A Numerical Demonstration of the Establishment of Unconfined-Flow Conditions in a Self-Correcting Wind Tunnel.

Abstract : Sears' self-correcting wind tunnel concept for achieving unconfined, interference-free flow conditions about a model by controlling the flow at the test section walls is simulated. A numerical model for the flow within the test section is used in conjunction with the functional relationships which must be satisfied to insure that the flow is unconfined. The basic iterative nature of the concept is examined, and it is demonstrated that the iteration converges readily to unconfined-flow conditions. The effects on the flow about the model of truncating the controllable portion of the test section walls at 4.5 chord lengths up- and downstream of the model quarter chord is shown to be negligible. (Author)