角柱の挿入により非定常化した平行平板間流れと熱伝達 : 第2報, 流れの統計的性質と時間変化特性

概要

論文の詳細を見る
Two-dimensional numerical computation has been made for unsteady flow in a channel obstructed by an inserted square rod. The results of the computation made for the inlet flow with a parabolic velocity profile and for specific values of channel Reynolds number and rod size are studied in detail. In particular, the statistical features and the time variation of the flow are discussed based on the obtained results. From the statistical viewpoint, the flow is demonstrated to be highly periodical, therefore almost free from randomness or irregularity so that it is quite different from turbulent flows. However, the obtained results reveal that the momentum transfer is enhanced due to the apparent shear stress resulting from the nonzero value of cross correlation between the streamwise and lateral components of fluctuating velocity. Two characteristic features are discussed in detail for the time variation of the flow. One is related to the lateral motion of the vortices shed from the rod highlighted in the previous study. It is discussed in terms of the periodical variation of the separation vorticity layers formed from both sides of the rod. Another is the formation of a 'wall vortex', which affects the wall heat transfer, as will be described in the next paper, and is formed under the lifted tip of the wall vorticity layer.
一般社団法人日本機械学会の論文
1991-04-25