The velocity variation induced by the sinusoidal wall oscillation is measured along the stagnating streamline and its amplitude is estimated. The mechanisms of the flow velocity oscillation are discussed in terms of the amplitude of the flow velocity oscillation when the angular frequency of the wall oscillation w, the average distance between the nozzle and the wall ȳ. and the flow velocity at the nozzle exit Uo are varied. The characteristics of the flow velocity oscillation are classified into three regions by a Strouhal number S=w|ȳw/Uo. When S<2, the flow velocity variation follows the change of the wall location in a quasi-steady state. On the other hand, when S>6, it is dominated by the change of the wall velocity. In between, 2<S<6, the transition region is observed.
|ジャーナル||Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B|
|出版ステータス||Published - 1998|
ASJC Scopus subject areas