Download or read book Effect of Compressibility on the Pressures and Forces Acting on a Modified NACA 65,3-019 Airfoil Having a 0.20-chord Flap written by W. F. Lindsey and published by . This book was released on 1946 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation has been conducted in the Langley rectangular high-speed tunnel to determine the effect of compressibility on the pressure distribution for a modified NACA 65,3-019 airfoil having a 0.20-chord flap. The investigation was made for an angle-of-attack range extending from -2 to 12 deg at 0.20 flap deflections from 0 to -12 degree. Test data were obtained for Mach numbers from 0.28 to approximately 0.74. The results show that the effectiveness of the trailing-edge-type control surface rapidly decreased and approached zero as the Mach number increased above the critical value.