Numerical Simulation Of Particle Deposition On Case Board

The application of case in the fields of engineering and peoples livelihood are becoming more and more popular,and its operating efficiency and life span are related to industrial production and peoples lives.At present,dust-proof measures for the case mainly include reducing the ingress of external dust and secondary dust removal.Due to the limitation of experimental conditions and cost,the current academic research on the particle deposition in the case board is still relatively vague.Therefore,there is an increasing demand for predicting particle deposition with the numerical simulation methods,but few scholars have carried out relevant numerical simulation studies on case board.Based on a certain type of case and the ANSYS FLUENT platform,this paper develops and couples a particle deposition model through a user defined function(UDF),and carries out the following three numerical simulation studies on the particle deposition of case board:In the first part,a numerical simulation study on particle deposition in the semicircular rough elements wall with different roughness environments.By constructing a semicircular rough element two-dimensional ventilation duct with different parameters,and based on the Reynolds stress model and the discrete phase model,the flow field and particles are solved respectively.At the same time,combined with the particle deposition model,the deposition characteristics of particles on the wall of the rough element were analyzed,and the deposition characteristics of the square rough element were compared.The results show that the particle deposition rate on the semicircular wall is lower than the particle deposition rate on the square wall.Furthermore,when the rough element is at e/D= 0.02 and p/e = 3,the particle deposition rate changes greatly,but it does not change much under other parameters.In addition,the windward side of the semicircular rough wall is the main area of particle deposition.The second part explores the factors affecting the particle deposition characteristics of the board in the simplified case.A simplified three-dimensional geometric model was constructed based on a certain type of case,and k-ω and DPM were used to solve the flow field and particle motion respectively,and the UDF model was combined to determine the particle deposition characteristics.On the one hand,the theoretical analysis of the particle force characteristics is carried out,on the other hand,the numerical simulation of the particle deposition characteristics in different areas of the case board under different particle diameter and different inlet velocity is carried out.The results show that the main forces on particles are drag force and gravity,while electric force and thermophoretic force have little effect on particle motion.Compared with the upper board,the lower has stronger particle deposition characteristics.At the same time,the particle deposition traces of the upper and lower board are similar,and the windward surface of the device is the main area of deposition in the case.The larger the particle size has the stronger the deposition characteristics,but the deposition of small particles is more obviously affected by turbulence,and they are mainly deposited on the leeward area of the device and the surface of the board.In addition,inlet velocity has a greater impact on the deposition characteristics for large particles on the windward side,but has little effect on the deposition of small particles in other areas.In the third part,the numerical simulation of the particle deposition of the real case board is carried out,and the accuracy of the existing model is compared with the 6-day experimental data.Based on the flow field and particle solution methods above,the existing model can effectively predict the particle deposition trend of the board and the total mass of deposition on the windward surface of the upper board device.At the same time,the existing models still have deficiencies such as improper processing of particle tracking numbers and normal particles removal mechanism.This research provides scientific guidance for the subsequent research on the particle deposition phenomenon of the case.