Dynamic Modeling of a Thermally-Driven Micro Diffuser Pump

In this study, we present the dynamic modeling of a micro diffuser pump by employing the commercial software package CFDRC. Two types of time-dependent pressure boundary conditions are applied to the inlet. Sinusoidal and square wave functions with various amplitudes and frequencies are used. The results indicate a rectification effect such that a net flow in the divergent direction of the diffuser is gained over the time. In addition, the model is able to show the correlation of flow rate with frequency by flow circulation effects. This impact of the transient flow on the pumping performance is discussed. The modeling results are also compared to experimental data found in the literature. The net flow rates predicted by the 3D modeling are found to have good agreement at low excitation frequencies. To evaluate the validity of the imposed pressure boundary condition, the heat transfer model of the evaporation process is used.