Visualization of Flow Induced by Human Sneeze

Abstract

Human sneeze has been analyzed by flow visualizations, a particle image velocimetry (PIV), a phase Doppler anemometer (PDA) and a numerical calculation. For the visualization, a home video camera and a high-speed video camera are applied. The visualization indicates the temporal and spatial developments of human sneeze. The shape of it is almost the same as the plume. From the visualization, the penetration length and velocities in both directions are obtained. The ratio of the development in stream-wise and the lateral directions is nearly equal at the initial stage. After, the sneeze develops in stream-wise direction, and it loses its velocity rapidly. The PIV results show that the tip of the sneeze had large velocity and the tail has small velocity. The PDA results show that a lot of droplets have less than 3 μm in diameter and about 2m/s in mean velocity. Results of numerical simulation is also compared with that of experiment.