Airfoil for fan blade

Abstract

A fan blade comprises an airfoil profile having a lower surface, an upper surface, a trailing edge, and a leading edge. The lower surface comprises a concave portion which is defined by a first ellipse. The upper surface comprises a convex portion which is defined by a second ellipse. The leading edge and the trailing edge are of a substantially convex shape and transition the concave shape of the lower surface to the convex shape of the upper surface. A maximum thickness of the airfoil profile is defined at a point along the airfoil profile proximal to the leading edge of the fan blade. A chord length is defined as a lineal distance between an outermost point of the leading edge and an outermost point of the trailing edge. The dimensions of the airfoil profile, including those of the first ellipse and second ellipse, are functions of the chord length.

1 .- 8 . (canceled) 
     
     
         9 . A fan blade configured to mount to a rotating fan hub, the fan blade comprising an airfoil profile, the airfoil profile comprising:
 a. a lower surface, wherein the lower surface comprises a concave portion extending between a first point and a second point, and wherein a maximum thickness of the airfoil profile is defined at the first point along the airfoil profile;   b. an upper surface, wherein the upper surface comprises a convex portion extending between a third point and a fourth point;   c. a leading edge, wherein the leading edge is of a substantially convex shape, and wherein the leading edge extends between the first point of the lower surface and the third point of the upper surface;   d. a trailing edge, wherein the trailing edge is of a substantially convex shape, and wherein the trailing edge extends between the second point of the lower surface and the fourth point of the upper surface; and   e. a chord length (c), wherein the chord length is defined by a lineal distance from an outermost point of the leading edge to an outermost point of the trailing edge.   
     
     
         10 . The fan blade of  claim 9 , wherein a radius of the substantially convex shape of the leading edge varies from the first point of the lower surface to the third point of the upper surface. 
     
     
         11 . The fan blade of  claim 9 , wherein the first point is located a distance of about 0.724 c away from the trailing edge of the air foil profile and along the chord length. 
     
     
         12 . The fan blade of  claim 9 , wherein the third point is located a distance of about 0.776 c away from the trailing edge of the air foil profile and along the chord length. 
     
     
         13 . The fan blade of  claim 9 , wherein a portion of the leading edge surrounding the outermost point of the leading edge has a radius of about 0.06 c. 
     
     
         14 . The fan blade of  claim 9 , wherein a radius of the substantially convex shape of the trailing edge varies from the second point of the lower surface to the fourth point of the upper surface. 
     
     
         15 . The fan blade of  claim 9 , wherein the second point is located a distance of about 0.015 c away from the trailing edge of the air foil profile and along the chord length. 
     
     
         16 . The fan blade of  claim 9 , wherein the fourth point is located a distance of about 0.006 c away from the trailing edge of the air foil profile and along the chord length. 
     
     
         17 . The fan blade of  claim 9 , wherein a portion of the trailing edge surrounding the outermost point of the leading edge has a radius of about 0.011 c. 
     
     
         18 . The fan blade of  claim 9 , wherein the maximum thickness of the airfoil profile is about 0.157 c. 
     
     
         19 . The fan blade of  claim 9 , wherein the concave portion of the lower surface is defined by a first ellipse and wherein the convex portion of the upper surface is defined by a second ellipse. 
     
     
         20 . The fan blade of  claim 19 , wherein the first ellipse comprises a major axis having a length of about 1.725 c and a minor axis having a length of about 0.5 c. 
     
     
         21 . The fan blade of  claim 20 , wherein concave portion of the lower surface is defined by an arcuate segment of the first ellipse such that the major axis of the first ellipse and the chord of the airfoil profile form an angle of about 11 degrees. 
     
     
         22 . The fan blade of  claim 19 , wherein the second ellipse comprises a major axis having a length of about 1.843 c and a minor axis having a length of about 0.583 c. 
     
     
         23 . The fan blade of  claim 22 , wherein the convex portion of the upper surface is defined by an arcuate segment of the second ellipse such that the major axis of the second ellipse and the chord length of the airfoil profile form an angle of about 17 degrees. 
     
     
         24 . The fan blade of  claim 9 , wherein a length defined by the lower surface of the airfoil profile from the outermost point of the leading edge to the outermost point of the trailing edge is about 1.033 c. 
     
     
         25 . The fan blade of  claim 9 , wherein a length defined by the upper surface of the airfoil profile from the outermost point of the leading edge to the outermost point of the trailing edge is about 1.073 c. 
     
     
         26 . A fan assembly, wherein the fan assembly comprises:
 a. a fan motor;   b. a fan hub, wherein the fan hub is coupled to the fan motor; and   c. a plurality of fan blades, wherein each fan blade of the plurality of fan blades comprises the fan blade of  claim 9 .   
     
     
         27 . A fan blade, wherein the fan blade comprises an airfoil profile, the airfoil profile comprising:
 a. a lower surface, wherein the lower surface comprises a concave portion extending between a first point and a second point, wherein the concave portion of the lower surface is defined by a first ellipse, and wherein a maximum thickness of the airfoil profile is defined at the first point along the airfoil profile;   b. an upper surface, wherein the upper surface comprises a convex portion extending between a third point and a fourth point, and wherein the convex portion of the upper surface is defined by a second ellipse;   c. a leading edge, wherein the leading edge is of a substantially convex shape, wherein the leading edge extends between the first point of the lower surface and the third point of the upper surface, and wherein a radius of the substantially convex shape of the leading edge varies from the first point of the lower surface to the third point of the upper surface; and   d. a trailing edge, wherein the trailing edge is of a substantially convex shape, wherein the trailing edge extends between the second point of the lower surface and the fourth point of the upper surface, and wherein a radius of the substantially convex shape of the trailing edge varies from the second point of the lower surface to the fourth point of the upper surface.   
     
     
         28 . A fan assembly, wherein the fan assembly comprises:
 a. a fan motor;   b. a fan hub, wherein the fan hub is couple to the fan motor; and   c. a plurality of fan blades, wherein each one of the fan blades of the plurality of fan blades defines an airfoil profile, wherein each one of the fan blades of the plurality of fan blades comprises;
 i. a lower surface, wherein the lower surface comprises a concave portion extending between a first point and a second point, wherein the concave portion of the lower surface is defined by a first ellipse, and wherein a maximum thickness of the airfoil profile is defined at the first point along the airfoil profile, 
 ii. an upper surface, wherein the upper surface comprises a convex portion extending between a third point and a fourth point, and wherein the convex portion of the upper surface is defined by a second ellipse, 
 iii. a leading edge, wherein the leading edge is of a substantially convex shape, wherein the leading edge extends between the first point of the lower surface and the third point of the upper surface, and wherein a radius of the substantially convex shape of the leading edge varies from the first point of the lower surface to the third point of the upper surface, and 
 iv. a trailing edge, wherein the trailing edge is of a substantially convex shape, wherein the trailing edge extends between the second point of the lower surface and the fourth point of the upper surface, and wherein a radius of the substantially convex shape of the trailing edge varies from the second point of the lower surface to the fourth point of the upper surface.