Numerical Investigation of the Tesla-Type Valve Performance in a Valveless Micropump in the Range of Low Frequencies

The performance of Tesla-type valves, used in micropumps for low frequency driving force, is examined. A three-dimensional (۳-D) and unsteady numerical analysis of fluid flow inside a valveless reciprocating micropump is carried out. Ferrofluidic valveless micropump is one practical sample of this kind of micropumps that operate in the range of low working frequencies. To model the reciprocating movement of flow actuator, two time varying functions that includes sinusoidal and step excitation are employed. Also, the performance of nozzle-diffuser valve for the same range of frequencies is examined, and its performance is compared with the Tesla valve. The simulation results of the ferrofluidic valveless micropump with the nozzle-diffuser valve show good agreement with the experimental data and linear relation between head and flow rate in micropump is confirmed. Performance curve, flow rate versus head curve, is obtained for different working frequencies. Based on results, micropump with Tesla type valve in comparison to micropump with nozzle–diffuser type valve has lower maximum flow rate in the all range of operating frequencies. However, it has higher maxumum head inhigh operating frequencies. These results show the weakness of the Tesla type valve in low working frequencies and Reynolds numbers.

کلیدواژه ها:

Valveless Micropump ، Tesla Valve ، Threedimensional Simulation ، Low Frequencies