Abstract:
An air diverter fixedly positioned to the underside of the nose of an aircraft and forming an integral part therewith having a bull nose form for diverting the airflow around the nose of the aircraft thereby reducing the drag on the aircraft.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to reducing drag in aircraft and, more specifically, to a substantially laterally disposed bullnose-shaped airflow diverter located on the underside of the nose portion of an aircraft. The present invention is situated as such to redirect the concentrated airflow traveling along the nose away from the underside of the aircraft thereby enhancing the boundary layer control by reducing the viscous drag that would ordinarily be applied thereto and increasing the mechanical an economic integrity of the aircraft. 
     2. Description of the Prior Art 
     There are other means for reducing drag in aircraft. Typical of these is U.S. Pat. No. 2,727,706 issued to L. F. Hellig on Dec. 20, 1955. Another patent was issued to C. P. Baum on Sep. 23, 1969 as U.S. Pat. No. 3,468,501. Yet another U.S. Pat. No. 4,378,922 issued to D. Pierce on Apr. 5, 1983 and still yet another was issued on Dec. 3, 1991 to A. Wortman as U.S. Pat. No. 5,069,402. 
     In an airplane capable of subsonic and supersonic flight a member having a leading edge, said member having a permanent portion and a temporary portion of a predetermined variation in thickness defining a streamline contour, said portions when combined forming a relatively blunt leading edge of predetermined contour primarily suitable for subsonic flight, said permanent portion alone having a relatively sharp leading edge primarily for supersonic flight, said temporary portion being separable from said permanent portion as said airplane reaches supersonic speed. 
     A configuration to improve the aerodynamic and aerodynamic and structural efficiency of stores such as missiles, fuel tanks, etc., which are appended externally on high performance aircraft. By making the stores triangular in cross section, with a pointed nose and tail fins, and attaching them closely to an airframe, not only is air turbulence and drag reduced, but an added uplift is given to the aircraft by the action of the wedge shaped stores in causing an air compression area under the wing. 
     An aircraft has a series of strakes in the form of laterally projecting barbs (low aspect ratio semi-delta type aerofoils) extending longitudinally rearwards from and on each side of the nose, each barb lying substantially parallel to the longitudinal axis. 
     An aircraft having an upswept tail section fuselage includes a single pair of large vortex generators mounted in the vicinity of the break in the fuselage ahead of or at the beginning of the tail upsweep, each vortex generator being mounted on a side of and adjacent the bottom of the fuselage. The vortex generators, which may be plates or fins, develop strong transverse outflow from the vertical plane of symmetry that relieves or delays the tendency to flow separation by acting on the external flow field while at the same time energizing the boundary layer to increase its resistance to separation. The vortex generator may be thin or slightly thickened, flat or airfoil shaped, and may have triangular, straight, tapered, or reverse tapered platforms and may be rigid or flexible. Either one or both edges may be blunted, although sharp edges are preferred. 
     While these aircraft drag reduction means may be suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described. 
     SUMMARY OF THE PRESENT INVENTION 
     A primary object of the present invention is to provide an airflow diverter for aircraft to redirect the flowfield away from the underside of the fuselage as it travels downward from the nose portion thereof thereby reducing the viscous drag applied to said underside. 
     Another object of the present invention is to provide an airflow diverter for aircraft to improve the stability thereof by redirecting the flowfield equilaterally downward and to the sides of the fuselage. 
     Yet another object of the present invention is to provide an airflow diverter for aircraft that will increase the fuel economy thereof by reducing the drag applied thereto. 
     Still another object of the present invention is to provide an airflow diverter for aircraft that will provide improved resistance to sudden turbulence that may be encountered through wind shear and other such factors. 
     Yet another object of the present invention is to provide an airflow diverter for aircraft that is inexpensive to manufacture and operate. 
     One more object of the present invention is to provide an airflow diverter for aircraft that is simple and easy to use. 
     Additional objects of the present invention will appear as the description proceeds. 
     The present invention overcomes the shortcomings of the prior art by providing an airflow diverter for aircraft that will redirect the concentrated air flow initiated by the nose and redirect it to the sides and downward rather than allowing the concentrated air flow from traveling along the underside of the aircraft while also providing increased lift and stability when turbulence is encountered. 
     The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawing, which forms a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. In the accompanying drawing, like reference characters designate the same or similar parts throughout the several views. 
     LIST OF REFERENCE NUMERALS UTILIZED IN THE DRAWINGS 
       10  air diverter 
       12  aircraft 
       14  fuselage 
       16  aircraft nose 
       18  airflow field 
       20  boundary layer 
       22  air diverter housing 
       24  air diverted leading edge 
       26  air diverter top surface 
       28  air diverter bottom surface 
       30  air diverter first side 
       32  air diverter second side 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     In order that the invention may be more fully understood, it will now be described, by way of example, with reference to the accompanying drawing in which: 
     FIG. 1 is a side view of the prior art. 
     FIG. 2 is an illustrative view of the present invention installed on an aircraft. 
     FIG. 3 is a side view of the present invention installed diverting the airflow. 
     FIG. 4 is an enlarged view of the air diverter. 
     FIG. 5 is a front view of an aircraft having an air diverter. 
     FIG. 6 is an enlarged front view of the installed air diverter. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well. For a definition of the complete scope of the invention, the reader is directed to the appended claims. 
     FIG. 1 is a side view of an aircraft  12  of the prior art. Shown is a conventional airliner  12  with an exaggerated sectional depiction of the air movement  18  in the boundary layer  20  of the flowfield  18  as the air strikes the nose  16  of the fuselage  14  and is directed to flow along the underside thereof. The flowfield  18  is concentrated by the accumulation along the surface of the nose  16  and results in an increase of skin friction drag or viscous drag as the boundary layer  20  of the flowfield travels along the surface of the fuselage  14 . 
     Addressing drag reduction is critical to the aerospace industry since the typical energy loss due to viscous losses in a large transport aircraft such as the one illustrated could be as much as 40 per cent thereby penalizing the performance and the economics of the aircraft. 
     FIG. 2 is an illustrated view of the air diverter  10 . The present invention is designed for installation on aircraft  12  for the purpose of diverting initial nose  16  drag and reducing the ensuing viscous drag on the underside of the fuselage  14  as air flows therealong. Furthermore, the bullnose structure of the present invention  10  serves to act as a stabilizer fin so as to restrict the response of the nose  16  portion of the aircraft  12  when subjected to sudden turbulent conditions such as wind shear. 
     FIG. 3 is a side view of the air diverter  10  installed on an aircraft  12 . Shown is a conventional airliner  12  with an exaggerated sectional depiction of the air movement  18  in the boundary layer  20  of the flowfield as the air strikes the nose  16  of the fuselage  14  and is directed to flow along the underside thereof. The flowfield  18  is concentrated by the nose surface  16  and results in an increase of skin  14  friction drag or viscous drag as the boundary layer  20  of the flowfield travels along the surface of the fuselage  14 . 
     FIG. 4 is an enlarged view of the present invention  10  installed on an aircraft  12  where the air diverter leading edge  24  diverts the air  18  across the air diverter housing  22 . The bullnose configuration of the air diverter  10  provides aerofoil properties as the airflow  18  is directed sideways and downward by the air diverter housing  22  to help stabilize the nose portion  16  of the aircraft  12 . 
     FIG. 5 is a front view of the present invention  10  installed on an aircraft  12 . The present invention is a bullnose air flow diverter  10  for reducing viscous drag on the underside of the fuselage  14  of an aircraft  12  and stabilizing the nose  16  of the aircraft  12  when encountering sudden turbulent conditions. 
     FIG. 6 is a detailed front view of the present invention  10  installed on an aircraft  12 . Air flow  18  is diverted by the leading edge  24  of the air diverter  10  laterally and downward along air diverter housing  22  top surface  26 , bottom surface  28 , first side  30 , and second side  32  away from the boundary layer  20  of the flow field  18  on the underside  14  of the present invention  10 . The airflow diverter  10  also stabilizes the nose  16  of the aircraft  12  making it less responsive to shear conditions.