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Stealth - Additional Note Lockheed Martin F-117A / Faceting A paper published [1] in Moscow at the theoretical physical institute spurred the Lockheed Skunk Works team to develop a computer program that could calculate radar reflectivity, using the faceted [2] design approach for the F-117A Stealth Fighter (1977). At first the stealthiness, achieved by faceting the aircraft surface, played havoc with the aerodynamics and the response to pilot input. Coming as a result of the aerodynamically troublesome design, a fly-by-wire flight computer control system was developed. Reduced control surface sizing through stability augmentation systems was one of many issues implemented to reach stealthiness integrity, coupled with actuation efficiency to suit various mission operational needs.
Northrop Grumman B-2 / Continuous Curvature [3] A smooth shape is generally selected for an airfoil to operate in subsonic flow. For supersonic airflow, with the existence of shock waves, a diamond-shaped airfoil is usually the chosen design. Modifying the gravitational field with electrogravitics a continuous streamline pattern (buffer zone) is obtained at supersonic speeds, even with the B-2's smooth airfoil design. This compares favourably to flying disks. That is, the approach flow is able to sense the presence of the B-2. In terms of 100% antigravity (e.g. ET-crafts), the approach flow is seemingly able to sense instantaneously the oncoming craft. For a given engineering problem, attempting to solve noninertial fluid flow, or dealing with incompressible fluid and infinite velocity of sound, the mathematical complexities often mask the physical circumstances. For its new stealth bomber (1980), Northrop embarked upon a systematic development of various families of airfoil. Numerous experimental investigations of the flow around the chosen airfoil, and initial aircraft trials indicated a high lift to drag ratio. Thus, the results obtained clearly demonstrated the B-2's superiority to maintain steady level flight for a relatively low thrust requirement. A requisite for flying long distances efficiently with 40,000 lbs of payload. The interaction between generated engine thrust and aerodynamic drag makes up the available performance of an aircraft. The Continuous Curvature concept added to the beauty of the airfoil design. Visualize smooth transitions in curvature, exact in measurement and detail, everywhere on the aircraft surface, aimed at minimizing radar reflectivity. Massive computational and simulation capabilities made, in part, the innovative B-2 possible. Such as, the developments in computer chip memory/processing speed, and the steadily progressing software packages (FEM, CAD, CAM, etc). An electronic warfare (EW) jamming system generating signals to cancel those sent by the enemy was originally intended for the B-2. Now the program has made great strides with a new generation EW package in research and development. [1] "Method of the edge waves in the physical theory of diffraction", P.Ya. Ufimtsev. Air Force Systems Command - Foreign Technology Division. [2] External shaping of the aircraft with the arrangement of many flat triangles, small pyramids or sloping sides to deflect the high frequency electromagnetic waves away from its source - the radar (RAdio Detection And Ranging). 3] In addition to electrogravitics. Read: Jan Riis-Christensen published: 29.07.04. ___________________________________________________ Searching for previous articles by Jan Riis-Christensen? Read more
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