瀬戸内海水理模型における縮率効果に関する実験的研究

Abstract

Reported herein is a comparative study of two hydraulic models of the Seto Inland Sea inorder to better understand the scale effect on the similarity principle of the hydraulic model.The larger model is built with scale ratios of 1 to 2000 and 1 to 160 in horizontal and verticaldirections respectively. The smaller model has scale ratios of 1 to 50, 000 and 1 to 500 in hori-zontal and vertical directions respectively. The semi-diurnal (M2) tide was generated in themodels and it was found that both models exhibit the same tendency of yielding greater tidalranges around the inner portion of the models than corresponding prototype values, thoughwith a slightly different spatial pattern. This difference has been corrected by addition of con-crete blocks in the larger model and wire mesh in the smaller model around narrow straints.Flow velocities and one-dimensional dispersion-coefficients are found to be twice larger and asmuch as ten times larger, respectively, in the smaller model than in the larger model suggest-ing possible effect of flow spearation.