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Journal Articles

Experimental study on interfacial area transport of two-phase bubbly flow in a vertical large-diameter square duct

Shen, X.*; Sun, Haomin; Deng, B.*; Hibiki, Takashi*; Nakamura, Hideo

International Journal of Heat and Fluid Flow, 67(Part A), p.168 - 184, 2017/10

https://doi.org/10.1016/j.ijheatfluidflow.2017.08.006

Times Cited Count：17 Percentile：62.14(Thermodynamics)

An experimental study on upward bubbly air-water flows in a vertical large-diameter square duct have been performed by mainly using four-sensor probes. Local measurements of interfacial area concentration (IAC), void fraction, 3D bubble velocity vector and bubble diameter at 3 axial positions were conducted. Although the interfacial area transport equation (IATE) and its bubble coalescence and breakup models have already played an important role in predicting the IAC in general two-phase flow fields, they are mainly developed based on the two-phase flow experimental data taken in round pipes or small diameter channels. To confirm their usability in large-diameter square duct, this study has evaluated the 1D one-group IATE with its 6 sets of bubble coalescence and breakup models with the presently-obtained database. It was found the relative error between the best prediction and the database was 25%.

Journal Articles

Transport threshold model of subsonic neoclassical tearing modes in tokamaks

Mikhailovskii, A. B.*; Shirokov, M. S.*; Tsypin, V. S.*; Konovalov, S. V.; Ozeki, Takahisa; Takizuka, Tomonori; Galvo, R. M. 0.*; Nascimento, I. C.*

Physics of Plasmas, 10(10), p.3975 - 3983, 2003/10

https://doi.org/10.1063/1.1604776

Times Cited Count：8 Percentile：25.78(Physics, Fluids & Plasmas)

A transport threshold model of subsonic neoclassical tearing modes (NTMs) in tokamaks is developed. The basic procedure is to include the velocity-dependent term into the single-fluid heat-conductivity equation. and to supply the parallel plasma motion equation. These equations permit the determination of the perturbed plasma temperature and the bootstrap current drive of NTMs, for both strong and weak perpendicular heat transport. It is shown that the subsonic NTMs transport threshold model can be more realistic than the standard transport threshold model of NTMs.

Journal Articles

Zonal flows in gyrofluid simulations of slab electron temperature gradient turbulence

Li, J.; Kishimoto, Yasuaki

Physics of Plasmas, 9(4), p.1241 - 1254, 2002/04

https://doi.org/10.1063/1.1455628

Times Cited Count：37 Percentile：72.43(Physics, Fluids & Plasmas)

Zonal flows can be generated by drift wave turbulence through the nonlinear interactions. 3-D gyrofluid simulations show that in a turbulent system driven by electrostatic sheared slab electron temperature gradient(ETG) modes, the excitation of zonal flows is a slower process that indicates the amplitudes grow up approximately proportionally to time. The zonal flows are very weak comparing with the background turbulence and hardly work for suppressing the turbulent electron heat transport. The dynamics of zonal flows is numerically explored through starting zonal flow component in the quasi-steady state.

Journal Articles