Shielding weakening of high-velocity fluid against precipitation-static

Recent experiments have demonstrated that high-density space charge around a structure can shield precipitation-static on the structure’s surface, while high-velocity fluid can weaken this shielding effect. The physical mechanism behind this phenomenon remains unclear due to the limitations of experimental conditions and theoretical developments. To address this question, we propose a theoretical model to describe the process of precipitation-static, which captures multi-physics coupling effects including fluid field, particle motion and electric field. We also propose a method to describe the motion state of the charged particles in precipitation-static. We find that high-velocity fluid can weaken the shielding effect of space charge against precipitation-static by altering the forces exerted on charged particles, affecting their motion and spatial distribution as well as reducing the density of space charge around structure. Our findings emphasise the indispensability of considering fluid dynamics in understanding precipitation-static and offer valuable insights for future research.