Pivotable Strakes for High Angle of Attack Control

A series of pivotable strakes have been tested in combination with a 44 degree swept wing to determine their ability to provide pitch control at high angles of attack. The tests were carried out in the Langley 7- by 10-Foot High-Speed tunnel at nominal Mach numbers of 0.3 to 0.4. A total of five strakes with various aspect ratios and shapes were tested at negative deflection angles of 5°, 10°, 15°, and 20° through an angle of attack range up to approximately 50°. In addition, a cranked delta wing with 70 degree sweep was tested with two different pivotable apex flaps. This paper will shows lift, drag and moment data for the complete configurations as well as for the separate contributions of the strakes and fuselage nose which are mounted on a second balance. Generally strake deflection was found to have a significant effect on moment while lift over drag changed very little.