Impedance Matching of Synthetic Jet Actuators to Flow Fields
Executive Summary
The goal of the proposed investigation is to advance the understanding of the dynamic coupling between “zero-net mass” or “synthetic jet” actuators and the flow fields they are used to influence. Our industrial partners, from the Phantom Works Division of the Boeing Company, are working with us on this project because they want to implement synthetic jet actuator technology for use in active flow control strategies on next generation aircraft. Our research program will lead to a fundamental understanding of synthetic jet actuator-flow field-lifting surface relationships and of actuators driven by both low and high mechanical impedance synthetic jet driver mechanisms. The program will study innovative zero-net-mass actuator concepts for cost-effective active flow control to help enable design strategies for actuator placement and operation of a new generation of rotary wing aircraft and proof-of-concept devices that demonstrate the unique potential of these actuators. Our goal of realizing here-to-fore unachievable flow control performance will be achieved through fundamental science and engineering studies that focus on the key research areas summarized below.
Primary Objectives
- Advancing understanding of synthetic jet actuator designs for maximizing their influence on flow fields in stationary and rotating frames of reference
- Developing and validating a modeling tool for predicting the influence of actuators on boundary layers and cross flow
- Integrating the validated model with lifting surface models to provide a tool for optimizing placement of an appropriate combination of these actuators to achieve desired performance objectives
Research Description
The first 18 months of efforts will focus on modeling and experimental validation in flat plates and cylinders with both low and higher impedance actuators, after which the appropriate combination of devices will be embedded in scaled wing and fuselage models for validation of performance models that incorporate 3-dimensional interaction effects.
The research will involve model development, analytical and numerical simulations and a significant experimental effort. We will design, build and test two classes of synthetic jet actuators: i) high displacement, low blocked force synthetic jet actuators driven by electroactive polymers and ii) lower displacement, higher blocked force synthetic jet actuators driven by piezo bimorphs. Simultaneous and cooperative research on these actuator concepts will facilitate comparison of these technologies in cross flows and over a range of speeds. One grad student thesis will study each actuation concept, and they will both be used for undergraduate honor thesis research projects. Actuator characterization will take place under the same flow field conditions and on the same structures. A reduced order analytical model for prediction of actuator influence on flow fields will be developed that captures the bi-directional effects of a single jet on blocking cross flow and of the cross flow entrainment in the jet. Models will be validated against wind tunnel measurements and will culminate in prediction of flows controlled by actuators embedded in lifting surfaces.
