Abstract:
A fairing system developed to reduce the flow disturbance around sensor elements allowing accurate measurement of the pressure distribution on an object surface. The fairing also protects the sensors and electronics of the pressure belt from direct exposure to airflow.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of application Ser. No. 11/078,984, filed on Mar. 11, 2005, the entire contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present embodiments relate generally to a fairing system developed to reduce the flow disturbance around sensor elements allowing accurate measurement of the pressure distribution on an airplane exterior surface. 
         [0004]    2. Related Art 
         [0005]    The ability to measure the pressure distribution across an airplane external surface is a requirement for Flight Test. To measure pressure distribution, tubing has been glued to the external surface and plumbed to pressure sensors positioned in a remote location. This solution has proved to be labor intensive, expensive to install and troublesome to maintain. 
         [0006]    A sensor pressure belt has been developed which locates the sensor at the required measurement location. For example, in U.S. Pat. No. 6,134,485, a system and method for analyzing physical parameters of flight data is described, which includes a multi-sensor system having an array of belts. Each belt includes a plurality of interconnected belt segments including a substrate having an electrically conductive digital data bus, and at least one module having a first sensor, a second sensor and a digital signal processor and a coating for protecting the belt segment. The first and second sensors, which are preferably formed as micro-electromechanical sensors sharing a common substrate, respectively generate signals representative of a first physical parameter and a second physical parameter. The processor receives and analyzes the first and second signals to generate a third signal. The third signal is transmitted along the electrically-conductive bus to a remotely-located controller. The controller analyzes the third signal to obtain flight status information relating to the effect of the physical parameters on the flight. U.S. Pat. No. 6,134,485 is incorporated herein by reference. Unfortunately, the pressure belt may not be suitable to be exposed directly to airflow. 
         [0007]    Accordingly, what is needed is a mechanism to protect the sensors, create a smooth aerodynamic surface over the pressure belt without changing sensor performance and maintain the integrity of the installation in flight. 
       SUMMARY 
       [0008]    The present embodiments provide a fairing system developed to reduce the flow disturbance around sensor elements allowing accurate measurement of the pressure distribution on an airplane exterior surface. The fairing also protects the sensors and electronics of the pressure belt from direct exposure to airflow. 
         [0009]    The fairing system includes a fairing assembly that can include shim stock and a thin rubber pad or substrate. The fairing assembly is configured to cover a sensor pressure belt, contour to the electronics on the belt and provide access at appropriate locations to allow for the measurement of pressure. 
         [0010]    The fairing assembly is shaped such that when installed on the airplane surface it minimizes the flow disturbance across the pressure sensing element allowing an accurate measurement of the local pressure. The fairing assembly is attached to the airplane surface using conventional methods, such as tape for ease of installation. 
         [0011]    In one aspect of the present embodiments, a fairing system is provided that includes a multisensor system for measuring physical parameters at a plurality of discrete locations about a surface of an object; and a fairing assembly including an aerodynamically configured surface having a central access portion in which the multisensor system is disposed. The fairing assembly provides environmental access to the multisensor system to measure local pressure on the surface. 
         [0012]    In yet another aspect of the present embodiments, a method is provided for assembling a fairing system. The method includes positioning a pressure sensing element at a measurement location on an object surface; positioning a substrate over the pressure sensing element; bonding a CRES sheet to the substrate; and forming a pressure port hole to provide environmental access to the pressure sensing element; and positioning a fairing body over the pressure sensing element, the substrate and the CRES sheet. 
         [0013]    In yet another aspect of the present embodiments a method is provided for assembling a fairing system. The method comprises positioning a plurality of pressure sensing elements on a belt segment, and securing the belt segment on an object surface to thereby position the pressure sensing elements at a plurality of discrete measurement locations on the object surface. The method further comprises positioning a substrate over the belt segment and the pressure sensing elements. The substrate includes a plurality of cavities, and at least some of the cavities contain the pressure sensing elements. The method further comprises positioning a cover sheet over the substrate, and forming a plurality of pressure port holes in the cover sheet. Each pressure port hole is located so as to provide environmental access to one of the pressure sensing elements. The method further comprises positioning a fairing body over the pressure sensing elements, the substrate and the cover sheet. The fairing body includes first and second aero wedges disposed to either side of a central access portion in which the pressure sensing elements are disposed. The fairing body provides environmental access to the pressure sensing elements. 
         [0014]    In yet another aspect of the present embodiments, a sensor package on an object surface is provided. The sensor package comprises a plurality of pressure sensing elements at a plurality of discrete locations on the object surface. A belt segment locates the pressure sensing elements at the discrete locations. A substrate overlies the belt segment. The substrate includes a plurality of cavities, and at least some of the cavities contain the pressure sensing elements. A cover sheet overlies the substrate. The cover sheet includes a plurality of port holes, and each port hole is located over one of pressure sensing elements. A fairing assembly including first and second aero wedges is disposed to either side of a central access portion in which the pressure sensing elements are disposed. The fairing assembly provides environmental access to the pressure sensing elements. 
         [0015]    The fairing system and installation method reduce installation flow time during an airplane test program. The fairing makes the airplane installation of the pressure belts efficient and thus reduces flight test costs. 
         [0016]    Additional advantages, objects, and features of the present embodiments will be set forth in part in the detailed description which follows. It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the present embodiments, and are intended to provide an overview or framework for understanding the nature and character of the present embodiments as they are claimed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The accompanying drawings are included to provide further understanding of the present embodiments, illustrate the various embodiments, and together with the description serve to explain the principles and operation of the present embodiments. In the drawings, the same components have the same reference numerals. The illustrated embodiments are intended to illustrate, but not to limit the present embodiments. The drawings include the following figures: 
           [0018]      FIG. 1  is a schematic block diagram of an aircraft: 
           [0019]      FIG. 2  is a simplified top view of a fairing system in accordance with the present embodiments; 
           [0020]      FIG. 3  is a simplified sectional view of the fairing system of  FIG. 2 ; 
           [0021]      FIG. 4  is a simplified sectional view of the fairing system of  FIG. 2 ; and 
           [0022]      FIG. 5  is a flowchart describing one embodiment of a method of assembling the present fairing system. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]      FIG. 1  schematically illustrates one embodiment of an aircraft. Embodiments of the present fairing and installation methodology for sensor pressure belts are adapted to be installed on an aircraft surface, such as on a wing, a fuselage, a tail or a door. The aircraft  20  includes an airframe  22  with a plurality of systems  24  and an interior  26 . Examples of high-level systems  24  include one or more of a propulsion system  28 , an electrical system  30 , a hydraulic system  32 , and an environmental system  34 . Any number of other systems may be included, as those of ordinary skill in the art will appreciate. Further, although an aerospace example is shown, the principles of the present embodiments may be applied to other industries, such as the automotive industry. 
         [0024]      FIG. 2  is a simplified view of one embodiment of the present fairing system  100 . Fairing system  100  includes a fairing assembly  102  having an outer fairing body  104  defined by aero wedges  106  and  108  formed about a central access portion  110 . Fairing assembly  102  also includes a substrate  206  and a cover sheet  208  shown in  FIG. 3 . The cover sheet  208  may comprise, for example and without limitation, a metal such as corrosion resistant steel (CRES), aluminum, titanium, etc., a plastic or a composite. Generally, disposed within central access portion  110  is at least one pressure sensing element  112  for analyzing physical parameters of flight data. In one embodiment, pressure sensing element  112  is coupled to belt segment  114 , which locates at least one pressure sensing element  112  at the required measurement location. 
         [0025]    Fairing assembly  102  is configured to cover pressure sensing element  112  and belt segment  114  by being made to contour to the electronics on belt segment  114 . Fairing assembly  102  provides access to ambient air at appropriate locations to allow for the measurement of pressure. 
         [0026]    Fairing body  104  is shaped such that, when installed on an airplane surface, it minimizes the flow disturbance across pressure sensing element  112  allowing an accurate measurement of the local pressure. Fairing body  104  can be made of any suitable material. For example and without limitation, the fairing body  104  may comprise a metal such as stainless steel shim stock, aluminum, titanium, etc., a plastic or a composite. 
         [0027]      FIG. 3  provides a sectional view of the fairing assembly  102  cut across belt segment  114 . As shown in  FIG. 3 , belt element  114  is coupled to airplane surface  200  using, for example, single or double sided tape and the like, such as without limitation 3M #92 tape. 
         [0028]    Fairing assembly  102  can be coupled to airplane surface  200  and made to surround belt segment  114  with aero wedges  106  and  108 . In this embodiment, belt segment  114  may be disposed within central portion  110  of fairing assembly  102  between aero wedges  106  and  108 . Fairing assembly may be mounted to airplane surface  200  using conventional methods, such as tape  204  and the like, for example and without limitation, 3M Y434 aluminum tape, for ease of installation. 
         [0029]    When properly positioned, a substrate  206  may be positioned over belt segment  114 . Substrate  206  can be made of any suitable thickness and material. In one embodiment, substrate  206  can be made of neoprene rubber to a thickness of about 3/32″ and the cover sheet  208  can be made of CRES having a thickness of about 0.005″. The cover sheet  208  may be bonded to substrate  206 . 
         [0030]      FIG. 4  provides a sectional view of fairing assembly  102  cut across belt segment  114  and pressure sensing element  112 . In contrast to  FIG. 3 ,  FIG. 4  shows a cavity  302  formed by removal of a portion of substrate  206  under the cover sheet  208 . Cavity  302  provides space for pressure sensing element  112  and other discrete components formed on belt segment  114  while covered by fairing assembly  102 . Sealant  304  is provided to seal cavity  302 . 
         [0031]    In one embodiment, at a prescribed location generally positioned above pressure sensing element  112  is formed a pressure port hole  306 . Pressure port hole  306  may allow for the measurement of local pressure by pressure sensing element  112  without the disturbance caused by turbulent airflow. Pressure port hole  306  can be of any suitable diameter, for example, 0.063″ diameter. 
         [0032]    It should be understood, as shown in  FIG. 2 , that belt element  114  can include a plurality of pressure sensing elements  112 . Accordingly, fairing assembly  102  includes a plurality of port holes  306  formed on the cover sheet  308  above each pressure sensing element  112 . 
         [0033]      FIG. 5  is a flowchart describing an assembly method  500  of forming fairing system  100  on the surface of an object. In step S 502 , a pressure sensing element is positioned at a measurement location on an object. In one embodiment, a plurality of pressure sensing elements  112  disposed on belt element  114  are secured by tape to the surface of an aircraft. The aircraft surface may be, for example, a wing a fuselage, a tail or a door. 
         [0034]    In step S 504 , substrate  206  is positioned over belt segment  114  and pressure sensing element  112 . Substrate  206  includes a hole which allows substrate  206  to be placed over belt element  114  and allow pressure sensing element  112  to emerge through substrate  206 . In step S 506 , the cover sheet  208  is bonded to substrate  206 . When bonded to substrate  206 , the area over the hole forms cavity  302  in which pressure sensing element  112  resides. In one embodiment, a sealant  304  can be used to seal cavity  302 . 
         [0035]    A pressure port hole  306  is formed in the cover sheet  208  to provide access to otherwise sealed cavity  302  to allow for the measurement of local pressure. In step S 508 , fairing body  104  including aero wedges  106  and  108  is positioned over belt element  114 , pressure sensing element  112 , and substrate  206 , such that belt element  114  resides in central portion  110  of fairing assembly  102 . Firing body  104  is secured to airplane surface  200  using tape  204  for ease of installation. 
         [0036]      FIG. 6  illustrates steps in one embodiment of the present methods for assembling a fairing system. In step S 600 , a plurality of pressure sensing elements are positioned on a belt segment. In step S 602 , the belt segment is secured on an object surface to thereby position the pressure sensing elements at a plurality of discrete measurement locations on the object surface. As described above, the object surface may be an aircraft surface, such as a wing, a fuselage, a tail or a door. In step S 604 , a substrate is positioned over the belt segment and the pressure sensing elements. The substrate includes a plurality of cavities, and at least some of the cavities contain the pressure sensing elements. In step S 606 , a cover sheet is positioned over the substrate. As described above, the cover sheet may comprise a metal, a plastic or a composite. 
         [0037]    In step S 608 , a plurality of pressure port holes are formed in the cover sheet. Each pressure port hole is located so as to provide environmental access to one of the pressure sensing elements. In step S 610 , a fairing body is positioned over the pressure sensing elements, the substrate and the cover sheet. The fairing body includes first and second aero wedges disposed to either side of a central access portion in which the pressure sensing elements are disposed. The fairing body provides environmental access to the pressure sensing elements. 
         [0038]    The above description presents the best mode contemplated for carrying out the present fairing and installation methodology for sensor pressure belts, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains to make and use this fairing and installation methodology for sensor pressure belts. This fairing and installation methodology for sensor pressure belts is, however, susceptible to modifications and alternate constructions from that discussed above that are fully equivalent. Consequently, this fairing and installation methodology for sensor pressure belts is not limited to the particular embodiments disclosed. On the contrary, this fairing and installation methodology for sensor pressure belts covers all modifications and alternate constructions coming within the spirit and scope of the fairing and installation methodology for sensor pressure belts as generally expressed by the following claims, which particularly point out and distinctly claim the subject matter of the fairing and installation methodology for sensor pressure belts.