Blade body and rotary machine

Abstract

The blade body of the present invention is provided with a main body which has a dorsal face and a ventral face and also provided with a trailing edge portion which connects the dorsal face to the ventral face with a continuous curved face. The curved face of the trailing edge portion is gradually decreased in curvature radius from one of the dorsal face and the ventral face toward the rear end portion which is positioned most downstream in a direction at which a fluid flows, decreased to the greatest extent in curvature radius at the rear end portion, thereafter, gradually increased in curvature radius from the rear end portion toward the other of the dorsal face and the ventral face and arrives at the other of the dorsal face and the ventral face.

1 . A blade body comprising:
 a main body which has a dorsal face and a ventral face; and   a trailing edge portion which connects the dorsal face to the ventral face with a continuous curved face; wherein   a curved face of the trailing edge portion is gradually decreased in curvature radius from one of the dorsal face and the ventral face toward a rear end portion which is positioned most downstream in a direction at Which a fluid flows, decreased to the greatest extent in curvature radius at the rear end portion, and wherein   the curved face of the trailing edge portion is gradually increased in curvature radius from the rear end portion toward the other of the dorsal face and the ventral face and arrives at the other of the dorsal face and the ventral face.   
     
     
         2 . The body according to  claim 1 , wherein
 the trailing edge portion is such that the changing of the curvature radius of a part of the curved face positioned at the dorsal face side which decreases as close to the rear end portion is different from the changing of the curvature radius the other part of the curved face positioned at the ventral face side which decreases as close to the rear end portion.   
     
     
         3 . The body according to  claim 1 , wherein
 the rear end portion is disposed on an extended line of a camber line of the main body.   
     
     
         4 . The body according to  claim 1 , wherein
 the rear end portion is disposed further to the side of the dorsal face or to the side of the ventral face than the extended line of the camber line of the main body.   
     
     
         5 . A plurality of blade bodies which are disposed on a rotary body at an equal interval,
 and the blade body according to  claim 1 , wherein   the curved face of the trailing edge portion is formed so as to have a curvature radius capable of maintaining a throat between blades where no trailing edge portion is provided.   
     
     
         6 . A rotary machine which is provided with the blade body according to  claim 1 .