音波による噴流構造の制御 : 第2報,スペクトル分布と速度場の流れ方向変化について

抄録

A plane jet was acoustically excited at its symmetrical and anti-symmetrical excitation frequencies. Effects of the excitation were elucidated by measuring spectral profiles. Velocity vector plots were also obtained around the jet to distinguish the difference in the flow pattern due to the excitation modes. When the jet was acoustically excited, it demonstrated clearer symmetrical or anti-symmetrical eddy arrangement than a natural jet without excitation. The symmetrical eddy arrangement in the linear interaction region of the symmetrically excited jet was not quite stable and began to make flapping motions in its non-linear interaction region. When the sound wave of the anti-symmetrical mode was introduced, the jet demonstrated an eddy arrangement with largest scales and most rigid construction in the non-linear interaction region, and its width was observed to spread outward most rapidly as it flowed downstream.