1. (h) Solution Procedure To understand the necessity of the procedure given by Figure 3(b), f i r s t expand Equation (10) giving
2. This section presents r e s u l t s from unsteady calculations on blocked grids. A NACA0012 airfoil i s o s c i l l a t e d i n pitch about i t s quarter chord point a t a Mach number of 0.755 and a reduced frequency of 0.1628. The mean angle of attack,^^, of the airfoil was 0.016 degrees and the unsteady angle of attack amplitude, was 2.51 degrees. The angle of attack history of the a i r f o i l i s given by