31. A Long Wave in the Vicinity of an Estuary[II] : An Analysis by the Method of the Buffer Domain

Abstract

Succeeding the previous study on long waves in the vicinity of an estuary, the theory is developed, in this paper, under the second approximation to inquire numerically into the behaviors of the waves around an estuary. When the approximation proceeds from the first to the second one, the minute behaviors of the waves come to light, which do not appear in the first approximation. The newly exposed facts are as follows:- High waves appear in the interior of the canal, which is due to the diffraction of the waves in the estuary. The way in which the incident waves invade the canal is such that the waves first advance towards the center of the mouth of the canal from the open sea(of which the crest line is a triangular form) and then, as they progress, they are diverted to the direction of the axis of the canal. The damping reflected waves in the open sea are not so much affected, when the approximation is generalized from the first to the second one, expecting that the directivity of the damping reflected waves is smoothed. In developing the theory, a basic principle is based on themethod of the buffer domain which has been introduced by the author.筆者はすでに河口近傍における長波に関する研究をベッセル函数の線型近似の範囲でおこなつた.そしてその近似を第2次近似まで上げて解析をおこなつた結果をまとめたのが今回の報告である.その結果,第1近似ではわからなかつた河口近傍の波の細かい変化が判明してきた.新しくわかつたことは次のようなことである