“…The essence of local resistance loss is that due to the change in the flow direction and cross-section, fluid particles collide and friction in the local area, forming local eddy currents, resulting in local resistance loss. In hydraulics, the water flow has a large local head loss at the bend, reducer, and tee structures in pipelines, and many scholars have carried out significant amounts of research on local head loss [5,6]. In order to ensure the ventilation effect and reduce energy consumption, scholars have carried out a lot of research on the resistance characteristics of local components in urban traffic tunnels, mine laneways, utility tunnels, and other underground structures and air-conditioning ventilation systems.…”