Lumped parameter model and numerical model of vapor bubble-driven valve-less micro-pump

Abstract

A lumped parameter model for a vapor bubble-driven valve-less micro-pump is established, in which the mass transition process is considered, and a numerical model is built to validate it. The lumped parameter model consists of a bubble dynamic model based on Rayleigh-Plesset equation, a phase-change model based on thermodynamics, and a pump chamber pressure model derived from the mass conservation law accounting for the resistance of the nozzle and diffuser. The numerical model is established in ANSYS Fluent. Source terms of mass and energy transfers caused by phase change are taken into the control equation using user-defined function. The result shows that these two models have a good agreement with each other, in terms of bubble dynamics and flow performance. The proposed analytical model allows a convenient tool to study the vapor bubble-driven valve-less micro-pump and has a potential to guide the design of the micro-pumps.