三次元かく乱による管内対流熱伝達増進に関する研究 : 第2報,千鳥配列の場合

概要

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The enhancement of heat transfer inside a tube by means of three dimensional ribs of a regular triangle shape arranged in-line was discussed in the 1st report. Thus, the rib pitch along the tube circumference and the rib height for excellent thermal performance was found. In this report, the same experiment was performed by changing the arrangement of the ribs to the staggered manner. Furthermore, in order to make clear the mechanism of high・thermal performance, a few experiments on the flow field by means of a hot-wire anemometer and of flow-visualization (oil-film method) were performed. The results obtained show that (1) the average heat transfer coefficient, N_<um> in the staggered arrangement decreases futher than that in the in-line arrangement under n=6(N : rib number), but N_<um> is independent of the differences in rib arrangement above N=6. (2) Finally, the thermal performance in the staggered arrangement is less than that in the in-line arrangement. (3) these chracteristics depend on the behavior of three-dimensional reattachment flow downstream of the rib. A strong three dimensional reattachment flow occurs in the case of a small number of ribs in the in-line arrangement, in which interference to the flow field by adjacent ribs does not occur.
一般社団法人日本機械学会の論文
1987-03-25