NACA-ACR-4C11

Abstract

<u>INTODUCTION</u> <br>Tests were made in the LMAL 7- by 10-foot tunnel of a 0.7-scale model of the XF6F vertical tail surface. These tests were undertaken to obtain data for use in data useful for the XF6F vertical tail in particular. Additional tests were made to determine tab characteristics for two different tabs and flow characteristics over several of the shielded horns. <br>The various shielded horn balances tested included models of the original horn on the XF6F airplane and of shielded horns of four chords, each of which was tested with two different spans and nose shapes. The variation in horn size covers the range from no balance to over &#8211; balance. Flow characteristics were determined by tuft tests of two of the smaller horns and pressure-distribution tests of two of the larger horns. The pressure distribution data show the local velocity distribution of "shielded horn" will generally be referred to as "horn" followed by a designation to indicate the horn size and nose shape. <br>Tests were made of an unshielded horn balance to determine whether any correlation between shielded and unshielded horns was possible. These tests were also the logical extension of those of the short-span shielded horns. <br>Characteristics of the tab were determined in order to have information useful in the design of any balancing or unbalancing device that uses tabs, as well as to have the characteristics of the particular trimming tabs tested. A round-nose tab of the same plan from and size as the original tab was tested to determine the variations in characteristics, if any, from the original tab. The round-nose tab represented the type of tab usually used on wind-tunnel models, Both tabs were tested sealed and unsealed.