ANTENNA FAIRING AND METHOD
First Claim
1. An aerodynamic fairing secured to an exterior surface of an airborne mobile platform for enclosing an electronic device supported on said mobile platform, the fairing being positioned on said exterior surface downstream from a nose of the mobile platform, so as to be in a boundary layer when said mobile platform is in flight, the fairing comprising:
- a top portion;
a pair of side portions extending from said top portion to define a volume, said side portions extending substantially perpendicular to said top portion;
a chord length designated by X;
a chord thickness at a local center line representing a thickness designated by Z;
wherein a ratio of Z/X lies within a range of about 11-13%;
said fairing further having a drag coefficient that is relatively constant and less than a value of about 0.10 below an airspeed of about Mach 0.9;
said fairing further having a peak Mach number for airflow over a longitudinal centerline of said fairing that is no greater than about 1.2 at an airspeed of said mobile platform of about Mach 0.85;
said fairing further having a frontal portion, said frontal portion forming an angle at a half height point thereof of between about 20 degrees to about 32 degrees, and having a pressure distribution (Cp) that is positive at a trailing edge of the fairing; and
said volume of said fairing being sufficient to fully enclose said electronic device underneath said fairing when said fairing is positioned over said electronic device and secured to said exterior surface of said mobile platform.
1 Assignment
0 Petitions
Accused Products
Abstract
A fairing suitable for enclosing a component mounted on an exterior surface of a mobile platform, and more particularly on an outer surface of a high speed mobile platform such as a jet aircraft or an aerospace vehicle. The fairing provides aggressive closure angles for optimum RF performance when used to house an antenna that is scanned to varying azimuth and elevation angles. The fairing further provides low aerodynamic drag, is scalable to enclose components having wide ranging dimensions, and provides attached flow with minimum separation of airflow thereover for airflows experienced by high speed jet aircraft, and reduces or eliminates RF reflections within the fairing from the RF beam of the antenna.
41 Citations
20 Claims
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1. An aerodynamic fairing secured to an exterior surface of an airborne mobile platform for enclosing an electronic device supported on said mobile platform, the fairing being positioned on said exterior surface downstream from a nose of the mobile platform, so as to be in a boundary layer when said mobile platform is in flight, the fairing comprising:
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a top portion; a pair of side portions extending from said top portion to define a volume, said side portions extending substantially perpendicular to said top portion; a chord length designated by X; a chord thickness at a local center line representing a thickness designated by Z; wherein a ratio of Z/X lies within a range of about 11-13%; said fairing further having a drag coefficient that is relatively constant and less than a value of about 0.10 below an airspeed of about Mach 0.9; said fairing further having a peak Mach number for airflow over a longitudinal centerline of said fairing that is no greater than about 1.2 at an airspeed of said mobile platform of about Mach 0.85; said fairing further having a frontal portion, said frontal portion forming an angle at a half height point thereof of between about 20 degrees to about 32 degrees, and having a pressure distribution (Cp) that is positive at a trailing edge of the fairing; and said volume of said fairing being sufficient to fully enclose said electronic device underneath said fairing when said fairing is positioned over said electronic device and secured to said exterior surface of said mobile platform. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An aerodynamic fairing secured to an exterior surface of an airborne mobile platform to completely cover and enclose an antenna mounted on said exterior surface, the fairing further being positioned on said exterior surface so as to be behind a nose of the airborne mobile platform and thus within a boundary layer when said airborne mobile platform is in flight, the fairing comprising:
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a top portion; a pair of side portions extending from said top portion to define a volume for said fairing, said volume being sufficient to enclose said antenna therein; a chord length designated by X; a chord thickness at a local center line representing a thickness designated by Z; wherein a ratio of Z/X lies within a range of about 11-13%; said fairing further having a drag coefficient that is relatively constant and less than a value of about 0.10 below an airspeed of about Mach 0.9; said fairing further having a peak Mach number for airflow over a longitudinal centerline of said fairing that is no greater than about 1.2 at an airspeed of said mobile platform of about Mach 0.85; said fairing further having a frontal portion forming a leading edge surface for the fairing, and a tapering rear portion, said frontal portion forming an angle at a half height point thereof of between about 30 degrees to about 31 degrees, and said fairing further having pressure distribution (Cp) that is positive at said trailing edge portion; said top portion and said tapering rear portion forming a radius of curvature that is about 125 inches-135 inches; and the fairing further including at least one vent formed on one of a port side and a starboard side for equalizing pressure on inner and outer surfaces of the fairing. - View Dependent Claims (14, 15, 16, 17)
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18. A method for aerodynamically enclosing an antenna able to be aimed at varying azimuth and elevation angles, and being mounted on an exterior surface of an airborne mobile platform at a point on said airborne mobile platform so as to be within a boundary layer while said airborne mobile platform is in flight, the method comprising:
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forming a fairing including a frontal portion, a top portion, a pair of side portions on opposite sides of the top portion, and a trailing edge portion, said frontal portion, said side portions, said top portion and said trailing edge portion defining a volume sufficient to enclose said antenna with said side portions extending substantially perpendicularly from said top portion; forming the fairing such that; a chord thickness (Z) along a local centerline of the fairing, in relation to a chord length (X) of the fairing, defines a ratio of about 12%; a drag coefficient thereof is relatively constant and less than a value of about 0.10 below an airspeed of about Mach 0.9; a peak Mach number for airflow over a longitudinal centerline of said fairing that is no greater than about 1.2 at an airspeed of said mobile platform of about Mach 0.85; said frontal portion forms an angle such that a tangent line at a half height point thereof forms an angle of between about 30 degrees to about 31 degrees, relative to the a surface that the fairing is mounted on; and said top portion and said tapering rear portion form a radius of curvature of about 130 inches, such that said angle and said radius of curvature enable minimum angle with the RF scan line of about 20 degrees to be provided relative to said frontal portion and said tapering rear portion; and a pressure distribution (Cp) is positive at a trailing edge of the fairing. - View Dependent Claims (19, 20)
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Specification