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Kaushal D.R.,Indian Institute of Technology Delhi | Kumar A.,YMCA UST | Tomita Y.,Kyushu Institute of Technology | Kuchii S.,Kitakyushu National College of Technology | Tsukamoto H.,Kitakyushu National College of Technology
International Journal of Multiphase Flow | Year: 2013

Pipeline slurry flow of mono-dispersed particles through horizontal bend is numerically simulated by implementing Eulerian two-phase model in FLUENT software. A hexagonal shape and Cooper type non-uniform three-dimensional grid is chosen to discretize the entire computational domain, and a control volume finite difference method is used to solve the governing equations. The modeling results are compared with the experimental data collected in 53.0. mm diameter horizontal bend with radius of 148.4. mm for concentration profiles and pressure drops. Experiments are performed on narrow-sized silica sand with mean diameter of 450 μm and for flow velocity up to 3.56. m/s (namely, 1.78, 2.67 and 3.56. m/s) and four efflux concentrations up to 16.28% (namely, 0%, 3.94%, 8.82% and 16.28%) by volume for each velocity. Eulerian model gives fairly accurate predictions for both the pressure drop and concentration profiles at all efflux concentrations and flow velocities. © 2013 Elsevier Ltd.


Kaushal D.R.,Indian Institute of Technology Delhi | Thinglas T.,Indian Institute of Technology Delhi | Tomita Y.,Kyushu Institute of Technology | Kuchii S.,Kitakyushu National College of Technology | Tsukamoto H.,Kitakyushu National College of Technology
International Journal of Multiphase Flow | Year: 2012

Pipeline slurry flow of mono-dispersed fine particles at high concentration is numerically simulated using Mixture and Eulerian two-phase models. Both the models are part of the CFD software package FLUENT. A hexagonal shape and cooper type non-uniform three-dimensional grid is chosen to discretize the entire computational domain, and a control volume finite difference method was used to solve the governing equations. The modeling results are compared with the authors' experimental data collected in 54.9. mm diameter horizontal pipe for concentration profiles at central vertical plane using γ-ray densitometer and pressure drop along the pipeline using differential pressure transducers. Experiments are performed on glass beads with mean diameter of 125. μm for flow velocity up to 5. m/s and four overall concentrations up to 50% (namely, 0%, 30%, 40% and 50%) by volume for each velocity. The modeling results by both the models for pressure drop in the flow of water are found to be in good agreement with experimental data. For flow of slurry, Mixture model fails to predict pressure drops correctly. The amount of error increases rapidly with the slurry concentration. However, Eulerian model gives fairly accurate predictions for both the pressure drop and concentration profiles at all efflux concentrations and flow velocities. Velocity and slip-velocity distributions, that have never been measured experimentally at such higher concentrations, predicted by Eulerian model are presented for the concentration and velocity ranges covered in this study. Slip velocity between fluid and solids dragged most of the particles in the central core of pipeline, resulting point of maximum concentration to occur away from the pipe bottom. © 2012 Elsevier Ltd.


Yamamoto Y.,Kitakyushu National College of Technology | Tachibana T.,Kyushu Institute of Technology
Fuel | Year: 2016

Plasma-assisted combustion can be used to achieve combustion of fuels that are difficult to utilize, which can help in combating the current energy and environmental problems. However, current plasma-assisted combustion technologies employ oxygen, which is proficient in reactivity but heavily degrades electrical contacts over time. Therefore, we propose the use of water, which is readily available, low cost, and ecofriendly, as feedstock of plasma jets (PJs), by examining the usefulness of water PJs for combustion promotion. Combustion tests for methane (CH4)/air mixtures were conducted using our original experiment apparatus with three types of PJ feedstocks, i.e., Ar seeded with O2, N2, or H2O, coupled with numerical simulations of the reaction mechanism. The results revealed that H2O-seeded PJs, (Ar + H2O) PJs, included O, H, and OH radicals and that for high specific powers to PJs, O and H radicals mainly contribute to combustion promotion, whereas for low specific powers, mainly OH radicals contribute to combustion promotion. At combustion promotion, (Ar + H2O) PJs were almost as effective as O2-seeded PJs, i.e., (Ar + O2) PJs, which agrees with numerical estimations. Moreover, (Ar + H2O) PJs are preferable because they cause very less wear on the electrodes of a plasma torch. Therefore, we proposed that the utilization of water PJs is a useful approach to promote combustion. © 2016 Elsevier Ltd


Matsuo T.,Kitakyushu National College of Technology | Ishii K.,Kyushu Institute of Technology
Proceedings of the SICE Annual Conference | Year: 2012

Robot are expect to be new tools for the operations and observations in the extreme environments where human has difficulties for accessing directly, deep ocean, space, nuclear plants and so on. One of the important matters to realize mobile robots for extreme environments are to establish systems in the movement and their structures which are strong enough to disturbance. A solution for realization an adaptive control system is to learn and imitate biological systems. For example, in the spinal cord of animals, neural oscillator systems called Central Pattern Generator (CPG) are proven to exist and investigated that CPG control rhythmical signals such as swimming pattern, walking locomotion, heart beats, etc. In this paper, an adaptive control system based on the feature of neural oscillators was developed and applied to motion control of a snake-like robot. © 2012 SICE.


Katayama S.,Kitakyushu National College of Technology | Takimoto T.,Kitakyushu National College of Technology
International Conference on Control, Automation and Systems | Year: 2013

In disaster, it is important to photographs and video from the sky. Aerial photographing devices such as helium gas balloons and helicopters have ever been used for information gathering activities at that time. However, these devices have a high risk because they are strongly affected by air stream at low airspace. As the new photographing device improving the above problem, in this paper, we have developed a throw type photographing device packaged in a plastic capsule egg, and proposed an automatic photographing system. The photographing device is controlled by the control circuit with an accelerometer and takes a photograph when it reaches the top of air. The accelerometer is used to calculate the time that the device until photographing. Moreover, we take aerial photographs in practice and show the effectiveness of the proposed system. © 2013 IEEE.


Fuwa Y.,Kitakyushu National College of Technology | Takimoto T.,Kitakyushu National College of Technology
International Conference on Control, Automation and Systems | Year: 2013

The gliding locomotion is defined as forward motion by the difference of friction between normal direction and tangential direction. Unlike conventional propulsion, the gliding locomotion method can move on low friction surface. Gliding locomotion robots have a simple mechanism, but it is difficult to control these robots. In previous researches, many gliding locomotion robots have been developed, and most of these robots need some actuators. In this paper, we have considered mechanism of the gliding locomotion which uses only one servo motor. Moreover, we have developed a robot with this mechanism which can move forward and turn. Then, we have shown experimental results that illustrate the effectiveness of the proposed mechanism. © 2013 IEEE.


Fukuda T.,Kitakyushu National College of Technology | Takimoto T.,Kitakyushu National College of Technology
International Conference on Control, Automation and Systems | Year: 2013

An unmanned flying boat is an aircraft which is designed to take off and land on water. The unmanned flying boat is useful as an emergency aerial observation method. In previous researches, we have developed the small flying boat controlled by the human operator. In this paper, we consider automatic control for the flying boat. However, since the flying boat is used the gyro sensor, the sensor offset may occur by that surrounding humidity and temperature changes, aging, external vibrations, mechanical stress, and so on. The sensor offset produces non-zero steady-state input and output signals, even if the flying boat is stabilized. In previous research, it has been investigated that steady-state blocking zeros of the stabilizing controller play an important role. Such a controller is called a washout controller. In this paper, we apply the washout controller to the stabilization for the flying boat with the sensor offset. Then, we show that the washout controller eliminates the bias in the steady-state and stabilizes the flying boat. Moreover, we show some simulation results which illustrate the effectiveness of the proposed control method. © 2013 IEEE.


Shigekuni T.,Kitakyushu National College of Technology | Takimoto T.,Kitakyushu National College of Technology
2011 IEEE/SICE International Symposium on System Integration, SII 2011 | Year: 2011

We consider an attitude stabilization of a quadrotor helicopter with a sensor offset by a state-derivative feedback controller. The sensor offset produces non-zero steady-state input and output, even if the quadrotor helicopter is stabilized. In previous research, it has been investigated that steady-state blocking zeros of the stabilizing controller play an important role. In this paper, we develop a design method for a dynamic state-derivative feedback controller. Then, we show that the proposed state-derivative controller eliminates the bias in the steady-state and stabilizes the quadrotor helicopter attitude. © 2011 IEEE.


Nagamura T.,Kitakyushu National College of Technology
Kobunshi | Year: 2015

Recent advances on polymeric and organic materials are reviewed from viewpoints of photoresponses and change or control of optical properties by various stimuli. The former includes photonic upconversion with noncoherent light based on tripet-triplet annihilation, ultrafast photoinduced electrochromism for all-optical signal processing in the optical telecommunication wavelength region, real-time holographic display by fast photochromism and photorefractive effects, optical polarization switching in chiral photomagnet, photoinduced changes in macroscopic shapes for future photo-driven motors, and photochemically reversible liquefaction and solidification. The latter includes a thermochromic coordination polymer with high thermal stabililty for temperature sensitive paints, high-performance electro-optic polymer modulators superior to conventional inorganic crystals, various chemical-and bio-sensing properties based on amplified fluorescence quenching or color changes in polymeric photonic crystals, mechanochromism due to stress-induced ring-opening, polymer chain dissociation, or changes in aggregation. Highly ordered photonic crystal films of block copolymers recently commercialized as notch filters for Raman spectroscopy are also shown. Efforts to fully utilize many useful properties of light are further expected. © 2015 The Society of Polymer Science. Japan.


Kaido C.,Kitakyushu National College of Technology
IEEJ Transactions on Industry Applications | Year: 2013

This paper discusses the increase in thrust with grain-oriented electrical steel sheets (GO) in plunger-type electromagnetic actuators. In these actuators, GO-laminated cores generate reluctance thrusts due to magnetic anisotropy energies in addition to conventional reluctances which are induced by the form anisotropies of the cores. Therefore, the maximum thrusts, which are induced at a displacement of about the core tooth width, increase by using GO-laminated core. The thrusts of GO cores are approximately 10% larger with high exciting current than those of non-oriented electrical steel sheet cores, and consequently may reduce copper losses by about 40% and iron losses by about 60%. © 2013 The Institute of Electrical Engineers of Japan.

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