Download or read book Calculations of Some Unsteady Transonic Flows About the NACA 64A006 and 64A010 Airfoils written by R. J. Magnus and published by . This book was released on 1977 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unsteady transonic flows over airfoils were calculated using a program based on the unsteady Euler equations. The approximate numerical solutions were obtained using an explicit (Lax-Wendroff) difference scheme. Calculations were made for the 64A006 airfoil at zero angle-of-attack in flows with Mach number 0.822, 0.854 and 0.875. Three unsteady flows caused by a quarter-chord flap oscillating with an amplitude on the order of one degree at specific reduced frequencies (k = omega C/U sub infinity) near 0.4 were analyzed. The results were compared with other available calculations and the experimental data of Tijdeman. Responses for an airfoil in a ventilated-wall wind tunnel rather than in a free-stream were also calculated. Exploratory study of the changes to be expected with a weakened shock (an attempt to simulate a main effect of the interaction of the shock with airfoil boundary layer) was done for one case at Mach number 0.875. Oscillatory flows over the 64A010 airfoil at zero angle-of-attack in a Mach 0.80 stream were also calculated. Plunging motion at reduced frequency 0.4 and pitching motions at reduced frequencies 0.4 and 0.5 were calculated. (Author).