Calculation of Flexible Wall Shapes and Preparation of Control Tapes for the Bedford 8-ft x 8-ft Wind Tunnel

This report describes an application of a digital computer to the aerodynamic design and automatic control of a large wind tunnel with flexible walls. The computational problem was threefold : first, calculation of the wall shapes for a set of 'pivotal' operating speeds between M = 1 and 2"8; second, computation of the necessary movements of the set of screw jacks which flex the walls ; and finally, preparation of the set of digitally punched control tapes. A new mathematical approach was used for the first part in order to avoid singularities in the partial differential equations governing the flow in the convergent-divergent nozzle of the tunnel. The work was started in 1953 on the ACE Pilot Model at the National Physical Laboratory and completed on one of the Royal Aircraft Establishment DEUCE computers.