Publications

2023

T. Watanabe, K. Nagata
The response of small-scale shear layers to perturbations in turbulence
Journal of Fluid Mechanics, Accepted for publication 2023

X. Zhang, T. Watanabe, K. Nagata
Reynolds number dependence of the turbulent/non-turbulent interface in temporally developing turbulent boundary layers
Journal of Fluid Mechanics, Accepted for publication 2023

K. Nakamura, T. Watanabe, K. Nagata
Turbulent/turbulent interfacial layers of a shearless turbulence mixing layer in temporally evolving grid turbulence
Physics of Fluids, 35 045117 2023

P. D. Tung, T. Watanabe, K. Nagata
Large-eddy simulation of a flow generated by a piston-driven synthetic jet actuator
CFD Letters, Accepted for publication 2023

Y. Zheng, K. Nakamura, K. Nagata, T. Watanabe
Unsteady dissipation scaling in static and active grid turbulence
Journal of Fluid Mechanics 956 A20 2023


2022

K. Nakamura, T. Matsushima, Y. Zheng, K. Nagata, T. Watanabe
Large- and small-scale characteristics in a temporally developing shearless turbulent mixing layer
Physics of Fluids, 34 115117 2022

T. Watanabe, K. Nagata
Energetics and vortex structures near small-scale shear layers in turbulence
Physics of Fluids, 34 059114 2022

T. Watanabe, Y. Zheng, K. Nagata
The decay of stably stratified grid turbulence in a viscosity-affected stratified flow regime
Journal of Fluid Mechanics, 946 A29 2022

K. Inokuma, T. Maeda, T. Watanabe, K. Nagata
Diaphragmless shock tube with multiple air-operated valves
Experiments in Fluids, 63 121 2022

T. Akao, T. Watanabe, K. Nagata
Vertical confinement effects on a fully developed turbulent shear layer
Physics of Fluids, 34 055129 2022

K. Yamamoto, T. Ishida, T. Watanabe, K. Nagata
Experimental and numerical investigation of compressibility effects on velocity derivative flatness in turbulence
Physics of Fluids, 34 055101 2022

K. Yamamoto, T. Watanabe, K. Nagata
Turbulence generated by an array of opposed piston-driven synthetic jet actuators
Experiments in Fluids, 63 35  2022


2021

Y. Zheng, K. Nagata, T. Watanabe
Turbulent characteristics and energy transfer in the far field of active-grid turbulence
Physics of Fluids, 33 115119 2021

T. Watanabe, K. Nagata
Large-scale characteristics of a stably stratified turbulent shear layer
Journal of Fluid Mechanics, 927 A27 2021

T. Watanabe, K. Tanaka, K. Nagata
Solenoidal linear forcing for compressible, statistically steady, homogeneous isotropic turbulence with reduced turbulent Mach number oscillation
Physics of Fluids, 33 095108 2021

K. Inokuma,T. Watanabe, K. Nagata, Y. Sakai
Experimental study on shock wave modulation caused by velocity and temperature fluctuations in-cylinder wake
Physical Review Fluids, 6 063401 2021

M. Hayashi, T. Watanabe, K. Nagata
Characteristics of small-scale shear layers in a temporally evolving turbulent planer jet
Journal of Fluid Mechanics, 920 A38 2021

T. Katagiri, T. Watanabe, K. Nagata
Statistical properties of a model of a turbulent patch arising from a breaking internal wave
Physics of Fluids, 33 055107 2021

M. Hayashi, T. Watanabe, K. Nagata
The relation between shearing motions and the turbulent/non-turbulent interface in a turbulent planar jet
Physics of Fluids, 33 055126 2021

Y. Zheng, K. Nagata, T. Watanabe
Energy dissipation and enstrophy production/destruction at very low Reynolds numbers in the final stage of the transition period of decay in grid turbulence
Physics of Fluids, 33 035147 2021

Y. Tai, T. Watanabe, K. Nagata
Multi-particle models of molecular diffusion for Lagrangian simulation coupled with LES for passive scalar mixing in compressible turbulence
Computers and Fluids, 221 104886 2021

Y. Tai, T. Watanabe, K. Nagata
Implicit large eddy simulation of passive scalar transfer in compressible planar jet
International Journal for Numerical Methods in Fluids, 93 1183-1198 2021

T. Matsushima, K. Nagata, T. Watanabe
Wavelet analysis of shearless turbulent mixing layer
Physics of Fluids, 33 025109 2021


2020

T. Watanabe, C. B, da Silva, K. Nagata
Scale-by-scale kinetic energy budget near the turbulent/non-turbulent interface
Physical Review Fluids, 5 124610 2020

Y. Zhou, K. Nagata, Y. Sakai, T. Watanabe, Y. Ito, T. Hayase
Energy transfer in turbulent flows behind two side-by-side square cylinders
Journal of Fluid Mechanics, 903 A4 2020

K. Tanaka, T. Watanabe, K. Nagata
Statistical analysis of deformation of a shock wave propagating in a local turbulent region
Physics of Fluids, 32 096107 2020

T. Watanabe, K. Tanaka, K. Nagata
Characteristics of shearing motions in incompressible isotropic turbulence
Physical Review Fluids, 5 072601(R) 2020

K. Aruga, T. Watanabe, K. Nagata
Color contamination correction based on light intensity correlation in two-color, double-exposure particle tracking velocimetry
Experiments in Fluids, 61 142 2020

K. Aruga, K. Inokuma, T. Watanabe, K. Nagata, Y. Sakai
Experimental investigation of interactions between turbulent cylinder wake and spherical shock wave
Physics of Fluids, 32 16101 2020

R. Nagata, T. Watanabe, K. Nagata, C. B. da Silva
Triple decomposition of velocity gradient tensor in homogeneous isotropic turbulence
Computer & Fluids, 198 104389 2020


2019

T. Watanabe, X. Zhang, K. Nagata
Direct numerical simulation of incompressible turbulent boundary layers and planar jets at high Reynolds numbers initialized with implicit large eddy simulation
Computer & Fluids, 194 104314 2019

T. Watanabe, J. J. Riley, K. Nagata, K. Matsuda, R. Onishi
Hairpin vortices and highly elongated flow structures in a stably-stratified shear layer
Journal of Fluid Mechanics, 878 37-61 2019

K. Inokuma, T. Watanabe, K. Nagata, Y. Sakai
Statistics of overpressure fluctuations behind a weak shock wave interacting with turbulence
Physics of Fluids, 31 085119 2019

T. Watanabe, C. B. da Silva, K. Nagata
Non-dimensional energy dissipation rate near the turbulent/non-turbulent interfacial layer in free shear flows and shear free turbulence
Journal of Fluid Mechanics, 875 321-344 2019

Y. Zhou, K. Nagata, Y. Sakai, T. Watanabe
Extreme events and non-Kolmogorov -5/3 spectra in turbulent flows behind two side-by-side square cylinders
Journal of Fluid Mechanics, 874 677-698 2019

S. Tanaka, T. Watanabe, K. Nagata
Multi-particle model of coarse-grained scalar dissipation rate with volumetric tensor in turbulence
Journal of Computational Physics 389(15) 128-146 2019

K. Inokuma, T. Watanabe, K. Nagata, Y. Sakai
Statistical properties of spherical shock waves propagating through grid turbulence, turbulent cylinder wake, and laminar flow
Physica Scripta 94(4) 044004 2019

X. Zhang, T. Watanabe, K. Nagata
Passive scalar mixing near turbulent/non-turbulent interface in compressible turbulent boundary layers
Physica Scripta 94(4) 044002 2019


2018

Y. Zhou, K. Nagata, Y. Sakai, T. Watanabe
Dual-plane turbulent jets and their non-Gaussian velocity fluctuations
Physical Review Fluids 3(12) 124604 2018

T. Watanabe, K. Nagata
Integral invariants and decay of temporally developing grid turbulence
Physics of Fluids 30(10) 105111 2018

R. Nagata, T. Watanabe, K. Nagata
Turbulent/non-turbulent interfaces in temporally-evolving compressible planar jets
Physics of Fluids 30(10) 105109 2018

X. Zhang, T. Watanabe, K. Nagata
Turbulent/non-turbulent interfaces in high resolution direct numerical simulation of temporally-evolving compressible turbulent boundary layers
Physical Review Fluids 3(9) 094605 2018

T. Watanabe, J. J. Riley, K. Nagata, R. Onishi, K. Matsuda
A localized turbulent mixing layer in a uniformly stratified environment
Journal of Fluid Mechanics 849 245-276 2018

H. Sakakibara, T. Watanabe, K. Nagata
Supersonic piston synthetic jets with single/multiple orifice
Experiments in Fluids 59(5) 76 2018

Y. Tai, T. Watanabe, K. Nagata
Modeling of molecular diffusion and thermal conduction with multi-particle interaction in compressible turbulence
Physics of Fluids 30(3) 035108 2018

K. Tanaka, T. Watanabe, K. Nagata, A. Sasoh, Y. Sakai, T. Hayase
Amplification and attenuation of shock wave strength caused by homogeneous isotropic turbulence
Physics of Fluids 30(3) 035105 2018

T. Watanabe, X. Zhang, K. Nagata
Turbulent/non-turbulent interfaces detected in DNS of incompressible turbulent boundary layers
Physics of Fluids 30(3) 035102 2018


2017

T. Watanabe, J. J. Riley, K. Nagata
Turbulent entrainment across turbulent/non-turbulent interfaces in stably stratified mixing layers
Physical Review Fluids 2(10) 104803 2017

T. Watanabe, K. Nagata
Gradients estimation from random points with volumetric tensor in turbulence
Journal of Computational Physics 350 518-529 2017

T. Watanabe, R. Jaulino, R. R. Taveira, C. B. da Silva, K. Nagata, Y. Sakai
Role of an isolated eddy near the turbulent/non-turbulent interface
Physical Review Fluids 2(9) 094607 2017

T. Watanabe, C. B. da Silva, K. Nagata, Y. Sakai
Geometrical aspects of turbulent/non-turbulent interfaces with and without mean shear
Physics of Fluids 29(8) 085105 2017

K. Inokuma, T. Watanabe, K. Nagata, A. Sasoh, Y. Sakai
Finite response time of shock wave modulation by turbulence
Physics of Fluids 29(5) 051701 2017


2016

T. Watanabe, C. B. da Silva, K. Nagata
Multi-particle dispersion during entrainment in turbulent free-shear flows
Journal of Fluid Mechanics 805(R1) R1-12 2016

T. Watanabe, K. Nagata
Mixing model with multi-particle interactions for Lagrangian simulations of turbulent mixing
Physics of Fluids 28(8) 19 2016

T. Watanabe, J. J. Riley, K. Nagata
Effects of stable stratification on turbulent/non-turbulent interfaces in turbulent mixing layers
Physical Review Fluids 1(4) 044301 2016

T. Watanabe, K. Nagata
LES-Lagrangian-particles-simulation of turbulent reactive flows at high Sc number using approximate deconvolution model
AIChE Journal 62(8) 2912-2922 2016

T. Watanabe, J. J. Riley, S. M. de Bruyn Kops, P. J. Diamessis, Q. Zhou
Turbulent/non-turbulent interfaces in wakes in stably-stratified fluids
Journal of Fluid Mechanics 797(R1) 1-11 2016

T. Watanabe, Y. Sakai, K. Nagata, Y. Ito, T. Hayase
Implicit large eddy simulation of a scalar mixing layer in fractal grid turbulence
Physica Scripta 91(7) 74007 2016

T. Watanabe, C. B. da Silva, Y. Sakai, K. Nagata, T. Hayase
Lagrangian properties of the entrainment across turbulent/non-turbulent interface layers
Physics of Fluids 28(3) 031701 2016

T. Watanabe, Y. Sakai, K. Nagata, Y. Ito
Large eddy simulation study of turbulent kinetic energy and scalar variance budgets and turbulent/non-turbulent interface in planar jets
Fluid Dynamics Research 48(2) 21407 2016


2015

T. Watanabe, Y. Sakai, K. Nagata, Y. Ito, T. Hayase
LES-Lagrangian particle method for turbulent reactive flows based on the approximate deconvolution model and mixing model
Journal of Computational Physics 294 127-148 2015

T. Watanabe, Y. Sakai, K. Nagata, Y. Ito, T. Hayase
Turbulent mixing of passive scalar near turbulent and non-turbulent interface in mixing layers
Physics of Fluids 27 085109 2015

T. Watanabe, Y. Sakai, K. Nagata, O. Terashima, T. Kubo
Conditional statistics in a planar liquid jet with a second-order chemical reaction
International Journal of Heat and Mass Transfer 83, 768-780 2015

T. Watanabe, T. Naito, Y. Sakai, K. Nagata, Y. Ito
Mixing and chemical reaction at high Schmidt number near turbulent/nonturbulent interface in planar liquid jet
Physics of Fluids 27 035114 2015


2014

T. Watanabe, Y. Sakai, K. Nagata, Y. Ito, T. Hayase
Reactive scalar field near the turbulent/non-turbulent interface in a planar jet with a second-order chemical reaction
Physics of Fluids 26 105111 2014

T. Watanabe, Y. Sakai, K. Nagata, Y. Ito, T. Hayase
Enstrophy and passive scalar transport near the turbulent/non-turbulent interface in a turbulent planar jet flow
Physics of Fluids 26 105103 2014

T. Watanabe, Y. Sakai, K. Nagata, Y. Ito, T. Hayase
Vortex stretching and compression near the turbulent/nonturbulent interface in a planar jet
Journal of Fluid Mechanics 758 754-785 2014

T. Watanabe, Y. Sakai, K. Nagata, O. Terashima
Turbulent Schmidt number and eddy diffusivity change with a chemical reaction
Journal of Fluid Mechanics 754 98-121 2014

T. Watanabe, Y. Sakai, K. Nagata, Y. Ito, T. Hayase
Wavelet analysis of coherent vorticity near the turbulent/non-turbulent interface in a turbulent planar jet
Physics of Fluids 26 095105 2014

T. Watanabe, Y. Sakai, K. Nagata, O. Terashima
Experimental study on the reaction rate of a second-order chemical reaction in a planar liquid jet
AIChE Journal 60 3969-3988 2014


2013

T. Watanabe, Y. Sakai, K. Nagata, O. Terashima
Joint statistics between velocity and reactive scalar in a turbulent liquid jet with a chemical reaction
Physica Scripta T155 014039 2013

T. Watanabe, Y. Sakai, K. Nagata, O. Terashima, H. Suzuki, T. Hayase, Y. Ito
Visualization of turbulent reactive jet by using direct numerical simulation
International Journal of Modeling, Simulation, and Scientific Computing 4 1341001 2013


2012

T. Watanabe, Y. Sakai, K. Nagata, O. Terashima, T. Kubo
Simultaneous measurements of reactive scalar and velocity in a planar liquid jet with a second-order chemical reaction
Experiments in Fluids 53 1369-1383 2012



このブログの人気の投稿

The response of small-scale shear layers to perturbations in turbulence

K. Nakamura, T. Watanabe, and K. Nagata The response of small-scale shear layers to perturbations in turbulence Journal of Fluid Mechanics, 963 A31 2023 (Open Access) This article may be found at https://doi.org/10.1017/jfm.2023.316 . The article is also available  here .  Abstract The perturbation response of small-scale shear layers in turbulence is investigated with direct numerical simulations (DNS). The analysis of shear layers in isotropic turbulence suggests that the typical layer thickness is about four times the Kolmogorov scale η. Response for sinusoidal perturbations is investigated for an isolated shear layer, which models a mean flow around the shear layers in turbulence. The vortex formation in the shear layer is optimally promoted by the perturbation whose wavelength divided by the layer thickness is about 7. These results indicate that the small-scale shear instability in turbulence is efficiently promoted by velocity fluctuations with a wavelength of about 30η. Further
Read more »

WindowsにOpenFOAMを導入する（授業用）

イメージ
（2022年7月版） 書き間違いがあるかもしれないので鵜呑みにしないこと WindowsでOpenFOAM（https://www.openfoam.com/）を動かすための設定手順を紹介します。Windows Subsystem for Linux（WSL）を使ってUbuntu上でOpenFOAMを動かす方法もありますが、初めてLinuxを使う人には難しそうでした。今回はOpenFOAMのMinGWクロスコンパイル版を使います。手順通り進めればこれまでLinuxを使ったことがない人でもできるはずなので、授業の演習などでも使えると思います。 インストール環境：Windows 10、Windows 11 OpenFOAMのインストール 1. OpenFOAMのHPからMinGWクロスコンパイル版のインストーラをダウンロードする https://www.openfoam.com/download/openfoam-mingw-cross-compilation 2. ダウンロードしたファイル”OpenCFD-OpenFOAM-v2012-DP-mingw-crosscompiled-WindowsInstaller.exe”を 右クリック→管理者として実行 　 管理者として実行しないとOpenFOAMが動かない 3. インストーラの指示通り全てインストールする OpenFOAMの実行～初期設定 4. デスクトップにできたOpenFOAMのアイコンをダブルクリックして実行 インストールに問題がなければ以下のような画面が現れます ＊Linuxのコマンドで操作する cd “ディレクトリ名” [Enter] ：[ディレクトリ名]に移動 cd ..    [Enter] ：一つ上のディレクトリに移動 ls  [Enter] ：ファイル一覧を表示         pwd [Enter] ：現在のディレクトリを表示  　　など OpenFOAMのディレクトリとWindowsのフォルダを対応付ける OpenFOAMのディレクトリがWindowsでは使いづらいところにあるので、Cドライブ直下のフォルダからOpenFOAMのディレクトリを参照できるようにします。 以下、 オレンジ背景の文字 はOpenFOAM上で入力するコマンドです。 5
Read more »

Reynolds number dependence of the turbulent/non-turbulent interface in temporally developing turbulent boundary layers

X. Zhang, T. Watanabe, and K. Nagata Reynolds number dependence of the turbulent/non-turbulent interface in temporally developing turbulent boundary layers Journal of Fluid Mechanics, 964 A8 2023 This article may be found at  https://doi.org/10.1017/jfm.2023.329 . Accepted manuscript is available here.  This version is free to view and download for private research and study only.  Abstract Direct numerical simulations (DNS) of temporally developing turbulent boundary layers are performed with a wide range of Reynolds numbers based on the momentum thickness  Reθ=2000-13000 for investigating the Reynolds number dependence of the turbulent/non-turbulent interface (TNTI) layer. The grid spacing in the DNS is determined carefully such that small-scale turbulent motions near the TNTI are well resolved. The outer edge of the TNTI layer, called the irrotational boundary, is detected with vorticity magnitude. The mean thicknesses of the TNTI layer, δTNTI, turbulent sublayer,  δTSL , and viscou
Read more »