A5028668802- Meteorological Phenomena and Simulations
- Climate variability and models
- Combustion and flame dynamics
- Tropical and Extratropical Cyclones Research
- Fire dynamics and safety research
- Oceanographic and Atmospheric Processes
- Advanced Combustion Engine Technologies
- Wind and Air Flow Studies
- Computational Fluid Dynamics and Aerodynamics
- Fluid Dynamics and Turbulent Flows
- Solidification and crystal growth phenomena
- Atmospheric aerosols and clouds
- Asymmetric Synthesis and Catalysis
- Physics of Superconductivity and Magnetism
- Combustion and Detonation Processes
- Fluid Dynamics and Heat Transfer
- Coal Combustion and Slurry Processing
- Advanced Control Systems Optimization
- Radiative Heat Transfer Studies
- Advanced Condensed Matter Physics
- Urban Heat Island Mitigation
- Plant Water Relations and Carbon Dynamics
- Respiratory Support and Mechanisms
- Differential Equations and Numerical Methods
- Aluminum Alloy Microstructure Properties
Japan Agency for Marine-Earth Science and Technology
2013-2024
Tokyo University of Science
2024
Nihon Kohden (Japan)
2014-2020
Tokyo Dental College
2018
Meijo University
2016
Tohoku University
2004-2012
Kyoto University
1998-2010
Environmental Simulation Center
2009
Central Research Institute of Electric Power Industry
2006-2008
Tokyo Institute of Technology
2007
The validity of a steady-flamelet model and flamelet/progress-variable approach for gaseous spray combustion is investigated by two-dimensional direct numerical simulation (DNS) jet flames, the characteristics are analysed. A modified approach, in which total enthalpy rather than product mass fraction chosen as progress variable, also examined. DNS with an Arrhenius formation, chemical reaction directly solved physical flow field, performed reference to validate models. results show that...
We report on the magnetic properties of double-layered perovskite (CuCl)LaNb 2 O 7 with a square lattice S =1/2 Cu 2+ ions, prepared by topotactic ion-exchange reactions. Magnetic susceptibility exhibits thermal-activated behavior, and analysis data suggests competing ferro- antiferromagnetic exchanges for first- second-nearest-neighbor bonds, respectively. Neutron scattering experiments provide explicit evidence spin-singlet ground state an energy gap 2.3 meV. The well-defined low-lying...
Abstract The three-dimensional dynamical core of an atmospheric general circulation model employing Yin–Yang grid is developed and examined. Benchmark test cases based on the shallow-water configuration are first performed to examine validity two-dimensional calculations. experiments show that simulates reasonable flow fields with second-order accuracy. validation then extended features where capability has not been tested before: global mountain gravity wave, long-term integration, life...
We have developed a spectral cumulus parameterization using cloud-resolving model. This includes new of the entrainment rate which was derived from analysis cloud properties obtained model simulation and valid for both shallow deep convection. The scheme examined in single-column experiment compared with existing Gregory (2001, Q J R Meteorol Soc 127:53–72) (GR scheme). results showed that GR simulated more diluted convection than scheme. To further validate physical performance...
Mechanisms of interactions among different scale phenomena play important roles for forecasting weather and climate. Multi-scale Simulator the Geoenvironment (MSSG), which deals with multi-scale multi-physics phenomena, is a coupled non-hydrostatic atmosphere-ocean model designed to be run efficiently on Earth Simulator. We present simulation results world-highest 1.9km horizontal resolution entire globe regional heavy rain 1km 5m horizontal/vertical urban area simulation. To gain high...
High-field magnetization measurements have been performed up to 56 T for a two-dimensional S = 1/2 frustrated square-lattice antiferromagnet (CuCl)LaNb 2 O 7 , recently discovered spin gap system (Δ/ k B 26.7 K). It is found that the closes at surprisingly low field H c1 10.3 compared with expected from zero-field g µ 18.4 T). For > exhibits linear increase without any trace of anomalies such as fractional plateaus until it saturates c2 30.1 T. This means gapless phase, where field-induced...
Large-eddy simulation (LES) is applied to a pulverized coal combustion field in test furnace with practical advanced low NOx burner called CI-α burner, and its validity investigated by comparing the experiment. The motion of particles calculated Lagrangian method parcel model. In modeling, three chemical processes are considered, namely devolatilization, char gaseous combustion. direct closure SSFRRM(scale similarity filtered reaction rate model) used as turbulent results show that swirling...
The thermal conductivity of molten copper was measured by the periodic laser-heating method, in which a static magnetic field superimposed to suppress convection an electromagnetically levitated droplet, extend measurement range method up relatively high conductivity. Before measuring conductivity, optimum conditions for field, laser frequency heating and sample diameter were investigated numerical simulation both flow fields droplet presence melt convection. As result, temperature...
A 1/3 magnetization plateau was recently observed in the layered perovskite $(\text{CuBr}){\text{Sr}}_{2}{\text{Nb}}_{3}{\text{O}}_{10}$ with $S=1/2$ CuBr layers. In order to control cell size and thus exchange parameters, we have prepared an isostructural series of $(\text{CuBr}){A}_{2}{B}_{3}{\text{O}}_{10}$ ($A=\text{Ca}$, Sr, Ba, Pb; $B=\text{Nb}$, Ta) investigated magnetic properties. We found that stability is systematically tunable by lattice parameter $a$. substantial role played...
The normal spectral emissivity of molten copper was determined in the wavelength range 780–920 nm and temperature 1288–1678 K, by directly measuring radiance emitted an electromagnetically levitated droplet under a static magnetic field 1.5 T. spectrometer for measurement calibrated using relation between theoretical blackbody from Planck's law light intensity quasi-blackbody radiation source measured at given temperature. As result, as 0.075 ± 0.011 807 nm, it found that its dependence is...
Abstract We implemented a spectral cumulus parameterization based on cloud‐resolving model (SC scheme) in the icosahedral nonhydrostatic atmospheric (ICON‐A). compared resulting simulated climatology and tropical variability with results from standard version of ICON‐A using variant Tiedtke‐Nordeng scheme (TK observational reanalysis data. The climatological errors SC were similar to those TK scheme, but several biases, such as properties meridional winds precipitation pattern western...
Abstract The influence of a new spectral cumulus parametrization (the scheme) on simulating global tropical cyclone (TC) activity in an Atmospheric General Circulation Model (AGCM) is investigated. Experiments are performed using AFES (AGCM for the Earth Simulator) and two different convection schemes – original scheme AGCM Emanuel scheme. result shows that both can capture qualitative features TC terms climatology, variability, intensity. However, simulates genesis track density better than...
In order to quantitatively investigate the effect of convection in an electromagnetically levitated molten iron droplet on thermal conductivity measured by electromagnetic levitation (EML) technique presence a static magnetic field, numerical simulations melt and measurements with periodic laser heating method were carried out. addition, was EML technique, then compared values obtained numerically. It found that could sufficiently explain measurement field. is suggested field 10 T enough...
Abstract The weighted essentially non‐oscillatory (WENO) scheme is applied to a cloud‐resolving model and used for the cloud edge problem. Validity tested using three idealized experiments results are compared with those of recent flux‐corrected transport (FCT) schemes. In all experiments, WENO simulates energy properties edges better than FCT schemes do. Because can capture more sharply, buoyancy simulated without numerical diffusion. increased also causes enhancement convection cycle in...
Abstract Hindcast experiments were performed for heavy rainfall events over Japan in July 2020 using a regional atmospheric model and coupled to examine the importance of ocean prediction predicting events. Both models able predict first peak accumulated western occurring half July. However, only predicted second that occurred Sea level pressure (SLP) low‐level moisture inflow originating from an existing river (AR) found differ each model. In model, error associated with inaccurate grew...
PID control is widely used as a basic technology in industries today, but tuning of systems not always easy. Based on model-driven concept, we developed system, named MD controller, combining with PD local feedback, IMC and set point filter. This paper provides brief introduction new model driven two-degrees freedom TDOF shows some case studies results. We have confirmed that can show better results compared conventional control.
A shallow convective closure (shallow closure) was introduced in a spectral cumulus parameterization (spectral scheme), and the validity evaluated using an atmospheric general circulation model (AGCM) Atmospheric Model Intercomparison Project (AMIP) experiments. The scheme with improved simulated climatology variability as compared only. enhanced convection, leading to improvements dry bias tropics cold extratropics. interannual variabilities were comparable regardless of closure; however,...
Responses of rainfall trends to land surface properties (roughness length and sensible heat flux) under weak wind shear conditions were investigated by numerical simulation idealized experiments. The results show that total amount, spatial pattern intensity highly affected the difference in flux rather than roughness length. initiation time for occurrence became more delayed intensified as given decreased. A smaller a larger increased convective available potential energy before occurrence,...
Newly developed noncontact modulation laser calorimetry has enabled us to measure accurate thermophysical properties such as thermal conductivity and heat capacity of high temperature liquid metals with suppressing chemical reactions convections. However, in spite the demand for input parameters precise numerical simulation casting welding processes, it is still difficult those iron (Fe). The difficulty caused by density electrical resistivity Fe. In this study we designed a new levitation...
Abstract Large‐eddy simulations using the flamelet models are applied to turbulent reacting liquid flows and validated by comparing with experiments. The computations performed for two reaction conditions, namely a rapid moderately fast in grid‐generated flow. For models, both steady model unsteady Lagrangian tested. A second‐order, irreversible, isothermal is considered. results show that inherently developed combustion applicable flows, provided coefficient evaluating subgrid scale...