NACA-TN-2495

Abstract

INTRODUCTION <br>The data presented herein are the results of two wind-tunnel investigations in the Georgia Institute of Technology 9-foot wind tunnel. These tests were conducted under the sponsorship and with the financial assistance of the National Advisory Committee for Aeronautics as part of an extensive wind-tunnel investigation to determine the aerodynamic characteristics of balanced control surfaces in order to supply data for design purposes. <br>Force-test measurements were made in three-dimensional flow to determine the aerodynamic characteristics of the following control-surface arrangements: <br>(1) A series of tail models having NACA 0009, 66-009, 0015, and 66(215)-014 profiles, a sweep angle of 13.50 at the 25-percent-chort line, a tail aspect ratio of 3.36, and taper ratio of 0.4 with various unswept trailing-edge flap configurations. The flap configurations tested included 30-percent-chort elliptic and sharp-nosed aero-dynamically balanced flaps and internal-balance flaps, as well as some 30-percent-chort plain (radius-nose) flaps. The balanced flaps had a nose balance overhang of 35 percent of the local flap chord and a constant flap nose gap. Plain tabs and two sized of unshielded horn balances were tested with some of the models. <br>The NACA 66-009 and 66(215)-014 airfoil models were also constructed without the cusp to give straight-contour flaps. <br>(2) A series of tail models having NACA 0009 or 9-percent-thick circular-arc profiles, a sweep angle of 400 at the 25-percent-chord line, a tail aspect ratio of 3.30, and a taper ratio of 0.4 with balanced and plain flaps which were swept back 30.70 at the hinge line. The model flaps were 30 percent of the tail chord measured parallel to the air stream and had a 35-percent-flap-chord overhang. The flap nose gap was held constant for the various overhangs tested. Only one size of shielded horn was tested in conjunction with the plain flap. <br>A More complete description of the models is given in the section entitled "Apparatus, Models, and Tests."