Numerical Study of the Flow Condition of the Hydrodynamic Levitated Mechanical Micropump

Active liquid cooling is one of the most efficient and promising strategy for extreme thermal issues. As is the power source of the active liquid cooling system, a reliable and powerful micropump is urgently needed. In this study, we numerically studied the fluid flow of a hydrodynamic levitated micropump, considering the fluid flow in the motor. We found that the load capacity of the journal bearing is not influenced by the pump fluid flow. However, the pressure distribution of the journal bearing results in the dissymmetric pressure distribution in the spiral groove bearing, leading to worse stability of the axial levitation performance. The axial suspension force is at least 1.0N with the liquid film thickness of 15μm and is sufficient for the rotor with weight of 30g to be stably levitated in the fluid. Owing to the pressure difference inside the pump, the balance point of the rotor should be lower than the theoretical design when the micropump is operating.