The flow characteristics in the triangular grooved channel by pulsating flow at low Reynolds number has been investigated. The influence of several main parameters on flow resistance is analyzed. The parameters are Reynolds number

Womersley number and pulsating amplitude. The results show that

flow resistance in the triangular grooved channel by pulsating flow is higher than that in steady state. Flow resistance in pulsating state increases with the pulsating amplitude

and there is a Womersley number for the highest flow resistance. It also measures that the imposed pulsating flow causes phase difference between the curve of velocity and the curve of pressure drop. In addition

the phase difference is determined by Womersley number

but irrelevant to the pulsating amplitude. To explore the cause from what has been discussed above

the mathematical model of pressure drop is established. The reason why flow resistance in pulsating state is higher than that in steady state is that

compared with steady state

there is a Δpr in the mathematical formulas of pressure drop in pulsating state

and the average value of the Δpr in a cycle is more than 0. The pressure drop of form drag is mainly affected by Womersley number

and the total pressure drop increases with the pulsating amplitude. The results from theoretical analysis also indicate that

the accelerating pressure drop induces the phase difference

and the value of phase difference is affected by frictional resistance

form drag and accelerating pressure drop.