source is an important task for image synthesis because it influences the spatial perception of the observers. Several methods have been proposed, that search for the optimal location of light sources for 3D surfaces, but none has been done for volumes. This paper presents a new method for finding an optimal location of a single parallel light source for volumetric ray-casting. The method computes the entropy of brightness distribution of representative isosurfaces. The method then utilizes the opacity transfer function to assign a distinct weight to each of the values of isosurface illumination entropy to evaluate the plausible illuminating entropy for the volume. The light with the maximum entropy value allows the observers to realize the volume features with enriched 3D visual cues.
When visualizing volume datasets, we frequently encounter a problem that optical occlusion makes it hard to grasp the spatial location (esp. depth) of target features precisely. A haptization is well-known as an effective solution to this problem. However, insufficient haptizations do not lead to a complete resolution, but also may give wrong information to users. It is important to design appropriate haptic transfer functions (HTFs) tailored specifically to a given dataset. Our primary focus in this study is placed on 3D diffusion tensors. Due to the developments of related scanning devices, the analysis of diffusion tensors has recently attracted much attention from related researchers. In this paper, we strive to present a 6DOF HTF, which utilizes 3D forces and 3D torques sophisticatedly to convey the core information of diffusion tensor values. The effectiveness of the 6DOF HTF using a PHANToM Premium 3.0 is proven through user evaluation experiments.
Reuse of previously created animation characters is very important for development of 3D animation movies and other contents. This report presents a technique for visualizing the animation data clustered based on their structures and motions. The technique uses "Heiankyo View" to visualize the hierarchical data storing the clustered animation data. It represents the animation data as four-frame cartoons by automatically selecting the four frames. The report discusses about the results of user tests of the four-frame cartoon generation.
Recent many information visualization techniques target complex data, such as time series and hierarchical data. The report presents a technique to additionally represent time series data by using HeiankyoView to visualize hierarchical data. The technique assumes the data consists of hundreds or thousands of hierarchical time-varying values. It divides a display space into square and thin spaces. The square space visualizes the hierarchy using HeiankyoView, and the other space visualizes the time-varying information.
A new network communication system was proposed for the online collaboration. The information visualization can aid to find and to predict an important sign from a huge amount of data. Data and eye views can be shared via internet by the developed system. The system promotes the online collaboration.
A new 3D visualization tool for a mobile-phone was developed and estimated in order to seek the possibility of 3D-view. The mobile phone was often used for searching certain facilities and stations, and for checking time-tables and so on. It needs to show so many information data, though the mobile phone has a very small display. Here, we applied the 3D-visualization technique for the software to search restaurants by the mobile phone. The software was verified by some users, as compared with 1D-visualization. It was clarified that the 3D-visualization has large advantage especially for unclear decisions.
Thinking processes and interest points are analyzed automatically from a track of mouse. Moreover, other scientific topics are introduced based on the analyzed interests. The track of mouse can be used also for detecting the indecision and the second best behind a final reply to a questionnaire. The visualized track of mouse gives us lots information about human cognition.
This paper reports a case study on the visual analysis for the development of a numerical computation algorithm. In order to accelerate the convergence speed of iterative numerical computation, the authors introduced a visual analysis of the convergence process into their algorithm design steps. In this visual analysis process, the authors discovered a phenomenon of the unnecessary divergence of residuals which may impede the speed of the convergence. Finally, this paper reports that their new algorithm which restricts the unnecessary divergence of residuals achieves reasonable acceleration of the performance for their surgical simulation.
Statistical analysis of the portable PC sales was accomplished using a structural equation modeling, a Monte Carlo simulation and a regression by neural network. The effect of the specification, the design, usability and the price on the sales of portable PC was examined based on the real market data which indicated the top 200 sales models over the fourteen week. From the present modeling method, the contribution of the price, the specification and the sensory items on the sales could be compared simultaneously. The product specification difference could be described as the price. A part of the product value of the portable PC could be visualized.
We propose an approach for categorizing data by assessing the degree of relevance among them manually. We employ a visual interface that allows moving the data around in the display screen, with which a person can arrange the positions of data so that the distance between them indicates the relevance as how one perceives it. As this interaction iterating, categories emerge where the data concentrate geometrically. In this paper, we report the evaluation of the approach by prototyping a system.
High speed and high resolution camera was installed to the Sclieren system to study thermal stratification flow. It is successful to obtain a clear Schlieren image which can be useful to observe moving thermal plumes in urban canopies. Pixel values of Schlieren image were converted to text data to examine the time change of brightness in urban canopies. The results show the fluctuations of brightness in urban canopies are extremely different from that above urban canopies.
In this study, wind pressure experiments were carried out and the effects of the roughness of the model wall surface and wind speed levels were examined. Furthermore, the wind flow fields around the models were measured using Dynamic Particle Image Velocimetry to examine the effects of roughness of the models and wind speed.
It is important to consider shallow water effect for design of ships, because there are several differences when the ship is sailing in shallow water and in deep water. Many studies have been done, however few experiments have been done because a special device is necessary to simulate the shallow water condition and visualize shallow water waves. In this study, a device for shallow water effect in a circulating water channel is developed. Experiments are carried out to study the performance of the device for shallow water effect. For these purposes, relationship between rotation of impeller and flow velocity and uniformity of flow velocity in the device should be investigated. Experimental visualizations of the shallow water wave using this device are carried out, and crest angles of the diverging wave are measured and discussed.
The turbulent flow over a wavy wall was visualized and quantitatively measured with a PIV. The flow in a channel with a flat top wall and a sinusoidal bottom wall were examined. The wave length and the amplitude of the wavy wall were 32 mm and 4.5 mm, respectively. The Reynolds numbers, defined with the half channel height, was varied from 500 to 3000. The flow separates from the wavy wall at the downstream of the crest and a recirculation region appears in the trough of the wavy wall. A large scale bursting motion out of the trough is observed for the higher Reynolds number case. The differences of velocity profiles depending on the Reynolds number are clarified.
Velocity fields of a spot vortex flow that happens spontaneously in the turbulent flow in a bubbling vessel are measured by using an improved defocus method. A new method is developed by improving the defocus method that can measure three-dimensional position of particles using a single camera. Performance of the new method is expanded in measurement range and in applicability to dense distribution of particles by introducing a color separation technique to the method. The spatial resolution of the method is less than 0.5mm in z-direction at the measurement distance of 380 mm.
The purpose of this investigation is to develop the flapping-wing micro air vehicles based on dragonflies. In order to reduce weight of mechanical flapper, MEMS technologies were introduced. An etching process was utilized for manufacturing the light weight wings. As a result, the weight of the mechanical flapper was 62 % lighter than that of the previous one. The flow fields around the mechanical flapper were almost the same as the dragonfly. The leading edge separation and wake capture process can be observed. The aerodynamic force of the mechanical flapper was proportional to the second powers of the flapping frequency. The experimental results showed that the flapping frequency for the flight should be required over 40 Hz at two pair of wings such as the dragonfly.
In order to clarify dynamic behaviors of a flying butterfly wings, the authors conducted flight observation experiments by a high-speed camera, measured displacements of a butterfly wings using images captured by the camera and transformed flapping angles from the butterfly's view into lead-lag angles. A butterfly moves its wings not only in upward and downward directions spatially but also anteroposteriorly when it flaps. For bound and towing flights, the butterfly changed flapping angles more greatly than lead-lag angles trying to escape from the towing since its legs and body were bound.
Pulsating jets are very common and sometimes useful in industrial fields, due to some differences in basic characteristics from steady jets. In this research, the authors focuse upon the frequency effect of pulsation on a circular jet. Experiments are conducted at a Reynolds number of 5, 000, Strouhal numbers of 0.13, 0.20 and 0.27, and a velocity-amplitude ratio of 0.5. Using olive-oil smoke, the authors visualise the flow near a nozzle exit, and get quantitative information by a PIV technique. Measurements on the entrainment flow rate give us another specific flow information, on which we discuss the frequency effect.
Concentration measurements of a high-speed unsteady gaseous jet were carried out using a Mie scattering method. Helium is injected through an automotive gaseous fuel injector into a pressure vessel. The injection pressure is set at 4.0 and 9.0 MPa(g), and the ambient pressure is varied from 0.1 to 1.0 MPa(a). The pressure vessel is filled with 1.2 μm-diameter scattering particles, and a pulse laser sheet is projected along the jet axis. Due to the displacement of the scattering particles, the Mie scattered light intensity decreases with the increase in the helium concentration. It is observed that the helium concentration along the jet axis decreases gradually with the downstream distance, and that it decreases rapidly near the jet tip. With the increase in the ambient pressure, the helium concentration inside the jet decreases. It is observed that the helium concentration in the jet has a self-similarity in the radial direction, which indicates that the intermittent gaseous jet can be treated as a steady jet except for the jet tip region.
In this study, 3-D unsteady viscous flow analysis around turbine blade cascade is carried out to investigate basic physical process involved in the pressure loss mechanism. In this regard, the strategy of the present study is first to compare the predicted results with the experimentally measurable data to check the prediction ability of numerical method. As a consequence of that the computed results agree with the experimental results. Therefore computed results could be used for visualization of the overall flow behavior to gather knowledge about what physical phenomena are associated with the mechanism of pressure loss. Because all the experimentally results compared so far with the computed results are the final outcome of the cause. From computed results, it turned that structure of vorticity from suction side and pressure side of turbine blade is a factor of pressure loss mechanism.
The impinging jet is widely used in the industrial field, as high heat transfer characteristics are obtained in the vicinity of a stagnation point on the object surface. In this paper, the heat transfer characteristics on the impinging wall after being blown off through a coaxial circular pipe were examined by changing the pipe-diameter ratio and the velocity ratio. As a result, the optimum values of the pipe-diameter ratio and the velocity ratio were found in the given conditions. The influence of the pipe-diameter ratio and the velocity ratio on the flow structure was clarified by the flow visualization.
A compound swirl jet which consists of an annular swirling jet and a coaxial free jet is effective as a push flow of the push-pull ventilator. In this paper, to enhance the mixing capability of the jet flow, the experiment was carried out under the condition of locating the inner tube of free jet to the upstream. The flow rate of the jet flow was examined for various nozzle depth by the measurement of velocity distribution. As a result, it was found that the optimum flow rate of the collection is obtained without the swirling flow, when the nozzle depth increases. The mechanism of the flow was clarified by the flow visualization using the smoke method.
In the pneumatic transportation, the authors propose that the effective and stable feeding of the particles can be attained by inserting the injection pipe at the center of the suction nozzle. In this paper, we examined the effect of extension length on the nozzle performance. As a result, it was found that the nozzle performance can be raised by extending the injection pipe. The various flow patterns particles obtained by different extension length were clarified by the flow visualization near the suction nozzle.
As a part of study on the jet control, the flow direction control of the jet was tried. The main jet issues from a circular pipe and the sub one from a half pipe placed on the side wall. The experiment of the direction control was conducted, changing the velocity difference between the main jet and the sub one. The flow visualization was carried out by the smoke method. As a result, it is clarified that the main jet was leaned toward the sub one, under the influence of the entrainment of the wall sub jet. Moreover, it is found that the direction control of the main jet is easy in the case that the velocity difference between the main jet and the sub one is large.
The present paper describes an experimental work to investigate a noise phenomenon in shock-containing jet from supersonic nozzle. When the nozzle runs at low nozzle pressure ratios, the shock wave occurs within the divergent section of the nozzle. The noise phenomenon of a jet flow is generated by an emission of strong acoustic tones due to the unsteadiness of the shock wave. A Schlieren optical system is used to visualize the flow fields of jet. Acoustic measurement is performed to obtain noise spectra. The results obtained show that unlike the frequency of the screech tone due to the shock-cell structures in the jet flow, the frequency of the acoustic tone due to the shock wave within the nozzle somewhat increases with an increase in the nozzle pressure ratio, and the acoustic tones take place in two stages.
Although the phenomena related to the multiphase flow can be found in many kinds of industrial and engineering applications, the physical mechanism of the multiphase flow has not been investigated in detail. The major reason for the lack of data in the multiphase flow lies in the difficulties in measuring the flow quantities of the multiple phases simultaneously. Presently, the simultaneous visualization and the PIV measurement have been carried out about the both phases of the liquid-liquid two-phase flow. The difference in the refractive indices makes the visualization in the vicinity of the boundary of the multiple phases almost impossible. In this study, the refractive index of the aqueous phase has been equalized to that of the oil phase by adjusting the concentration of aqueous solution. The PIV measurement has been carried out for the flow field around and inside of two falling droplets interacting each other while they travel.
Radial distributions of solid-water flows in a 9 mm-diameter pipe were measured by a stereo image-processing method and a hough transform method at normal- and micro-gravity conditions. The flow measurements were performed at an axial locations (axial distance from the inlet normalized by the pipe diameter=40) under various flow conditions of superficial liquid velocity (0.355-1.59 m/s). The effect of gravity on phase distribution patterns was discussed based on the obtained experimental data.
The volcanic eruption occurs due to the sudden decompression of the high-pressure high-temperature high-viscosity magma. It is mainly depended on the appearance of the gas phase in the magma whether it is an explosive eruption or not. In the present study, the volcanic eruption is reproduced with the high-pressure visible shock tube apparatus and simulant materials. The simulant materials for the magma are two-fluid component of silicone oil and acetone. In the experiment, the bubble forming behavior of the simulant materials and the rapid change in pressure is observed. Bubble forming behavior had completed in very short span and then bubbles developed. The number of bubbles nucleated under sudden decompression increased with the decompression rate. It is indicated from the experimental results that the driving force of bubble forming under sudden decompression depends on the decompression rate.
Longitudinal vortices sensitively govern the turbulent momentum transport in boundary layers. In order to obtain the fundamental knowledge on microbubble drag reduction mechanism, the interaction between the vortices and the bubbles are experimentally investigated in this study. The longitudinal vortex is generated artificially from a delta wing installed inside the shear layer in a channel. According to PTV measurement, the vorticity is reduced by presence of bubbles compared to the original. Significant displacement of the vortex core is also confirmed to explain the momentum transfer modification. Moreover, numerically simulated bubble trajectories on the measured velocity yields to high persistency of the interaction for small bubbles.
We have developed OpenGL Fusion technique which allows us to assemble two or more visualization results and CG models into a window without any modification to the original software. This paper describes the enhancement of the technique to support Cg and GLSL commands for high quality rendering. It makes the fusion of photo realistic CG and engineering CG.
Combination of visualization and the image-processing is a most suitable tool to provide high spatial-temporal interfacial data to develop two-phase flow modeling. Here the latest results of the data such void fraction, particle number density, and interfacial area concentration as in pipe flow are introduced, which obtained through visualization technique. The advantages and disadvantages of the technique are also discussed.
Cavitation bubbles are generated when the high-speed water jet is spouted into static fluid. The bubble collapse causes highly impact force. Therefore, the cavitating jet is applied to remove the dirty on the material and improve the fatigue strength of metallic materials, and so on. However, the cavitation exists only in the region near the center of the jet. In this study, the cavitating jet in the static fluid with bubbles is observed by taking photographs from the side and the front of the jet, and the erosion by the cavitating jet is examined. The results show that the capability for process is high on the center of the jet and around the jet for no bubbles, but the region of the high capability for process is wide and averaged when the bubbles are mixed in the static fluid.
A piston impact against a water column charged in a taper nozzle can produce a high-speed pulse water jet. In this paper, we analyze the high-speed pulse water jet with 500[m/s] class in the atmosphere, using CIP method. To verify the computational model, jet photograph by colored Schlieren method and moving pictures taken by high-speed video camera are compared with the numerical results. Consequently, collision and break up of jets as well as complicated shock waves around jet are comparatively simulated.
Recently, there has been an increase in demand for low-noise air conditioner. The reduction of noise generating from the expansion valve in an air-conditioner is particularly important. In order to design a low-noise operating valve, it is necessary to understand the flow characteristics of the refrigerant passing through the throttle of the valve. Therefore, we manufactured an expansion valve with a new throttle design. We compared the performances of the original and new throttle design by monitoring the refrigerant flow conditions and the acoustic noise generation. As results, it was confirmed that refrigerants flow of the upstream of throttle influences in predominance. The reduction in the noise power spectra in the high frequency domain has been made, which is the one that poses particular problems for the human ear.