Simultaneous control of friction drag reduction and heat transfer augmentation by travelingwave-like blowing/suction

The possibility of simultaneous control of skin-friction drag reduction and heat transfer augmentation by traveling wave-like blowing/suction is explored for laminar channel flow. In addition to the constant temperature difference condition, uniform heat generation is considered for the temperature field so that the boundary condition similar to that in a velocity field holds. Friction drag reduction and heat transfer augmentation are simultaneously achieved when the wave travels in the upstream direction. The global phases of streamwise velocity and temperature fluctuations are found to oppose each other, which eventually leads to dissimilarity between the friction drag and heat transfer. Direct numerical simulation confirms that this dissimilar control effect also can be obtained in a turbulent channel flow.