Preliminary Method for Estimating Hinge Moments of All-Movable Controls

摘要

The objective of the first phase of this 2-phase study is to develop a hinge-moment prediction method for all-movable controls for angles of attack up to 20 deg, control deflections to 15 deg, the complete range of roll angles, and Mach numbers from subsonic to hypersonic if possible. Based on a review of the literature, it was decided to modify on existing computer program, MISSILE 2, to improve its accuracy of hinge-moment prediction. A method based on strip theory and shock-expansion theory is used to improve the prediction of fin axial center-of-pressure position. A special method is included to account for canard and body vortices on fin axial center-of-pressure location. Special extrapolation procedures for the underlying data base were added. Comparison between hinge-moment data and prediction show good agreement at zero roll between Mach numbers of 1.3 and 3.7, but not at transonic speeds. When body or canard vortices are close to tail fins on the leeward side of the body, the predictions were usually not good. Canard fin hinge moments were generally well predicted.