Experiments for the Reduction of Wind Tunnel Wall Interference by Adaptive-Wall Technology
Final rept. Oct 1977-Sep 1978
ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFB TN
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Experiments were conducted in the AEDC Aerodynamic Wind Tunnel 1T to evaluate the applicability of adaptive-wall technology to reduce wall interference in a transonic wind tunnel. Data were obtained on a six-percent- blockage, two-dimensional, NACA 0012 airfoil section with two different, adaptable porous wall configurations. One configuration featured variable longitudinal control of the local hole angle and the other featured global porosity control. The experiments demonstrated that adaptive-wall techniques could be used to significantly reduce wall interference effects. Although neither wall configuration could be adjusted to duplicate the pressure distributions calculated at the tunnel boundary control surface with adaptive- wall technology to produce interference-free conditions, matching the pressure level upstream of the model and minimum pressure in the vicinity of the model adequately reduced the wall interference. One of the most effective means for matching these global parameters was plenum pressure adjustment thus, some refinement may be obtained through segmented plena control.
- Fluid Mechanics