The physics and simulation of occupant traffic flow in the case of evacuating public building area

• Derive physics principles of occupant traffic based on fluid dynamics laws.
• Describe the process of occupant traffic in normal (i.e., non-panic) conditions.
• Examine the dynamic behavior of occupant traffic flows by means of simulation.
• Examine the occupant traffic flows phenomena related to the evacuation efficiency.
• Aim at optimization in building design and area deployment.

In cases where public building areas need to be evacuated, a large number of occupants are expected to be routed through exit(s) effectively. This paper combines two aspects of this problem. On the one hand, the traffic flows must be routed through the exit(s) according to some requirements, e.g., the time required to get everyone out is as short as possible. Hence, it is necessary to derive the embedded physics principles of occupant traffic, e.g., based on fluid dynamics laws, especially applicable to occupant traffic in normal (i.e., non-panic) conditions. The principles are helpful solving optimization problems such as finding out how many exits are needed, how wide the aisles should be set, or how to determine the area deployment according to the distribution of people in the building design. On the other hand, occupant traffic flows are dynamic in nature and phenomena related to the evacuation efficiency are examined by the simulation of System Dynamics, which is a way to illustrate and understand complex system behavior changing with time. In a simplified example, considering the typical occupants’ behavior modes, we simulate and compute the evacuation efficiency in terms of various building design strategies, to demonstrate the applicability and practical sense of the principles to real-world problems.