TED-AJ03-549 NUMERICAL IDENTIFICATION OF LAMINAR/TURBULENT FLOW FOR NATURAL CONVECTION IN SQUARE CAVITY

スポンサーリンク

概要

• 論文の詳細を見る

• Buoyancy-driven flow in differentially heated enclosures occurs in a wide variety of engineering applications such as nuclear reactor insulation, ventilation of rooms, solar energy collection, crystal growth in liquids, double-window installation. It was reported that different turbulence closure models may yield different predictions on the critical Rayleigh number (Ra) for a given buoyancy-driven flow. A benchmark problem which is the air in a square cavity heated by a vertical side is studied with the Rayleigh number (Ra_<cr> ranging from laminar, transition to turbulent regimes. The transport equations consisting of mass, momentum and energy conservation are numerically solved using the SIMPLER algorithm and the QUICK scheme. Two analysis methods of power spectrum and phase trajectory are adopted to distinguish the flow pattern in the cavity. The objective of this study is twofold. The first one is to study how the flow evolves from laminar, transition, to turbulent regimes with increasing Ra values. The second one is to identify the distribution of laminar/turbulent flow regions for the case with the Ra values slightly larger than (Ra)_<cr> Fives cases with Ra=(10)^7,5×(10)^7,(10)^8,4×(10)^8,and 6×(10)^8 ranging from laminar to turbulent regimes are investigated in the study. It is shown that there appear chaotic motion (weakly turbulent) in some regions of the cavity for the cases of Ra=4×(10)^8 and 6×(10)^8. The enclosed figure shows two distribution contours of laminar/turbulent flow regions for Ra=4×(10)^8 and Ra=6×(10)^8. The portion of turbulent flow regime is clearly broadened with the increasing Ra. The information of the laminar/turbulence distribution contour can be used in numerical benchmark tests for the validation of turbulence closure models when applying to the natural convection around the transition from laminar to turbulence. [figure]

• 一般社団法人日本機械学会の論文

著者

• Wu Wen

  Department Of Aeronautics And Astronautics National Cheng Kung University

• Chang Keh

  Department of Aeronautics and Astronautics National Cheng Kung University

関連論文

• Aleyrodidae of Taiwan (Homoptera) : Part IV. Unrecorded species
• Aleyrodidae (Homoptera) of Taiwan : Part III. Aleuromarginatus CORBETT
• Aleyrodidae of Taiwan : Part II. Asialeyrodes CORBETT
• Aleyrodidae of Taiwan : Part I. Rhachisphora QUAINTANCE et BAKER
• TED-AJ03-549 NUMERICAL IDENTIFICATION OF LAMINAR/TURBULENT FLOW FOR NATURAL CONVECTION IN SQUARE CAVITY
• The Taiwanese Species of the Ant Genus Smithistruma (Hymenoptera, Formicidae)
• Adult Asymptomatic Hamartoma in the Distal Esophagus: A Rare Case

スポンサーリンク