Fractal Diffusion And Aggregation Control Of Soot Particles Of Diesel Tail Gas Based On Complex Network

As the main component of diesel exhaust emissions,soot mainly consists of polycyclic aromatic hydrocarbons.The air quality is seriously affected by the mixture of soot particles and dust.When the concentration of particles in the air is too high,it will significantly reduce the visibility,affect the visual range,cause traffic obstruction;it will also reduce sunlight,change the temperature and precipitation and other environmental climate.In addition,a large number of medical studies have shown that the increase of mortality caused by respiratory diseases or cardiovascular and cerebrovascular diseases is closely related to the concentration and size of particles in the air,which has seriously harmed human health.Therefore,it is very important to analyze and control the movement process of soot particles and the morphology of aggregates.Fractal theory is a non-linear subject that describes the characteristics of things and explores the essence of things.Fractal theory lays a theoretical foundation for uncovering the nature of seemingly complex and irregular objects in nature.In recent years,fractal theory is widely used in mathematics,biology,physics and geology.In the electron micrograph of diesel engine exhaust particles,it can be clearly seen that soot particles naturally diffuse and aggregate in the atmosphere,and the final condensate shows a typical fractal structure.In order to study the fractal diffusion control of soot particles,this paper introduces the Diffusion Limited Aggregation model and Diffusion Limited Cluster Aggregation model in fractal theory,and uses complex network simulation to study the fractal diffusion dynamics of soot particles in two-dimensional space.Based on the fractal diffusion process of soot particles,this paper simulates the long-range jump of soot particles in the diffusion process,and controls the fractal diffusion of soot particles by changing the network parameters.The main contents are as follows:(1)Establishment of control model of fractal diffusion and aggregation of soot particles(2)Control of fractal diffusion and aggregation of soot particles based on scale-free networkIn this paper,the scale-free network is introduced into the fractal diffusion and aggregation model of soot particles.The diffusion and aggregation of soot particles can be realized by using the scale-free network.By changing the structural parameters of the scale-free network,the control of the fractal diffusion and aggregation of soot particles is studied.The functional relationship between the structural parameters of the scale-free network and the fractal dimension of soot aggregation is creatively established and quantitatively analyzed The influence of different network parameters on the fractal dimension of soot aggregates can control the morphology of soot aggregates from loose to tight.In addition,the potential function model of uniformity measurement is used to quantitatively analyze the homogeneity of soot aggregates.The experimental data show that the aggregates based on scale-free network have better uniformity than those based on small world network and classic DLA model.The conclusions can be used for reference in diesel exhaust treatment and air pollution control.(3)Control of the aggregation of the fractal diffusion group of soot particles based on the small world networkIn order to better fit the actual aggregation process of soot particles,this paper proposes a fractal diffusion cluster aggregation model based on small world network,which uses the small world network connection as the long-range jump channel of soot particles.By changing the structural parameters of small world network,the prediction and control of soot particle fractal diffusion cluster aggregation with long-range jump phenomenon are studied.In view of two typical parameters of small world network,the control variable method is used to simulate the control of soot particle fractal diffusion cluster aggregation under different control parameters.By calculating the fractal dimension and multifractal spectrum of soot aggregates,the control effect of the aggregates under different control parameters is analyzed.The simulation results verify the effectiveness of the control.In addition,this paper innovatively introduces Deng entropy to quantitatively analyze the stability of soot aggregates.The experimental results show that with the increase of small world network parameters and threshold parameters,the entropy of soot particle aggregates gradually decreases and the aggregates tend to be more stable.The relevant conclusions have important theoretical and practical significance for the study of the condensation process and movement mechanism of soot particles with long-range jump phenomenon in practice,and for the study of the purification technology of diesel engine exhaust.