Flow resistance of low-frequency pulsatile turbulent flow in mini-channels

The effect of channel size is inferred to associate with the fractions of turbulent Stokes layer thickness to half-height of channels. In mini-channels, the turbulence Stokes layer is almost filled the entire flow area. As channel height increasing, the turbulence, which generated in near wall layer, cannot timely propagates into pipe core region before decaying-which cause the impact of superimposed unsteadiness fades rapidly. The effect of dimensionless frequency is interpreted as the response time of fluid to the rapid changes of pulsatile pressure gradient.