  The application of local periodic heating for controlling a spatially
developing shear layer downstream of a finite-thickness splitter plate is
examined by numerically solving the two-dimensional Navier-Stokes equations. At
the trailing edge of the plate, oscillatory heat flux boundary condition is
prescribed as the thermal forcing input to the shear layer. The thermal forcing
introduces low level of oscillatory surface vorticity flux and baroclinic
vorticity at the actuation frequency in the vicinity of the trailing edge. The
produced vortical perturbations can independently excite the fundamental
instability that accounts for shear layer roll-up as well as the subharmonic
instability that encourages the vortex pairing process farther downstream. We
demonstrate that the nonlinear dynamics of a spatially developing shear layer
can be modified by local oscillatory heat flux as a control input. We believe
that this study provides a basic foundation for flow control using
thermal-energy-deposition-based actuators such as thermophones and plasma
actuators.
