New Blockage-Correction Method for Separated Flows in a Subsonic Wind Tunnel

Introduction W ALL-INTERFERENCE-CORRECTION methods can be categorized into the classical method, the computationalfluid-dynamics method, the measured-boundary-condition method, and the adaptive wall method. Currently, the classical method and the measured-boundary-condition method are most widely used because of the superior productivity of data and the operational simplicity. The classical method is easy and efficient to use because additional measurements are not required for the correction and works well for conventional simple aircraft models of a small size up to moderate angles of attack. However, at high angles of attack, the classical method is known to have a tendency of overcorrection and thus can be used only as a qualitative guidance.1−4 The measured-boundary-condition method can be applied to any model configurations, including internal devices such as the model support and the sting. It is generally accepted that the correction made by the measured-boundary-condition method is more reliable than the classical method at high angles of attack. However, this method requires expensive instrumentations, large computer time, and pretests for database construction.1,3,4 Although the flight envelope of conventional aircrafts is mostly restricted to moderate angles of attack below stall, modern fighters are designed to perform high angle-of-attack maneuver at poststall regions. To reduce the time and the cost involved in the design cycle of a new aircraft, the test data from wind-tunnel testing must be provided to the designer as quickly and accurately as possible.5 Thus, a fast, efficient, and reliable wind-tunnel wall correction method that