The observed output z(x) of a physical apparatus is assumed to be a weighted integral of the input f(x), the weighting function g(x) of the apparatus being known. This paper describes a convenient numerical method of determining f(x), based on expanding z(x) and g(x) in Fourier series, having regard to the noisy nature of actual observations.
5.Dv,cpwo A%, -syAPI-08/03 ABSTRACT The AP05 code was evaluated when applied to configurations with boattails. Results of the evaluation indicated the AP05 predictions for normal force, center of pressure, pitch and roll damping moments needed improvement. As a result new and improved methods were developed and incorporated into the AP05 to be released as the AP09. Improvements include body alone lift characteristics for Mach numbers less than 2, low angle of attack improvements for roll and pitch damping for configurations with long boattails, incorporation of an improved boundary layer displacement model and refinement of several other existing methods. In addition, new methods were developed to predict nonlinear roll and pitch damping. Comparing the new and improved methods to existing experimental data indicated significant improvements in roll and pitch damping, normal force and center of pressure predictions compared to the AP05. However, validation of the AP09 code was not as complete as desired due to limited generic nonlinear roll and pitch damping data. Also, most of the available nonlinear dynamic derivative data has larger than desired accuracy boundaries due to model sting and wind tunnel wall interference issues. Weapons affected most by the new AP09 methodology are mortars, low drag bombs and projectiles in that order. However, the nonlinear dynamic derivative predictions affect all weapons. The AP09 is thus the most accurate and robust of the Aeroprediction Codes to date.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.