High efficiency fan blades with airflow-directing baffle elements

Abstract

Fan blades are provided that increase aerodynamic and operational efficiency, and which include baffle elements positioned on the distal ends of the fan blades. The baffle elements operate by shearing blade tip vortices, thereby minimizing turbulent fluid effects, and further providing fluid shunt that imparts a radial velocity component to the fluid. The baffle elements produce a more focused and collimated fluid flow perpendicular to the plane of rotation during forward rotation, and produce a more diffuse, radially-outward directed fluid flow during reverse rotation. The baffle elements are positioned such that they are characterized by a first angle with respect to the radial axis of the fan blade and a second angle with respect to the low pressure surface of the fan blade.

1 . A fan blade comprising:
 a blade body including a leading edge, a trailing edge, a proximal end, a distal end, a high pressure surface, a low pressure surface, and a radial axis; and   at least one baffle element positioned on the blade body at a first angle with respect to the radial axis and at a second angle with respect to the low pressure surface.   
   
   
       2 . The fan blade of  claim 1 , further comprising a plurality of baffle elements positioned on the blade body at a first angle with respect to the radial axis and at a second angle with respect to the low pressure surface. 
   
   
       3 . The fan blade of  claim 1 , wherein the at least one baffle element is positioned on the distal end. 
   
   
       4 . The fan blade of  claim 1 , wherein the first angle with respect to the radial axis is in the range of approximately 30-degrees to approximately 60-degrees. 
   
   
       5 . The fan blade of  claim 1 , wherein the first angle with respect to the radial axis is approximately 45-degrees. 
   
   
       6 . The fan blade of  claim 1 , wherein the at least one baffle element extends from the low pressure surface. 
   
   
       7 . The fan blade of  claim 1 , wherein the second angle with respect to the low pressure surface is approximately 90-degrees. 
   
   
       8 . The fan blade of  claim 1 , wherein the at least one baffle element extends from both the low pressure surface and the high pressure surface. 
   
   
       9 . The fan blade of  claim 8 , wherein the second angle with respect to the low pressure surface is approximately 90-degrees, and a third angle between the baffle element and the high pressure surface is approximately 90-degrees. 
   
   
       10 . The fan blade of  claim 1 , wherein the at least one baffle element extends from the high pressure surface. 
   
   
       11 . The fan blade of  claim 1 , wherein the second angle with respect to the low pressure surface is approximately 270-degrees. 
   
   
       12 . The fan blade of  claim 1 , wherein the at least one baffle element is configured to be removably attached to the blade body. 
   
   
       13 . The fan blade of  claim 1 , wherein the blade is utilized in an assembly comprising a plurality of fan blades. 
   
   
       14 . A fan blade comprising:
 a blade body including a leading edge, a trailing edge, a proximal end, a distal end, a high pressure surface, a low pressure surface, and a radial axis; and   at least one baffle element positioned on the distal end of the blade body at a first angle of approximately 45-degrees with respect to the radial axis and extending from the low pressure surface at a second angle of approximately 90-degrees with respect to the low pressure surface.   
   
   
       15 . A fan blade comprising:
 a blade body including a leading edge, a trailing edge, a proximal end, a distal end, a high pressure surface, a low pressure surface, and a radial axis; and   a plurality of baffle elements each positioned on the blade body at a first angle with respect to the radial axis and at a second angle with respect to the low pressure surface.   
   
   
       16 . An fan comprising:
 a hub;   a plurality of blades, each blade comprising a leading edge, a trailing edge, a proximal end, a distal end, a high pressure surface, a low pressure surface, and a radial axis, and each blade attached to the hub at the proximal end and positioned such that the distal end projects in a substantially radial direction away from the hub along the radial axis; and   a plurality of baffle elements attached to the plurality of blades and positioned at a first angle with respect to the radial axis and at a second angle with respect to the low pressure surface.   
   
   
       17 . The fan of  claim 16 , wherein the baffle elements are positioned on the distal ends of the fan blades. 
   
   
       18 . The fan of  claim 16 , wherein the baffle elements are attached to the low pressure surfaces of the blades. 
   
   
       19 . The fan of  claim 16 , wherein the first angle with respect to the radial axis is approximately 45-degrees and the second angle with respect to the low pressure surface is approximately 90-degrees. 
   
   
       20 . A baffle element configured to be retrofit to a fan blade, the fan blade comprising a leading edge, a trailing edge, a proximal end, a distal end, a high pressure surface, a low pressure surface, and a radial axis, wherein the baffle element is configured to be positioned on the fan blade at a first angle with respect to the radial axis and at a second angle with respect to the low pressure surface.