Sound pressure generator

Abstract

A sound pressure generator includes a tube portion having a flow path extending in a tube axial direction; a rotor having a columnar shape with a column axis extending in a direction intersecting the tube axial direction in the flow path, the rotor configured to generate sound pressure by rotating about the column axis; and a drive unit configured to drive the rotor, wherein a cross-sectional shape of the rotor sectioned across the column axis includes a pointed first tip, a pointed second tip, and a long axis along which the first tip and the second tip are aligned.

1 . A sound pressure generator comprising:
 a tube portion having a flow path extending in a tube axial direction;   a rotor having a columnar shape with a column axis extending in a direction intersecting the tube axial direction in the flow path, the rotor configured to generate sound pressure by rotating about the column axis; and   a drive unit configured to drive the rotor,   wherein a cross-sectional shape of the rotor sectioned across the column axis includes a pointed first tip, a pointed second tip, and a long axis along which the first tip and the second tip are aligned.   
     
     
         2 . The sound pressure generator according to  claim 1 , wherein the cross-sectional shape is symmetric with respect to the long axis. 
     
     
         3 . The sound pressure generator according to  claim 1 , wherein, in the cross-sectional shape, the first tip and the second tip are curved and pointed. 
     
     
         4 . The sound pressure generator according to  claim 1 , wherein the cross-sectional shape is a shape in which the first tip and the second tip are connected by a pair of arcs. 
     
     
         5 . The sound pressure generator according to  claim 4 ,
 wherein the flow path has a duct diameter in a direction orthogonal to the column axis, and   the diameter of each arc of the pair of arcs is larger than the duct diameter.   
     
     
         6 . The sound pressure generator according to  claim 4 ,
 wherein the cross-sectional shape has a short axis orthogonal to the long axis, and   a ratio of the length of the short axis to the diameter of each arc of the pair of arcs is 40/49.6 or less.   
     
     
         7 . The sound pressure generator according to  claim 6 , wherein the ratio is 30/49.6 or less. 
     
     
         8 . The sound pressure generator according to  claim 7 , wherein the ratio is 20/49.6 or less. 
     
     
         9 . The sound pressure generator according to  claim 1 , wherein the cross-sectional shape is a shape where the first tip and the second tip are connected by a pair of first arcs extending from the first tip and a pair of second arcs extending from the second tip and a pair of parallel straight lines extending between the pair of first arcs and the pair of second arcs. 
     
     
         10 . The sound pressure generator according to  claim 9 , wherein the flow path has a duct diameter in a direction orthogonal to the column axis, and the diameter of each arc of the pair of first arcs and the pair of second arcs is larger than the duct diameter. 
     
     
         11 . The sound pressure generator according to  claim 9 , wherein the cross-sectional shape has a short axis orthogonal to the long axis, and a ratio of the length of the short axis to the diameter of each arc of the pair of first arcs and the pair of second arcs is 20/49.6 or less. 
     
     
         12 . The sound pressure generator according to  claim 11 , wherein the ratio is 15/49.6 or less. 
     
     
         13 . The sound pressure generator according to  claim 12 , wherein the ratio is 10/49.6 or less. 
     
     
         14 . The sound pressure generator according to  claim 13 , wherein the ratio is 5/49.6 or less. 
     
     
         15 . The sound pressure generator according to  claim 1 , wherein a cross-sectional area of the flow path having a section orthogonal to the tube axial direction and a cross-sectional area of the rotor having a section including the long axis and the column axis are substantially the same.