Optimization Design Of Cyclone Separator Of Air Filter Intake System For Heavy Truck

Cyclone separator is an important part of the air cleaner forward air intake system and it is used to separate the large particles of dust in the air under the action of centrifugal force when the air flow through the swirl impeller.But as the part of the air filter intake system for heavy truck,there are large flow resistance,dust deposition and low filtration efficiency problems with cyclone separator need to be solved.Considering the complexity of the internal flow field in the cyclone separator and the time consuming of the experimental method,the computational fluid dynamics has been used in this thesis,the flow velocity pressure distribution pressure loss and separation efficiency under several circumstances have been simulated.For the gas field in the cyclone separator-RSM model for turbulent flow,QUICK format foe difference scheme,PRESTO format for pressure discretization and SIMPLEC algorithm based on FVM method is used for calculation the flow field.And the gas solid two phase field is calculated by using the Euler-Lagrange method.The results show that the tangential velocity in the separator plays a leading role.In the cyclone separator,axial velocity below the swirl impeller is a negative value,and this illustrate that there is reflux around the central axis,which will increase the flow resistance and the pressure loss.Static pressure around the central axial is a negative value,and it extends to the exhaust port,which will affect the separation effect.Due to the existence of dirt mouth,the velocity and pressure change significantly at the close of the dirt mouth.The classification efficiency of particles increase as the particle diameter increase,but too small or too large particle filtration efficiency of particles is not very good,and part of the captured particles accumulate in the bottom of dust collection chamber,is easy to cause secondary pollution,and affects the filtration efficiency.According to the analysis results,the structure optimization design of the cyclone separator is carried out.The influence of parameters such as the variation of the exhaust port radius,the length of the inner wall of the exhaust port,the inclination of the exhaust port and the inclination of the collector cavity on the velocity,pressure distribution,resistance and filtration efficiency of the flow field are analyzed.The results show when the radius of the exhaust port is 54mm,inner wall of the exhaust port height is 147mm,dirt mouth angle is 24 degrees,and dust collection chamber bottom angle is 6°,the axial velocity beneath the impeller distribution is more uniform,and the absolute value of the velocity decreases,which illustrate the backflow is improved,the pressure drop is obvious reduced,the fluid flow resistance in the separator is decreased,and the filtration efficiency is improved.