Fujihiro Hamba
University of Tokyo
Magnetic fieldPhysicsLarge eddy simulationStatistical physicsShear flowReynolds stressK-epsilon turbulence modelReynolds stress equation modelTurbulence kinetic energyConvection–diffusion equationOpen-channel flowDirect numerical simulationK-omega turbulence modelTurbulenceVorticityTurbulence modelingHelicityReynolds-averaged Navier–Stokes equationsMathematicsMechanicsClassical mechanics
68Publications
15H-index
639Citations
Publications 64
#1Hideaki Miura (National Institutes of Natural Sciences, Japan)H-Index: 7
#2Fujihiro HambaH-Index: 15
A new sub-grid-scale model is developed for studying influences of the Hall term on macroscopic aspects of magnetohydrodynamic turbulence. Although the Hall term makes numerical simulations extremely expensive by exciting high-wave-number coefficients and makes magnetohydrodynamic equations stiff, studying macroscopic aspects of magnetohydrodynamic turbulence together with the Hall term is meaningful since this term often influences not only sub-ion-scales but also macroscopic scales. A new sub-...
#1Mizuki Kuroha (UTokyo: University of Tokyo)H-Index: 2
#2Shohei Nambu (UTokyo: University of Tokyo)H-Index: 3
Last. Kazuyuki Ishii (UTokyo: University of Tokyo)H-Index: 27
view all 8 authors...
: Fluid dynamics, resulting from the macroscopic mechanical rotation of either a rotary evaporator or a magnetic stirrer, has been shown to selectively induce one of two enantiomers (mirror-image structures) in certain nanoscale supramolecules. As an alternative to giving a chiral twist to synthesized supramolecules or polymers, it is a challenge to reproducibly prepare chiral species by only using macroscopic mechanical rotations. Demonstrated here is a highly reproducible method for rotary-eva...
#1Fujihiro HambaH-Index: 15
An inverse cascade is found in the energy transfer in scale space of channel flow. The conditional average of the velocity field associated with the inverse cascade or negative subgrid-scale production reveals a long streamwise vortex near the wall with a short vortex in the upstream region.
#1Kazuhiro Inagaki (UTokyo: University of Tokyo)H-Index: 3
#2Taketo ArikiH-Index: 4
Last. Fujihiro Hamba (UTokyo: University of Tokyo)H-Index: 15
view all 3 authors...
In this study, realizable algebraic Reynolds stress modeling based on the square root tensor [Phys. Rev. E \textbf{92}, 053010 (2015)] is further developed for extending its applicability to more complex flows. In conventional methods, it was difficult to construct an algebraic Reynolds stress model satisfying the realizability conditions when the model involves higher-order nonlinear terms on the mean velocity gradient. Such higher-order nonlinear terms are required to predict turbulent flows w...
#1Mizuki Kuroha (UTokyo: University of Tokyo)H-Index: 2
#2Shohei NambuH-Index: 3
Last. Kazuyuki Ishii (UTokyo: University of Tokyo)H-Index: 27
view all 8 authors...
#1Kazuhiro InagakiH-Index: 3
#2Taketo ArikiH-Index: 4
Last. Fujihiro HambaH-Index: 15
view all 3 authors...
In this study, realizable turbulence modeling based on the square root tensor of the Reynolds stress [Phys. Rev. E \textbf{92}, 053010 (2015)] is further developed for extending its applicability to more complex flows. In conventional methods, it was difficult to construct a turbulence model satisfying the realizability conditions when the model involves higher-order nonlinear terms on the mean velocity gradient. Such higher-order nonlinear terms are required to predict turbulent flows with thre...
#1Fujihiro Hamba (UTokyo: University of Tokyo)H-Index: 15
#2Kouta Kanamoto (UTokyo: University of Tokyo)H-Index: 1
The K–$$\varepsilon$$ model used in turbulence simulations involves the transport equations for the turbulent kinetic energy and its dissipation rate. In contrast to the turbulent energy equation derived from the Navier–Stokes equation, the transport equation for the dissipation rate has been modeled empirically and has less of a theoretical grounding. An analysis of the dependence of terms in the exact transport equation on the Reynolds number $$\textit{Re}$$ has suggested that the two dominan...
#1Fujihiro HambaH-Index: 15
#1Hideaki MiuraH-Index: 7
#2Fujihiro HambaH-Index: 15
#1Kazuhiro Inagaki (UTokyo: University of Tokyo)H-Index: 3
#2Fujihiro Hamba (UTokyo: University of Tokyo)H-Index: 15
It is known that turbulent energy is rapidly transferred in the direction of the rotation axis in a rotating system, in comparison with the nonrotating case. A new turbulence model of the energy flux predicting this phenomenon is proposed and discussed in terms of turbulent helicity.