リブ状粗面をもつ長方形流路の助走区間における熱(物質)伝達特性

概要

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Experimental study has been conducted on local heat (mass) transfer characteristics in the entrance region of rectangular ducts with/without rib-roughened long side walls using the naphthalene sublimation technique. Three rib heights and four rib pitches have been tested. In the smooth duct, the laminar boundary layers are first formed near the duct entrance and then begin to transit to turbulent ones from the duct corners. The turbulent region develops from the corner toward the duct center as the flow proceeds downstream ; therefore, the local mass transfer rates change in both the streamwise and spanwise directions. In the rib-roughened duct as well, the local mass transfer rates vary in not only the streamwise but also the spanwise directions very near the duct entrance ; the location of the maximum local mass transfer rate caused by the flow reattachment moves upstream as the adjacent wall is approached. It has been found that the influence of rib height on the local mass transfer rate is more pronounced near the corner than in the duct center region.
一般社団法人日本機械学会の論文
1997-04-25