Micromachined actuators have been used successfully to control leading-edge vortices of a delta wing by manipulating the thin boundary layer before flow separation. In an earlier work (Lee, G.B., Ho, C.M., Jiang, F., Liu, C., Tsao, T., and Tai, Y.C., 'Distributed Flow Control by MEMS,' American Society of Mechanical Engineers; International Mechanical Engineering and Exposition Nov. 1996), we demonstrated that small disturbances generated by these microactuators could alter large-scale vortex structures and consequently generate appreciable aerodynamic moments along all three axes for flight control. In the current study, we explored the possibility of independently controlling these moments. Instead of using a linearly distributed array of microactuators covering the entire leading edge as done in the previous study, we applied a shorter array of actuators located on either the forward or the rear half-section of the leading edge. Both one- and two-sided control configurations have also been investigated. Data showed that the pitching moment could be generated independently by appropriate actuation of the microactuators. To understand the interaction between the microactuators and leading-edge vortices, we conducted surface pressure distribution, direct force measurements, and flow visualization experiments. We investigated the effects of microactuators on the vortex structure, especially vortex core location. Experimental results showed that asymmetric vortex pairs were formed, which leads to the generation of significant torques in all three axes.
ASJC Scopus subject areas
- Aerospace Engineering