Abstract:
An apparatus and method for improving the fuel range of an aircraft are provided. The aircraft includes a fuselage with a front windshield, and an external skin providing a top cover for a cockpit of the aircraft. The apparatus includes an aerodynamic fairing secured adjacent the windshield and enclosing the external skin covering the cockpit for a reduction in an abrupt change in area encountered by air flowing along the length of the fuselage. An enclosure is formed between the aerodynamic fairing and the external skin in which a fuel bladder, configured with a reticulated polyurethane foam insert, may be disposed for added fuel capacity of the aircraft. The method includes steps of providing an aerodynamic fairing configured to balance the flow of fluid over the aircraft during flight, and securing the aerodynamic fairing atop the aircraft and adjacent the front windshield.

Description:
RELATED APPLICATION 
       [0001]    This application is a divisional of U.S. patent application Ser. No. 11/644,854 filed Dec. 22, 2006, entitled “Fuel Range For An Aircraft.” 
     
    
     FIELD THE INVENTION 
       [0002]    The claimed invention relates generally to the field of aviation and more particularly, but not by way of limitation, to a method and apparatus for improved fuel capacity for an aircraft to increase range. 
       BACKGROUND 
       [0003]    The optimization of fluid flow over an aircraft is an important task typically undertaken by aeronautical engineers during the development and testing phases involved in bringing an aircraft to market. Balancing the air flow over the aircraft reduces drag encountered by aircraft during flight, which reduces fuel consumption of the aircraft across a range of flight speeds of the aircraft, thereby increasing the range of the aircraft for a specific fuel capacity. A reduction in drag encountered by the aircraft during flight also permits attainment of greater in flight speeds of the aircraft. In either case, the ratio of fuel consumption to airspeed decreases with the reduction of drag. 
         [0004]    Most commercial and private aircraft in service today were developed during times of “cheap” fuel, when the focus of development teams were predominantly devoted to the maximization of passenger payload the aircraft could carry, and the ease of manufacturing the airframe. Recently, aircraft engine development teams have been developing higher efficiency, cleaner burning engines, which improve the overall energy efficiency of aircraft, and airframe development teams have been working on reducing drag encountered by the wings. However, a source of drag that remains for the vast majority of in-service transonic, i.e., flight speed greater than Mach 0.7 aircraft is drag encountered by the aircraft during flight as a result of air flowing over the front windshield, and abruptly encountering the main body portion of the fuselage. 
         [0005]    Accordingly, there is a long felt need for methods and apparatus for reducing the effects of windshield induced drag, and improving the fuel range for an aircraft operating within the operating limits prescribed for the aircraft. 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with a preferred embodiment, an aircraft includes at least a fuselage providing a front windshield, and an external skin adjacent the windshield, wherein the external skin covers a top portion of a cockpit of the aircraft, and an aerodynamic fairing secured adjacent the windshield and enclosing the external skin covering the cockpit to form an enclosed volume. 
         [0007]    In accordance with a preferred embodiment, the aerodynamic fairing is configured to balance the flow of air flowing across the aircraft during flight by improving the distribution of the area along the fuselage axis, which reduces drag encountered by the aircraft during flight. The fuselage preferably further providing a condensate relief channel disposed between the aerodynamic fairing and the external skin covering the cockpit. The condensate relief channel provides a channel for relief of any condensate formed within the enclosed volume, and the aerodynamic faring is preferably formed from materials such as aluminum, carbon fiber composite, fiberglass composite, and metal matrix composites. 
         [0008]    In an alternate preferred embodiment, the space created between the aerodynamic faring and the external skin covering the cockpit, i.e., the enclosed volume, is used for the inclusion of a fuel bladder, which is disposed between the aerodynamic fairing and the external skin covering the cockpit. The fuel bladder provides additional fuel carrying capacity for the aircraft, which extends the flight range for the aircraft. 
         [0009]    To gain access to the fuel bladder, a fuel port supported by the aerodynamic fairing is included, and is fitted to provide access to the interior portion of the fuel bladder, for filling the bladder with fuel. The fuel port further mitigates escapement of the fuel from the bladder. Preferably, the fuel bladder is configured with a reticulated polyurethane foam insert enveloped by the fuel bladder. The reticulated polyurethane foam insert is included for fire/explosion suppression of the fuel. 
         [0010]    In an alternative preferred embodiment, a method of improving fuel range preferably includes, providing an aerodynamic fairing configured to balance the flow of air over an aircraft during flight, thereby reducing drag encountered by said aircraft during flight; and securing the aerodynamic fairing atop the aircraft and adjacent a front windshield of the aircraft. In a preferred embodiment, the aerodynamic fairing in cooperation with an external skin covering the cockpit of the aircraft forms the enclosed volume. Due to changes in altitude encountered by the aircraft during flight, condensate frequently forms within the enclosed volume created between the aerodynamic faring and the external skin. Accordingly, the method of improving fuel range preferably further includes, forming a condensate relief channel disposed between the aerodynamic fairing and the external skin for relief of condensate formed between said aerodynamic fairing and said external skin. 
         [0011]    In a preferred embodiment, the volume created between the aerodynamic faring and the external skin is utilized for the inclusion of additional fuel, therefore, the method preferably further includes, incorporating a fuel port in a top portion of the aerodynamic fairing, mounting a fuel bladder within the enclosed volume and fitting the fuel port to an interior portion of the fuel bladder, such that the fuel port provides access to the fuel bladder for supply of a fuel, while mitigating escapement of the fuel from the fuel bladder. The preferred embodiment further includes a step of disposing a reticulated polyurethane foam insert within the fuel bladder; the reticulated polyurethane foam insert is included for purposes of fire/explosion suppression of the fuel. 
         [0012]    These and various other features and advantages, which characterize preferred embodiments of the present invention, will be apparent from reading the following detailed description in conjunction with reviewing the associated drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a top plan view of prior art aircraft found useful in applying the present invention. 
           [0014]      FIG. 2  provides an in flight side elevation view of the prior art aircraft of  FIG. 1 . 
           [0015]      FIG. 3  provides a front elevation view of the prior art aircraft of  FIG. 1 . 
           [0016]      FIG. 4  is a top plan view of an aircraft of the present invention. 
           [0017]      FIG. 5  provides an in flight side elevation view of the aircraft of  FIG. 4 . 
           [0018]      FIG. 6  provides a front elevation view of the aircraft of  FIG. 4 . 
           [0019]      FIG. 7  shows a partial cut-away, side elevation view of the aircraft of  FIG. 4 , showing an aerodynamic fairing in partial cut-away. 
           [0020]      FIG. 8  is a diagram of a flowchart of a method of making the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    Reference will now be made in detail to one or more examples of the invention depicted in the accompanying figures. Each example is provided by way of explanation of the invention, and is not meant as, nor do they represent, limitations imposed upon the invention. For example, features illustrated or described as part of one embodiment may be used with another embodiment to yield still a different embodiment. Other modifications and variations to the described embodiments are also contemplated and lie within the scope and spirit of the invention. 
         [0022]    Referring to the drawings, to provide an enhanced understanding of the present invention, a reader is encouraged to view prior art  FIGS. 1 ,  2 , and  3  in concert while proceeding with reading this description of the present invention. Collectively, prior art  FIGS. 1 ,  2 , and  3  depict aircraft applicable for use in forming the present invention. 
         [0023]    Prior art  FIG. 1  presents a plan view a prior art aircraft  10  found useful in practicing the present invention. Prior art  FIG. 2  shows the prior art aircraft  10  in an in flight elevation view, and  FIG. 3  shows a front view of prior art aircraft  10 . When collectively viewing prior art  FIGS. 1 ,  2 , and  3 , the reader&#39;s attention is drawn to the location of a nose portion  12  of a fuselage  14 , a front windshield  16 , and a portion of the fuselage skin  18  adjacent the windshield  16  and covering a cockpit  20  of the prior art aircraft  10 . 
         [0024]    The prior art aircraft  10 , of  FIG. 2 , depicts an air flow path  22  (shown by dashed lines) taken by air passing across an underside  24  of the prior art aircraft  10  during flight, and an air flow path  26  (shown by dashed lines) taken by air passing across a top of the nose portion  12 , the front windshield  16 , and the fuselage skin  18  covering the cockpit  20 , i.e., the path taken by air passing across the top side of the prior art aircraft  10 . 
         [0025]    As those skilled in the art will recognize, as the air flows encounters the nose and windshield  16  and flows over the length of the fuselage the air flow encounters an abrupt change in area. This abrupt change in area imparts additional drag on the prior art aircraft  10 , which equates to a higher burn rate of fuel during flight of the prior art aircraft  10 . This increased drag generally in the region indicated by sign number  28  located substantially above the cockpit  20 . 
         [0026]      FIG. 4  shows a top plan view of an inventive aircraft  100  depicting an aerodynamic fairing  102 , and a pair of condensate relief channels  104 . It will be noted that the aerodynamic faring  102  has a “teardrop” shape and contour, and that the pair of condensate relief channels  104  are located at the lowest point of interaction between the aerodynamic fairing  102  and a skin  106  of fuselage  108 . 
         [0027]    The present inventive aircraft  100 , of  FIG. 5 , depicts an air flow path  110  (shown by dashed lines) taken by air passing across the underside  112  of the present inventive aircraft  100  during flight, and an air flow path  114  (shown by dashed lines) taken by air passing across a top portion of a nose portion  116 , a front windshield  118 , and the aerodynamic fairing  102 , i.e., the path taken by air passing across the top side of the present inventive aircraft  100 . It will be noted that in a preferred embodiment, the aerodynamic fairing  102  covers an external skin portion  120  of the skin  106  that envelopes the fuselage  108 . In particular, the external skin portion  120  covers a top of a cockpit  122  of the present inventive aircraft  100 , which is enclosed by the external skin portion  120 . 
         [0028]    As those skilled in the art will recognize, as the air flow encounters and subsequently flows over the windshield  118 , the air flow encounters an abrupt change in area along the length of the fuselage. The inclusion of the aerodynamic fairing  102  reduces the abruptness and therefore reduces the amount of drag encountered by the inventive aircraft  100 . 
         [0029]    The mitigation of the abruptness encountered by the air flow passing over the length of the fuselage of the present inventive aircraft  100  during flight, results in an attainment of a reduced rate of fuel burn at any given speed at which the present inventive aircraft  100  is traveling, thereby improving the fuel range for the present inventive aircraft  100 . Those skilled in the art will also recognize that a reduction in drag encountered by the present inventive aircraft  100  during flight, also equates to an ability of the present inventive aircraft  100  to attain higher rates of speed during flight. 
         [0030]      FIG. 5  further shows that the aerodynamic faring  102  provides some what of a continuum of the slope of the windshield  118 , which then crests and provides a smooth roll off transition back to the skin  106  that envelopes the fuselage  108 , while  FIG. 6  shows the face of the aerodynamic fairing  102  to have a smooth, rounded, almost bullet like contour; a shape known to those skilled in the art for its ability to minimize an abrupt change in area encountered by the air stream. Also shown by  FIG. 5  is an enclosed volume  124 , which is formed between the aerodynamic fairing  102  and the external skin portion  120  when the aerodynamic fairing  102  is attached adjacent the windshield  118  and to the external skin portion  120  of the fuselage  108 . 
         [0031]    In a preferred embodiment, the condensate relief channels  104  provide a channel for relief of condensate formed within the enclosed volume  124  via changes in altitude encountered by the present inventive aircraft  100  during normal flight operations. Additionally, the aerodynamic fairing  102  is preferably formed from materials such as aluminum, a carbon fiber composite, a fiberglass composite, and metal matrix composites.  FIG. 5  additionally shows that in a preferred embodiment, the windshield  118  is configured such that at least a portion of the windshield  118  extends beneath the fairing  102 , and in which the external skin portion  120  covering the cockpit blocks at least a portion of a field of view above the head of a pilot flying the aircraft. 
         [0032]      FIG. 7  depicts an alternate preferred embodiment of the present inventive aircraft  100 . In the alternate preferred embodiment, the enclosed volume  124  (of  FIG. 5 ) is fitted with a fuel bladder  126  (shown in partial cut-away), which provides a reticulated polyurethane foam insert  128  (also shown in partial cut-away), enveloped by the fuel bladder  126 . The reticulated polyurethane foam insert  128  is included as an explosion suppression for fuel contained within the fuel bladder  126 .  FIG. 7  further shows a fuel port  130  is supported by the aerodynamic fairing  102 . The fuel port  130  is fitted to the fuel bladder such that an interior of the fuel bladder  126  is made accessible for the supply of fuel to the fuel bladder  126 . That is, the fuel port  130  provides access to the fuel bladder  126 , and mitigates escapement of fuel from said fuel bladder  126 . 
         [0033]    Turning to  FIG. 8 , the flow chart  200  depicts a process of forming an inventive aircraft (such as  100 ). It will be understood that the steps of the process described herein below need not be performed in the order presented, and that the sequence of the process steps as presented herein below does not impose any limitations on the present invention. 
         [0034]    Accordingly, the method commences at start process step  202 , and proceeds to process step  204 , with the provision of an aerodynamic fairing (such as  102 ). At process step  206 , the aerodynamic fairing is secured atop the inventive aircraft to form an enclosed volume (such as  124 ). The aerodynamic fairing is secured adjacent a front windshield (such as  118 ), and above an external skin portion (such as  120 ) covering a cockpit (such as  122 ) of the inventive aircraft. 
         [0035]    At process step  208 , a condensate relief channel (such as  104 ) is formed between the aerodynamic fairing and the external skin. At process step  210 , a fuel port (such as  130 ) is incorporated within the aerodynamic fairing, and at process step  212 , a fuel bladder (such as  126 ) is mounted within the enclosed volume, and an interior of the fuel bladder is fitted to the fuel port, such that fuel port provides access to the fuel bladder for supply of a fuel, and mitigates escapement of the fuel from said fuel bladder. 
         [0036]    At process step  214 , a reticulated polyurethane foam insert (such as  128 ) is disposed within the fuel bladder, and the process concludes at end process step  216 . 
         [0037]    It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and function thereof, this detailed description is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. For example, the particular elements may vary depending on the particular application for a select engine, while maintaining the same functionality without departing from the spirit and scope of the invention.