A COMPARATIVE STUDY OF TWO UCAV TYPE WING PLANFORMS - AERO PERFORMANCE STABILITY CONSIDERATIONS

摘要

Currently there is a revival of interest in flying wings for military (and civil) use. The military context has arisen from the future "stealthy" HALE and UCAV aircraft. Questions on aerodynamics, control and structural efficiency arise. Compared with conventional wing/tail arrangements, flying wings have a special set of very different constraints. These are mentioned. Without a trim surface, the constraints on the wing pitching moment dictate the design camber and twist Control power requirements can be high because of effectively short moment arms. The camber and twist are strongly dependent on trim stability margins. This aspect needs to be understood in detail when comparing different types of planforms. This paper is concerned with the study of two wing planforms for UCAV applications. It is inspired by the need to understand a variety of wings (in public domain) that are, at first sight, aimed at similar missions. The main emphasis has been on developing and understanding cruise design camber and twist with Cm constraints of stable, neutral and unstable static" margins. Spanwise lift and drag loadings have also been presented. Camber design has been via attained thrust methods and a modal approach. It is shown that starting from basic information such as the planform, we are able to predict the anticipated performance with sufficient confidence for comparative assessments. Further work is proposed in several areas.