Co-Investigator(Kenkyū-buntansha) |
SUZUKI Takeshi Mechanical Engineering Laboratory, National Institute of Advanced Industrial Science and Technology, Department of Computational Science, Senior Researcher, 計算科学研究部門, 主任研究官
NAKAMURA Yuji Nagoya University, Graduate School of Engineering, Reseach Associate, 工学研究科, 助手 (50303657)
TSUNODA Hiroyuki Yamanashi University, School of Engineering, Associate Professor, 工学部, 助教授 (10207433)
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Research Abstract |
The progress and results of the research are summarized in the following, Object (A) <Simulations by the Stochastic Model>___- The axisimmetric plume from a point source in the fully developed turbulent pipe flow has been simulated by the probability density function method (pdf) method. The particle velocity was modeled by a stochastic differential equation (a generalized Langevin model expressed in the cylindrical coordinates), and the two kinds of molecular mixing model, i.e., the Dopazo's deterministic model and the modified Curl's model have been used. It is found that both models are useful to predict the radial profiles of the mean concentration and fluctuation r.m.s.concentration. Next, the reactive mixing layer with second-order chemical reaction in the grid-turbulence has been simulated by the pdf method. It is found that as the molecular mixing model the binomial Langevin model is suitable to predict the pdf of the reactive scalar quantities. Further, the new generalized Lange
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vin model for the axisymmetric turbulent jet has been developed, and the conserved scalar field has been simulated by the Dopazo's model. Consequently, the scalar moments up to the second-order could be predicted satisfactorily. Object (B) <Simulations by the Random Fourier Modes Method>___- At first, a new method to simulate the turbulent field around a two-dimensional circular cylinder has been developed by the combination of the random Fourier modes method, the rapid distortion theory and the wake vortex shedding model. Then, the distribution of the second-order moment and spectrum of the velocity field have been calculated and compared with the experimetal data. It is found that the simulation results show good agreements with the experimental data. Next, the reactive scalar mixing layer has been simulated by the combination of the randam Fourier modes method and two-particle backward diffusion technique or the molecular mixing model of the pdf method. The agreements between the simulation results and experimental data could be observed. Further, the simulation method of the turbulent flow around the various bluff bodied has been developed, and the statistics of the material line in the homogeneous isotropic turbulence has been investigated by the random Fourier modes method. Less
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