Abstract: In a method of deriving the buckling condition of a cylindrical fiber moving in a fluid, a method of calculating the breakage condition thereof, and a method of forecasting the fiber length distribution, the flow field around a cylindrical fiber in a contraction flow is determined by a stricter method.

Abstract: A piezoelectric fan is provided that can effectively supply airflow to a subject to be cooled. The piezoelectric fan includes an air blower having a free end and a fixed end, and a planar piezoelectric element fixed to the air blower. The piezoelectric element causes vibration of the free end of the air blower. The air blower includes a first plate to which the piezoelectric element is fixed, and a second plate and a third plate which are orthogonal to the first plate and parallel to each other. In this structure, the free end of the air blower is H-shaped. The H-shaped blowing end of the air blower effectively prevents lateral airflow and improves the directivity of airflow.

Abstract: A piezoelectric fan is provided that can effectively supply airflow to a subject to be cooled. The piezoelectric fan includes an air blower having a free end and a fixed end, and a planar piezoelectric element fixed to the air blower. The piezoelectric element causes vibration of the free end of the air blower. The air blower includes a first plate to which the piezoelectric element is fixed, and a second plate and a third plate which are orthogonal to the first plate and parallel to each other. In this structure, the free end of the air blower is H-shaped. The H-shaped blowing end of the air blower effectively prevents lateral airflow and improves the directivity of airflow.