Simulating the Motion of High-Density Human Crowds as a Low Reynolds Number Newtonian Fluid

The synchronized movement of large crowds of people are common at both sporting events and in response to traumatic events (such as active shooters) in crowded venues. Proper understanding of high-density crowd movement and behavior can be used to design safer building layouts to reduce the risks of suffocation and trampling in crowds. Due to the independent thinking of individuals, it is typically difficult to model crowd motion due to the inability to accurately predict what individuals may do within the crowd. However, if the density of the crowd is very high and the goal of the majority of the crowd members is similar, then it is feasible to treat a high-density crowd as a low Reynolds number Newtonian fluid. In this work, a bifurcating hallway was simulated at several crowd velocities and densities. In all cases, the Reynolds number based on hallway width was between 45 and 77. High-pressure regions in the hallway were identified, and the layout of obstructions and diversions in the path were adjusted to reduce the pressure difference, resulting in a reduced risk of death by suffocation.