Flow field structures and mode decomposition analysis of dual synthetic jets impinging plate

To reveal the flow field characteristics of dual synthetic jets impinging plate, the large eddy simulation method was used to numerically study the flow of dual synthetic jets impinging plate. The Lagrangian coherent structure of the flow field was identified on the basis of the finite-time Lyapunov exponents, and the results were compared with the vorticity results in the Euler frame. It is found that the vortex structure of the jet core area of dual synthetic jets is exceeding complex and rich under the alternating action of periodical jets, and there is a pair of stable vortex structure far away from the core. Lagrangian coherent structures are well corresponding to the vorticity, provided guidance for the layout design of dual synthetic jets impingement cooling. Proper orthogonal decomposition analysis is performed on the flow field of dual synthetic jets. The results show that the first-order mode is approximately symmetrical about the central axis of the exit of the actuator, and its energy accounts for 35% of the total energy, and the first 6 modes account for 80%. According to the characteristics of the flow field reflected by the first 6 modes, the flow field of dual synthetic jets impinging plate has a high degree of symmetry.