Forced pulsatile flow to provoke chaotic advection in wavy walled microchannel heat sinks

Through a series of numerical simulations, thermo fluid performance of wavy walled microchannels under steady and pulsatile flow regimes are examined and the phenomenon observed was explained by looking into the advection problem from dynamical systems point of view. It is observed that for steady regime, chaotic advection may happen for highly modulated channels and with a significant pressure drop penalty. However, in the second part of the paper, it is shown that for slightly modulated channels under pulsatile flow regime, significant increments in heat transfer may be observed while pressure drop is kept reasonable. The study on steady regime examines the effect of geometrical parameters like channel expansion factor, wall waviness and channel aspect ratio, keeping Re constant. On the other hand, for the pulsating regime, geometry is kept constant while the effects of pulsation frequency and pulsation amplitude are examined. For both regimes, significant enhancement in heat transfer is observed when chaotic advection is present while this comes with large pressure drop penalties for the steady regime and acceptable pressure loss for pulsatile flow regime.