Fluids analysis of the thermal micropump for a fuel atomizer

摘要

This article applies the thermal micropump to the injector of the fuel atomizer of a motorbike and makes a fluid behavior analysis by means of computational fluid dynamics, with water and Stoddard solvent as working liquids. The purpose is to discuss the speed, shape, and path of the droplets, the internal flow field, and work liquid replenishment after the injection of the micropump under two different situations: when the external air is at the condition of rest, and when it flows at a speed of 15.0m/s. This micropump for a fuel atomizer consists of 50 independent micropumps, with orifices of 50mum diameter and a working frequency of 5kHz. The results of the study indicate that Stoddard solvent, with its lower density, is subject to the influence of external flowing air, which will result in the breaking of the droplets and the offset of the flying path. The flow of external air not only changes the shape of the liquid droplets and the flying path, but also delays the starting time of working liquid replenishment. The time gap between the initiations of replenishment in different working liquids is decreased and the remaining air pores in the cavity of the micropump become fewer under the effect of air cross-flow.