APS -70th Annual Meeting of the APS Division of Fluid Dynamics- Event - Miniaturized inertial impactor for personal airborne particulate monitoring: Numerical model

摘要

The rising level of fine particle matter's (PM$_{10}$, PM$_{2.5}$ and PM$_{1}$) pollution in the world has increased the interest in developing portable personal air-qualitity monitoring systems. To answer this need, we conceived a miniaturized inertial impactor.The development of such an impactor becomes more challenging as the diameter of the particles to be collected becomes smaller,since the velocities required to induce the impact of finer particulate matterbecome higher. To overcome these challenges, we modeled numericallythe fluid dynamics and particles transport within the impactor. Oursimulations show that the fluid flow within the impactor becomes unstable as the Reynolds number is increased to capture finer particles. Furthermore, the onset of these instabilities depends not only on theReynolds number but also on the geometry of the impactor. The unsteady flow within the impactor influences the trajectories of the particles to be collected, especially the smaller particles. The particles trajectories shows that the impaction location varies substantially as the Reynolds number increases and, consequently, the efficiency of the impactor deteriorates. Finally, we optimizethe design of our impactor to maximize itscollection efficiency.