TED-AJ03-629 NUMERICAL STUDY ON CHAOTIC BEHAVIORS OF FLOW THROUGH POROUS MEDIA
スポンサーリンク
概要
- 論文の詳細を見る
A numerical study has been made on chaotic behavior of the forced convection in the transition regime from laminar to turbulent flow. The Forchheimer flow resistance and the dispersion can be observed in the flow through porous media at high Reynolds numbers. Masuoka and Takatsu (1996) proposed a turbulence model based on the concept of two types vortices. The mixing of the interstitial vortex mainly contributes to the Forchheimer flow resistance, and the mixing of the pseudo-vortex, which is caused by the forced flow distortion around the solid particle, to the thermal dispersion. Furthermore, Takatsu and Masuoka (1998) have obtained the experimental evidences of turbulent vortices related to the momentum and energy transport in the flow through porous media at high Reynolds numbers, and verified the basic characteristics of the turbulence for the flow through porous media. Examining a transition regime to turbulent flow is of importance in understanding a nature of the turbulence in porous media. Dybbs and Edwards (1984) recognized a highly unsteady and chaotic flow for Re_d>300,which qualitatively resembles the turbulent flow, from the flow visualization in the complex rod bundle porous media. Masuoka et al. (2000) experimentally examined the chaotic behavior of flow across a bank of tubes in a narrow gap utilized as a porous model. The flow visualizations and the data analysis of the time series of velocity fluctuations show the existence of the chaotic flow in porous media. They found that the experimental maximum Lyapunov exponents become positive for Re>∿60 and that the weak chaos governed by the laminar flow is induced for ∿60<Re<∿100. While the correlation dimension increased with the increase of Reynolds number for ∿60<Re<∿100,it became almost constant for ∿100<Re<∿200. Then, Masuoka et al. (2000) indicated that the Lyapunov exponent rapidly increases with the increase of Reynolds number for Re>∿300,which corresponds to the transition to the turbulent flow through porous media. The present study solves the governing equations at a pore-scale level, with use of square rods arranged periodically. The present numerical simulation confirms the above experimental chaotic behavior and clarifies the effects of chaotic behavior of the flow to the transport phenomena in porous media. [figure]
著者
-
Masuoka Takashi
Department Of Mechanical Engineering And Science Kyushu University
-
Takatsu Yasuyuki
Department of Mechanical Engineering, Faculty of Engineering, Kyushu Institute of Technology
-
Kakimoto Yasushi
Department Of Mechanical Engineering Science Kyushu University
-
SHITAMI Masaya
Department of Mechanical Engineering Science Kyushu University
-
Takatsu Yasuyuki
Department Of Mechanical Engineering Faculty Of Engineering Kyushu Institute Of Technology
-
Takatsu Yasuyuki
Department Of Mechanical Engineering Hiroshima Kokusai Gakuin University
関連論文
- Forced Convection around Porous Obstacle
- Critical Heat Flux Prediction of Subcooled Pool Boiling Based on the Microlayer Model
- TED-AJ03-629 NUMERICAL STUDY ON CHAOTIC BEHAVIORS OF FLOW THROUGH POROUS MEDIA
- Conjugated Heat Transfer on a Horizontal Surface Impinged by Circular Free-Surface Liquid Jet(Heat and Mass Transfer)
- Buoyant Plume through a Permeable Porous Layer Located above a Line Heat Source in an Infinite Fluid Space
- Buoyancy-Driven Channelling Flow in Vertical Porous Layer
- Transient Condensing Two-Phase Flow Through an Initially Subcooled Porous Medium
- Optimal Partition for Suppression of Thermal Convection
- Chaotic Behaviors of Forced Convection in Porous Media
- Study on Vortex Diffusion in Porous Media
- Estimation of Condensation Coefficient from Dropwise Condensation Heat Transfer