Estimation of Free Floating Characteristics of a Close Coupled Canard Based on Computational Studies

The aim of this study is to bring out the usefulness of computational fluid dynamics (CFD) simulations in understanding the free floating characteristics of a close coupled canard of a generic fighter aircraft. In a typical canard design procedure, It is necessary to predict the canard behaviour when its actuation system fails and thereby its tendency to freely float subsequently. These free floating characteristics of a close coupled canard depend mainly on the canard hinge moment (moment about pivot axis) characteristics which are in turn based on the canard shape, location and hinge (or pivot) details. The understanding of hinge moment characteristics and thereby the free floating characteristics is essential for the accurate estimation of canard hinge loads, support structure loads, actuator size and canard operating schedule during flight. The paper compiles the CFD studies carried out in the transonic and supersonic regimes to estimate the canard hinge moments and comprehensive study of the flow features to understand the behaviour of the canard for its tendency to freely float.