New Method of Estimating Wind Tunnel Wall Interference in the Unsteady Two-Dimensional Flow (Nouvelle Methode D'Estimation de la Perturbation des Ecoulements Instationnaires par les Parois d'une Soufflerie).

摘要

A new method of estimating wall interference in unsteady flow is presented. This method is valid for subcritical flow within the accuracy of the linearized small disturbance theory. The main feature of the method is the use of measured pressure along lines in the flow direction near the tunnel walls. This method is particularly effective in a tunnel with ventilated walls because it does not require the representation of wall characteristics with unreliable mathematical expressions. Results of some numerical examples indicate that the new method produces satisfactory results except for cases when the reduced frequencies are close to the tunnel resonance frequencies. For the case of an airfoil in pitching motion, the method has been used to correct the amplitude of the angle attack and the time lag in the motion. (Author)