Fan blade design

Abstract

The novel fan blade functions by capturing the air mass via an upper, larger airfoil with a lower, smaller chord airfoil arrangement that channels air through the slot between the larger and smaller airfoil that are both twisted along the span of the blade. This design generates air movement more effectively and achieves significantly better performance than a traditional fan blade design.

1 . A novel blade design comprising:
 a primary airfoil having a root for connecting to a rotating hub, a tip opposite the root, a leading edge, and a trailing edge, wherein the primary airfoil has an angle of incidence relative to the plane of rotation of the primary airfoil of between about 3° and 25°;   a secondary airfoil generally parallel to the primary airfoil having a root generally proximate the root of the primary airfoil, a tip opposite the root and generally proximate the tip or the primary airfoil, a leading edge, and a trailing edge, wherein the secondary airfoil is disposed below and aft of the primary airfoil so as to create a spanwise gap for passage of high pressure air from the lower surface of the primary airfoil to flow through the gap and re-energize the airflow along the upper surface of the secondary airfoil, resulting in attached flow and increased re-direction of the flow in the axial direction;   wherein the secondary airfoil is connected proximate the trailing edge of the primary airfoil through a plurality of vertical support fins and wherein the secondary airfoil has an angle of incidence relative to the plane of rotation of the blade secondary airfoil of between about 5° and 40°; and   the plurality of vertical support fins connected to the bottom of the primary airfoil at the top of the vertical support fins and connected to the top of the secondary airfoil at the bottom of the vertical support fins.   
     
     
         2 . The novel blade design of  claim 1 , wherein the primary airfoil includes a twist to provide a lower angle of incidence towards the tip. 
     
     
         3 . The novel blade design of  claim 2 , wherein the angle of incidence of the primary airfoil proximate the root is between about 100 and 30°. 
     
     
         4 . The novel blade design of  claim 2 , wherein the angle of incidence of the primary airfoil proximate the tip is between about 3° and 8°. 
     
     
         5 . The novel blade design of  claim 2 , wherein the angle of incidence of the secondary airfoil proximate the root is between about 20° and 40°. 
     
     
         6 . The novel blade design of  claim 2 , wherein the angle of incidence of the secondary airfoil proximate the tip is between about 8° and 20°. 
     
     
         7 . The novel blade design of  claim 1 , wherein said primary airfoil and said secondary airfoil are each rigidly affixed to a rotating hub. 
     
     
         8 . The novel blade design of  claim 1 , wherein said primary airfoil and said secondary airfoil are each rotatably affixed to a rotating hub. 
     
     
         9 . The novel blade design of  claim 3 , wherein the angle of incidence of each of said primary airfoil and said secondary airfoil variable. 
     
     
         10 . A novel fan blade design comprising:
 a primary airfoil having a root for connecting to a rotating hub connected to a fan motor, a tip opposite the root, a leading edge, and a trailing edge, wherein the primary airfoil has an angle of incidence relative to the plane of rotation of the blade primary airfoil of between about 3° and 25°;   a secondary airfoil generally parallel to the primary airfoil having a root generally proximate the root of the primary airfoil, a tip opposite the root and generally proximate the tip or the primary airfoil, a leading edge, and a trailing edge, wherein the secondary airfoil is disposed below and aft of the primary airfoil so as to create a spanwise gap for passage of high pressure air from the lower surface of the primary airfoil to flow through the gap and re-energize the airflow along the upper surface of the secondary airfoil, resulting in attached flow and increased re-direction of the flow in the axial direction;   wherein the secondary airfoil is connected proximate the trailing edge of the primary airfoil through a plurality of vertical support fins and wherein the secondary airfoil has an angle of incidence relative to the plane of rotation of the secondary airfoil of between about 5° and 40°; and   the plurality of vertical support fins connected to the bottom of the primary airfoil at the top of the vertical support fins and connected to the top of the secondary airfoil at the bottom of the vertical support fins.   
     
     
         11 . The novel blade design of  claim 10 , wherein the primary airfoil includes a twist to provide a lower angle of incidence towards the tip. 
     
     
         12 . The novel blade design of  claim 11 , wherein the angle of incidence of the primary airfoil proximate the root is between about 10° and 30°. 
     
     
         13 . The novel blade design of  claim 11 , wherein the angle of incidence of the primary airfoil proximate the tip is between about 3° and 8°. 
     
     
         14 . The novel blade design of  claim 11 , wherein the angle of incidence of the secondary airfoil proximate the root is between about 20° and 40°. 
     
     
         15 . The novel blade design of  claim 11 , wherein the angle of incidence of the secondary airfoil proximate the tip is between about 8° and 20°. 
     
     
         16 . A novel fan blade design comprising:
 a primary airfoil having a root for connecting to a rotating hub connected to a fan motor, a tip opposite the root, a leading edge, and a trailing edge, wherein the primary airfoil has an angle of incidence relative to the plane of rotation of the primary airfoil of between about 3.5° and 15°;   a secondary airfoil generally parallel to the primary airfoil having a root generally proximate the root of the primary airfoil, a tip opposite the root and generally proximate the tip or the primary airfoil, a leading edge, and a trailing edge, wherein the secondary airfoil is disposed below and aft of the primary airfoil so as to create a spanwise gap for passage of high pressure air from the lower surface of the primary airfoil to flow through the gap and re-energize the airflow along the upper surface of the secondary airfoil, resulting in attached flow and increased re-direction of the flow in the axial direction;   wherein the secondary airfoil is connected proximate the trailing edge of the primary airfoil through a plurality of vertical support fins and wherein the secondary airfoil has an angle of incidence relative to the plane of rotation of the blade secondary airfoil of between about 13° and 35°; and   the plurality of vertical support fins connected to the bottom of the primary airfoil at the top of the vertical support fins and connected to the top of the secondary airfoil at the bottom of the vertical support fins.   
     
     
         17 . The novel blade design of  claim 16 , wherein the angle of incidence of the primary airfoil proximate the root is between about 10° and 12°. 
     
     
         18 . The novel blade design of  claim 16 , wherein the angle of incidence of the primary airfoil proximate the tip is between about 4° and 6°. 
     
     
         19 . The novel blade design of  claim 16 , wherein the angle of incidence of the secondary airfoil proximate the root is between about 16° and 30°. 
     
     
         20 . The novel blade design of  claim 16 , wherein the angle of incidence of the secondary airfoil proximate the tip is between about 15° and 18°.