Flow Regimes in Protective Masks

摘要

The appearance of a transition from laminar flow to turbulent flow has been discovered in respiratory protective masks when donned by some, but not all, human subjects. The cause of the turbulence in the M17 protective mask has been found to be flow constriction in the nosecup region. It has been mathematically shown that this turbulence reduces the time available for expiration which subsequently causes reduced tolerance time of men working while wearing the mask. (Author)