Store separation methodology analysis

Abstract

Various computational methods and operational computer codes used to predict the aerodynamic coefficients and separation trajectories of aircraft stores are examined. The semi-empirical aeroprediction code Missile DATCOM is used to obtain the coefficients of a modeled store. These coefficients, together with the modeled ejection forces, are used in free-stream state-space equations of motion to predict the store trajectory. The results are compared with the Nielson Engineering and Research (NEAR) store separation code which provides accurate trajectory profiles, for speeds below the critical speed, by use of a vortex-lattice and panel method. Modification of the Missile DATCOM aerodynamic coefficients provides single-point state-space prediction of the store pitch trajectory within 30% of the NEAR code results. Store trajectories were restricted to the first 0.2 seconds of free flight.