Flow Field Analysis And Structure Optimization Of The Airstream System For Road Sweeper Based On FLUENT

Environmental protection has been a real problem in the modern urban construction and the development of social economy.With the improvement of people's living standard, neat appearance of the city and clean living environment has become the common aspirations of the whole society. To accelerate the development of product and technology of city environmental sanitation machinery is an urgent matter to promote the construction of environmental protection facilities of the city. As the main tool of cleaning and maintenance of the road surface, the road sweeper has been widely used on the streets of the city. But the current road sweeper has widespread problems with low efficiency and high energy loss, which is caused by the unreasonable distribution of flow field in the airstream system. This paper relied on a road sweeper R & D project, carried out a series of flow field simulation and structure optimization work on airstream system.This article started from the suction nozzle, which was the entryway of dust particles. The structure of the suction nozzle determined the distribution of the internal flow field, which also affected the work efficiency. On the basis of studying the air and dust particles, the internal flow field of the suction nozzle model was simulated by using parametric modeling and computational fluid dynamics method. Through the analysis of various parameters on the feature point based on the results of simulation, the evaluation to the original structure was made. Based on the parametric model, CFD technology was used to further explore the influence of structure parameters on its flow field distribution, and thus put forward the improvement project of the original structure. After simulating and analyzing the optimization model, the results showed that the optimization effect was significant. Based on the DPM model, the simulation of two-phase flow in the suction nozzle was completed, the particle trajectory was tracked and the results showed a good dust-suction effect. In addition, considering the actual working condition of the sweeper, the effect of the driving speed and ground clearance on the performance of the suction nozzle was analyzed.The dust-collection system at the end of the airstream system can realize the separation and collection of dust from airflow. Dust removal was the main function of the dust-collection system and gravity sedimentation was the primary dust removal method widely used on sweepers. After studying the characteristics of air flow and the motion law of dust particles, the gravity sedimentation mechanism of dust collection box was analyzed. Based on the CATIA platform, the simplified calculation model of the dust collection box was established and the internal flow field was simulated by using the FLUENT solver. By analyzing the simulation results, the unreasonable part of the flow field distribution was proposed. In order to achieve the optimization of internal structure of dust collection box, the paper tried to design a new kind of dust removal cover with the guide direction both vertical and horizontal. The simulation results of the optimization model showed that the new dust removal cover had a significant role to improve the flow field distribution. Finally using the prototype vehicle for simple road test, the results showed that the sweeper performance had reached up to the standard.Research work in this paper introduced a new way of product design and development to the airstream system by using CFD technology, which can provide some theoretical guidance and reference for the design of new and efficient sweeper.