Numerical investigation of micron particle inhalation by standing thermal manikins in horizontal airflows

Computational fluid dynamics computations were conducted to investigate the particle inhalation characteristics of a thermal manikin standing in a horizontal airflow with different orientations, leg postures, wind speeds and particle sizes. The computations revealed that only when the manikin's thermal plume moves into the breathing zone (namely, the manikin is facing the lee side) could the body heat affect the characteristics of particle inhalation. Further computations demonstrated that, when facing the lee side, the manikin's particle inhalation is highly sensitive to its leg posture. When the legs are separated, air can flow through the gap, causing more particle entrainment into the breathing zone from the lower level. Although the thermal effect of body heat is gradually suppressed with increasing wind speed or particle size, different leg postures have different environmental sensitivities.