Surrogate Modelling of Active Flow Control

Abstract

The development of a surrogate model for predicting aerodynamic force and moment increments due to three active flow control technologies for aircraft conceptual design is discussed in this paper. The active flow control technologies are: supercritical circulation control for roll, pitch and yaw control; forebody blowing for yaw control; and high-lift boundary layer control for augmentation of conventional control surfaces. These models were developed because existing empirical methods for predicting conceptual design aerodynamics are unable to estimate the aircraft response due to these active flow control technologies. The geometric parameterisation of the flow control technologies and the approach to incorporate aircraft planform influences on active flow control is presented. Data for the surrogate model consisted of a combination of existing data from literature, experiments, and a large database of computational fluid dynamics results generated specifically for the model. An overview of the data processing is given, and finally comparisons between the surrogate model and full three-dimensional computational fluid dynamics simulations of an aircraft are presented. The surrogate model is shown to predict the aerodynamic response of active flow control to levels of accuracy sufficient for conceptual design, and make predictions in timescales suitable for real-time flight simulation software.