A Study on Urban Traffic Congestion Pressure Based on CFD

With the rapid advancement of urbanization, the problem of traffic congestion in cities has become increasingly severe. Effectively managing traffic congestion is crucial for sustainable urban development. Previous studies have indicated that fluid dynamics theory can be applied to address flow problems in transportation, and this article aims to utilize CFD to solve congestion issues in urban road traffic. Firstly, a similarity analysis is conducted between fluids and traffic flow at the theoretical level. By converting parameters, the formula of fluid is derived into the formula of traffic flow, thus demonstrating the feasibility of using CFD in traffic flow research. On this basis, targeting recurrent congestion and non-recurrent congestion scenarios, 2D road fluid domains and constraints are constructed based on the common characteristics of each congestion type area. By using Fluent (2018) software to analyze the flow conditions under different congestion characteristics, the smoothness of fluid motion can be used to find out the problems causing traffic congestion and conduct an analysis to reveal the microscopic mechanism behind congestion formation. For different types of congestion, in order to clarify the effectiveness of congestion mitigation measures, the geometric design of road intersections and diversion measures are discussed in depth. The traffic pressure is analyzed by adjusting the vehicle inlet angle at intersections or controlling the vehicle flow speed. Finally, the optimal design scheme is obtained by comparative analysis. It is concluded that for the roundabout, it is optimal to change the entrance angle to 20°. For the on-ramp merging area, it is optimal to set the ramp entrance as a parallel ramp. For recurrent congestion, it is required to pass at an optimal speed of 30 km/h. Based on the theory of previous studies, this paper further proves that the congestion degree of traffic flow under specific assumptions can be expressed by the pressure of the fluid. It also provides new ideas for optimizing urban road design and solving vehicle traffic congestion problems.