A5101849925- Fluid Dynamics and Turbulent Flows
- Aerodynamics and Acoustics in Jet Flows
- Particle Dynamics in Fluid Flows
- Combustion and flame dynamics
- Magnetic confinement fusion research
- Heat Transfer Mechanisms
- Plasma and Flow Control in Aerodynamics
- Computational Fluid Dynamics and Aerodynamics
- Wind and Air Flow Studies
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Laser Design and Applications
- Plant Water Relations and Carbon Dynamics
- Meteorological Phenomena and Simulations
- Superconducting Materials and Applications
- Gyrotron and Vacuum Electronics Research
- GaN-based semiconductor devices and materials
- Fluid Dynamics and Mixing
- Semiconductor Lasers and Optical Devices
- Aerodynamics and Fluid Dynamics Research
- Advanced battery technologies research
- Fluid Dynamics and Heat Transfer
- Laser-Plasma Interactions and Diagnostics
- Optical Systems and Laser Technology
- Fluid Dynamics and Vibration Analysis
Nagoya University
2015-2024
Japanese Red Cross Fukuoka Hospital
2023
National Institute for Fusion Science
2006-2020
National Institutes of Natural Sciences
2001-2020
Tohoku University
2001-2020
Mie University
2019
The Graduate University for Advanced Studies, SOKENDAI
2016
Toyo University
2013-2014
Japan Society for the Promotion of Science
2013
Sumitomo Bakelite (Japan)
2011-2012
As the finalization of a hydrogen experiment towards deuterium phase, exploration best performance plasma was intensively performed in large helical device. High ion and electron temperatures, Ti Te, more than 6 keV were simultaneously achieved by superimposing high-power cyclotron resonance heating onneutral beam injection (NBI) heated plasma. Although flattening temperature profile core region observed during discharges, one could avoid degradation increasing density. Another key parameter...
A direct numerical simulation of a temporally developing mixing layer with passive scalar transport is performed for various Schmidt numbers (Sc = 0.25, 1, 4, and 8). Turbulent investigated near the turbulent/non-turbulent interface (TNTI), which consisting turbulent sublayer (TSL) viscous superlayer (VSL). The irrotational boundary, close to outer edge TNTI layer, detected as isosurface small vorticity magnitude. movement fluid elements relative boundary analyzed. Once non-turbulent...
The $n=2$ rotational instability is the most dangerous gross in a field-reversed theta pinch. It demonstrated for first time that completely suppressed by superposing quadrupole field which much smaller than axial confinement at separatrix. experimental threshold intensity of stabilization about 2.5 times less predicted theoretical stability analysis.
Abstract Vortex stretching and compression, which cause enstrophy production by inviscid processes, are investigated near the turbulent/non-turbulent (T/NT) interface in a planar jet using direct numerical simulation (DNS). The is analysing relationship among vorticity vector, strain-rate eigenvectors eigenvalues. statistics calculated individually for three different orientations. T/NT oriented tangential direction to interface. affected orientation because intensity of vortex depends on...
Direct numerical simulations were carried out to study the turbulence generated by a fractal square grid at Reynolds number of \documentclass[12pt]{minimal}\begin{document}$Re_{L_0}$\end{document}ReL0 = 20000 (based on inlet velocity Uin and length largest bar L0). We found that in near-field region, can generate much higher levels has better mixing performance than single grid. However, current results show produce intensity turbulent end simulation region (i.e., X/L0 ≃ 13) comparable those...
A multichannel far-infrared laser interferometer system has been developed for the measurement of spatial and temporal behaviors electron density on Large Helical Device (LHD) at National Institute Fusion Science. Of several candidates high power sources a 119 μm CH3OH was taken as probing light. The optical configuration is Michelson type with 13 channels. mounted massive stainless frame floated three vibration isolating mounts. resolution fringe counters 1/100 fringes, it corresponds to...
In this paper, direct numerical simulations are carried out to study single-square grid-generated turbulence at a Reynolds number \documentclass[12pt]{minimal}\begin{document}$Re_{L_0}$\end{document}ReL0 = 20 000 (based on the inlet velocity Uin and length of grid bar L0). Different from regular multiscale/fractal grid, here only single large square is placed center near inlet. First, we investigate evolutions characteristics (e.g., mean streamwise velocity, intensity, Taylor microscale,...
Cell gene expression is affected by both the kind and mode of growth factor stimulation (diffusive vs. non-diffusive). Epidermal (EGF) was pattern-immobilized on a polystyrene plate. Although rat phaeochromocytoma cell line PC 12 stimulated diffusible EGF, differentiation nerve (NGF), immobilized (non-diffusible) EGF differentiation. The caused long-lasting intracellular signal protein mitogen-associated MAP kinase (MAPK, also known as ERK) p38 (a subfamily MAPK superfamily) in cells, did...
AbstractThis paper describes the interferometer systems on Large Helical Device (LHD). LHD is equipped with five systems, each of which has a different operational purpose and measurable electron density range. A single-channel millimeter-wave mainly used for low-density plasmas along horizontal line sight equatorial plane. Wavelengths 1 2 mm are vibration compensation based two-color interferometry, been since first operation LHD. 13-channel CH3OH laser (wavelength 119 μm) covers almost...
A total of 11 grids in four families, including single- and multi-scale grids, are tested to investigate the development decay characteristics grid-generated turbulence. Special attention has been focused on dissipation non-equilibrium region. wide region is observed for fractal square with three iterations. The distributions Taylor microscale λ, integral length scale Lu, coefficient Cε show that a simple combination large small does not reproduce elongated regions as realized by grid. On...
In this study, we performed a direct numerical simulation (DNS) of spatially developing shear mixing layer covering both and developed regions. The aim study is to clarify the driving mechanism vortical structure partial counter-gradient momentum transport (CGMT) appearing in quasi self-similar region. present DNS, self-similarity confirmed x/L ≥ 0.67 (x/δU0 137), where L δU0 are vertical length computational domain initial thickness, respectively. However, trend CGMT observed at around kδU...
Dendritic growth at the Li anode during charging is caused by a morphological inhomogeneity of electrodeposition. In this study, we investigate dependence morphology electrodeposited on polycrystalline Cu current collector grain orientation both experimentally and numerical analysis. The experimental results show that precipitates form grains have close to (111) orientations are smallest most uniform in size. Such expected be effective for suppression dendrite growth. Numerical analysis...
Abstract A vibration technique for promoting fluid mixing and chemical reaction in a microchannel was proposed, the effects of mechanical on were experimentally examined. The fluids before flowing into oscillated by small vibrating motor through two tubes connected to channel. Instantaneous velocity concentration measured using micro PIV LIF techniques, respectively. results show that is remarkably promoted proposed technique. rate well correlated with maximum rms value normalized...
This study investigates the mixing of reactive species at a high Schmidt number (Sc ≈ 600) near turbulent/nonturbulent (T/NT) interface in planar liquid jet with chemical reaction A + B → R. Reactants and are supplied from ambient flows, respectively. An I-type hot-film probe optical fiber used for simultaneous measurements streamwise velocity, mixture fraction, concentrations all detecting T/NT interface. Statistics conditioned on time elapsed after detection analyzed. The conditional mean...
A 32-channel heterodyne radiometer for the purpose of measuring electron cyclotron emission (ECE) spectrum has been developed and installed on large helical device (LHD). Two double-sideband mixers [bandwidth (BW=2–26 GHz) with image rejection filters (high-pass low-pass filters)] are used to cover almost full spectral range second harmonic LHD ECE. The resolution each sideband receiver is Δf=1.2 GHz, which corresponds a spatial 1 cm at position half plasma radius. Gunn oscillator 132 GHz as...
The characteristics of divergence-free grid turbulence interacting with a weak spherical shock wave Mach number 1.05 are experimentally investigated. Turbulence-generating grids used to generate nearly isotropic, turbulence. turbulent Reynolds based on the Taylor microscale Reλ and Mt 49≤Reλ≤159 0.709 × 10−3≤Mt≤2.803×10−3, respectively. A is generated by diaphragmless tube. instantaneous streamwise velocity before after interaction measured hot wire probe. results show that root-mean-square...
Spatially developing planar jets with passive scalar transports are simulated for various Reynolds (Re = 2200, 7000, and 22 000) Schmidt numbers (Sc 1, 4, 16, 64, 128) by the implicit large eddy simulation (ILES) using low-pass filtering as an subgrid-scale model. The budgets of resolved turbulent kinetic energy k variance explicitly evaluated from ILES data except dissipation terms, which obtained balance in transport equations. agree well DNS experiments both high low Re cases. streamwise...