Towards the design of synthetic-jet actuators for full-scale flight conditions : Part 2: Low-dimensional performance prediction models and actuator design method

Due to the large parameter space that is involved in the design of synthetic-jet actuators used for flow separation control, it is essential to develop low-dimensional models for actuator-performance prediction and establish the conditions for design optimisation so that candidate actuators can be identified at the initial design stage. In Part 2 of this paper, three low-dimensional models that are capable of predicting actuator performance for synthetic jet actuators of different scales are described. Using these models the parametric relationships required for optimising the actuator performance are established. Finally, based on a better understanding of the fluid mechanics of synthetic jets (described in Part 1) and the improved modelling capacity, a methodology for designing synthetic-jet actuators used for flow separation control at full-scale flight conditions is developed. This methodology is illustrated in the design of actuators for delaying flow separation on the leading and trailing edge devices of a multi-element high-lift system of a typical commercial-aircraft wing at take-off conditions. 2007.