Wind Tunnel Testing Validates Lockheed Martin JSF Aerodynamic Design
FORT WORTH, Texas---The Lockheed Martin Joint Strike Fighter (JSF) team validated its aerodynamic designs through successful testing in both low- and high-speed wind tunnels.
The testing validated the latest Preferred Weapon System Concept (PWSC) aerodynamic designs of all three variants -- the conventional takeoff and landing (CTOL) variant for the U.S. Air Force; the short takeoff and vertical landing (STOVL) variant for the U.S. Marine Corps, Royal Air Force and Royal Navy; and the carrier-suitable (CV) variant for the U.S. Navy. Due to the commonality in the design of the three variants, the same basic 1/15-scale model was used for all testing. Different wing and tail surfaces and appropriate fairings were attached to replicate the different variants.
"These wind tunnel tests give us a high degree of confidence in our aerodynamic models and in our aircraft designs,'' said Gerry Murff, director of the JSF PWSC design team. "Because of the high degree of aerodynamic similarity between our current PWSC design and the X-35 concept demonstrator aircraft that will fly next year, we are confident of the relevance of the data. We will have a low-risk entry into the Engineering and Manufacturing Development phase of the program that meets the customer's aerodynamic performance requirements.''
Approximately 200 hours of low-speed testing was conducted during August in the 16-by-23-foot Low-Speed Wind Tunnel at Lockheed Martin Aeronautical Systems, Marietta, Ga. Testing was performed in both takeoff/landing and "up- and-away'' configurations at speeds up to 200 knots.
"We were particularly pleased with the aerodynamic performance and the stability and control of the aircraft carrier variant,'' said Art Sheridan, leader of the JFS aerodynamic team. "Key performance features for the carrier suitability are landing approach speeds, munitions and fuel bring-back capability, and handling qualities in approach and landing aboard an aircraft carrier. These series of tests indicate we have a very solid design the Navy is really going to like.''
High-speed testing was conducted at the wind tunnel facilities of Veridian Engineering (formerly Calspan) in Buffalo, N.Y., and the Air Force's 16-foot Transonic Tunnel at Arnold Engineering Development Center in Tullahoma, Tenn. More than 200 test hours were completed in the high-speed series through early October. High-speed testing was conducted in the speed range of Mach 0.6 to 1.6.
The Lockheed Martin JSF's basic aerodynamic configuration resembles the F-22 Raptor, and as such, benefits from the thousands of hours of wind tunnel testing conducted previously in that program. The F-22's superb aerodynamic performance and handling qualities are now being verified in flight testing at Edwards Air Force Base, Calif. This similarity provides for a highly capable -- yet low-risk -- aerodynamic configuration for JSF.
Lockheed Martin received one of two JSF Concept Demonstration contracts awarded by the Department of Defense in November 1996. The Lockheed Martin JSF team includes Northrop Grumman and British Aerospace.
Flight evaluation of the demonstrator aircraft is scheduled to take place in 2000, with government selection of a single contractor for the Engineering and Manufacturing Development phase set for 2001.
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Wind Tunnel Testing Validates Lockheed Martin JSF Aerodynamic Design
