The ability to enhance heat-transfer processes with a minimal amount of added energy expenditure has application in many industrial sectors. One avenue to pursue this is in the use of passive controls to trigger the promotion of secondary topological structures in a flow. These structures can be beneficial to the mixing and the transfer of heat into and out of the working fluid. In this instance, the influence of period heating and cooling patterns in the direction of the flow is considered with regard to the linear- stability of longitudinal vortices in a Poiseuille flow. The growth or suppression of these particular structures is investigated over an applicable range of flow parameters. Two physical arrangements are considered, the first case is that of only periodic wall heating being applied to the channel, while the second investigates the periodic heating’s impact on the stability of the flow in the instance of a heated lower wall
