Design Research On Optimization Of Dust Pollution Under Engine Compartment Of Heavy Commercial Vehicles Based On Critical Threshold

While people more and more aware the impotence of enviromental protection,so people pay more attention to environmental project as they pursue happy lives.As far as vehicles are used as means of transportation,in addition to performance requirements,people also put forward more environmental protection requirements.Among them,automobile dust is an inevitable issue.Studies have shown that dust pollution caused by motor vehicles can account for more than 30% of the total urban particulate pollution.As a heavy-duty commercial vehicle that carries the main transportation work,the road conditions on which it travels are more complicated,and the dust particles pollution caused by its operation area or active area is more serious.In this paper,a numerical calculation method(CFD)is used to carry out research,establish a three-dimensional numerical simulation model,use a standard k-ε turbulence model to simulate the flow field changes in the calculation domain,and predict the trajectory of solid particles in the flow field based on the gas-solid two-phase flow theory.In this paper,through a large number of heavy commercial vehicle road test tests on unpaved roads and stationary tests on putty powder grounds,the degree of dust pollution is analyzed,and the critical threshold value of the dust-generating wind speed on the ground under the engine room is 6m/s,and taking this as an important reference to evaluate the effect of dust reduction,we began to explore feasible dust reduction schemes and measures.By monitoring the temperature of the temperature-sensitive parts in the engine compartment of the actual vehicle test and the distribution of the cooling fan’s landing speed,the simulation model is compared and verified,and the calculation result of the simulation model is determined to be basically reliable.Then the model flow field is analyzed and discussed,and specific schemes for reducing dust particles are studied.In the calculation domain of the vehicle model,the instantaneous particle quantity in the detection space of the cross-section volume is established on the left,right and rear areas of the vehicle body respectively.After processing the obtained data,draw a graph curve,analyze the difference of the dust in different directions of the car body,and compare the front and back effects in different directions after the dust reduction measures are taken to obtain the optimal dust reduction measures plan.Studies have shown that optimizing the internal layout of the engine room,guiding the airflow of the cooling fan,and suppressing the secondary acceleration of solid particles by the airflow in the middle of the vehicle can effectively reduce the transportation of dust particles into the space.Among them,adding a wind collecting plate behind the fan to guide the airflow to reduce particle dust has the best effect.Finally,the three solutions were integrated and discussed,so that the maximum wind speed of the engine bilge was lower than the critical threshold,and a significant effect of reducing the dust particles by 34.7% was achieved.Finally,consider the impact of the dust reduction measures taken on the thermal environment of the engine compartment,and take specific measures to optimize the performance of the cooling system.