Numerical investigation on unstable behaviors of cellular premixed flames at low Lewis numbers based on the diffusive-thermal model and compressible Navier-Stokes equations

Thwe Thwe, A.; Kadowaki, Satoshi; Hino, Ryutaro

Journal of Thermal Science and Technology (Internet), 13(2), p.18-00457_1 - 18-00457_12, 2018/12

https://doi.org/10.1299/jtst.2018jtst0034

Two dimensional unsteady calculations of reactive flows were performed in large domain to investigate the unstable behaviors of cellular premixed flames at low Lewis numbers based on the diffusive-thermal (D-T) model and compressible Navier-Stokes (N-S) equations. The growth rates obtained by the compressible N-S equations were large and the unstable ranges were wide compared with those obtained by the D-T model equations. When the length of computational domain increased, the number of small cells separated from large cells of the cellular flame increased drastically. The stronger unstable behaviors and the larger average burning velocities were observed especially in the numerical results based on the compressible N-S equations. In addition, the fractal dimension obtained by the compressible N-S equations was larger than that by the D-T model equations. Moreover, we confirmed that the radiative heat loss promoted the instability of premixed flames at low Lewis numbers.

Key achievements in elementary R&D on water-cooled solid breeder blanket for ITER test blanket module in JAERI

Suzuki, Satoshi; Enoeda, Mikio; Hatano, Toshihisa; Hirose, Takanori; Hayashi, Kimio; Tanigawa, Hisashi; Ochiai, Kentaro; Nishitani, Takeo; Tobita, Kenji; Akiba, Masato

Nuclear Fusion, 46(2), p.285 - 290, 2006/02

https://doi.org/10.1088/0029-5515/46/2/012

This paper presents significant progress in R&D of key technologies on the water-cooled solid breeder blanket for the ITER-TBM in JAERI. By the improvement of heat treatment process for blanket module fabrication, a fine-grained microstructure of F82H, can be obtained by homogenizing it at 1150 C followed by normalizing at 930 C after the HIP process. Moreover, a promising bonding process for a tungsten armor and an F82H structural material was developed by using a uniaxial hot compression without any artificial compliant layer. Also, it has been confirmed that a fatigue lifetime correlation, which was developed for ITER divertor, can be applicable for F82H first wall mock-up. As for R&D on a breeder material, LiTiO, the effect of compression loads on thermal conductivity of pebble beds has been clarified. JAERI have extensively developed key technologies for ITER-TBM, and now steps up into an engineering R&D stage, where integrated performance of TBM structures will be demonstrated by scalable mock-ups.

Study on the efficiency of effective thermal conductivities on melting characteristics of latent heat storage capsules

Shiina, Yasuaki; Inagaki, Terumi*

International Journal of Heat and Mass Transfer, 48(2), p.373 - 383, 2005/01

https://doi.org/10.1016/j.ijheatmasstransfer.2004.07.043

Improvement of thermal conductivity of phase change medium would be one of the effective techniques to reduce phase change time in latent heat storage technology. Thermal conductivity would be improved by saturating phase change materials (PCM) in porous metals. Efficiency of effective thermal conductivity on melting time is studied by analyzing melting characteristics of a heat storage circular capsule where porous metal saturated by PCM is inserted. Results show that considerable reduction in melting time was obtained, especially for low conductivity PCMs and for high heat transfer coefficient. Trial estimation of optimum porosity was presented under the conditions of keeping high latent heat capacity and high reduction rate of melting time. Optimum porosity decreases with increase in heat transfer coefficient.

Present research status on divertor and plasma facing components for fusion power plants

Suzuki, Satoshi; Ueda, Yoshio*; Tokunaga, Kazutoshi*; Sato, Kazuyoshi; Akiba, Masato

Fusion Science and Technology, 44(1), p.41 - 48, 2003/07

https://doi.org/10.13182/FST03-A308

no abstracts in English

Neutronics study on the JAERI 5MW spallation neutron source; Neutronic performance of the reference target-moderator-reflector system and the target shape/size effects

Teshigawara, Makoto*; Watanabe, Noboru*; Takada, Hiroshi; Kai, Tetsuya; Nakashima, Hiroshi; *; Oyama, Yukio; Ikeda, Yujiro; Kosako, Kazuaki*

JAERI-Research 99-020, 33 Pages, 1999/03

JAERI-Research-99-020.pdf:1.83MB

no abstracts in English

Temperature effect on critical mass and kinetic parameter / of VHTRC-4 core

Yamane, Tsuyoshi; Akino, Fujiyoshi;

PHYSOR 96: Int. Conf. on the Physics of Reactors, 2, p.E290 - E299, 1996/00

no abstracts in English

Assessment of REFLA/TRAC code for system behavior during reflood phase in a PWR LOCA with CCTF data

; Onuki, Akira; Murao, Yoshio

Proc. of the 2nd Int. Conf. on Multiphase Flow 95-Kyoto, 0, p.P2_37 - P2_44, 1995/00

no abstracts in English

Future potential of nuclear heat utilization in energy, economy and environment

; Sato, Osamu; ; *

Nucl. Eng. Des., 136, p.211 - 217, 1992/00

https://doi.org/10.1016/0029-5493(92)90131-E

no abstracts in English

Liquid-metal heat transfer for the first wall and limiter/divertor plates of fusion reactors

M.Z.Hasan*; Kunugi, Tomoaki

Heat Transfer-Minneapolis,1991 (AIChE Symp. Ser. No. 283), p.67 - 73, 1991/00

no abstracts in English

Heat transfer with nonuniform heat flux for PFC of fusion reactors

Kunugi, Tomoaki

SAND-92-0222, p.3-14 - 3-26, 1991/00

no abstracts in English