Research On Airflow Cleaning Device Used On Plot Wheat Combine Harvester

Cleaning system play an important role in the harvester, especially for plot combine harvesterwhich strict in technology. The primary mission of design is to improve cleaning rate, de-crease the damage of grain and guarantee the grain don’t mixed with others. In this paper, onthe basis of the exiting researches about the cleaning system of harvester and according to therequirement for agriculture technology of plot harvester, the major work is to design and re-search cyclone separator cylinder of airflow cleaning for cleaning system of plot combineharvester, then computational fluid dynamics (CFD) is presented to analyze and simulate.Due to difference of physical properties between different materials, the force situation andtrajectory of motion are also different. Therefore, it is necessary to analyze the force and ki-nematic of the threshed materials (i.e. grain husks, short stalks and dust) in wheat combineharvester. Then the dimension and structure of cyclone separator cylinder is given combinethe analysis result of force and kinematic and empirical design method.Then three-dimensional solid model of cyclone separator cylinder aforementioned has builtand FLUENT is proposed to analyze and simulate. Turbulence model, pressure-velocitycoupling, discretization schemes and pressure gradient of Gaseous phase is RNG k-, SIMP-LEC, QUICK and PRESTO, respectively. And model of kinematic trajectory for kernel andimpurities is dispersed phase model (DPM). Through the numerical simulation, distribution ofvelocity, pressure and trajectory of kernel and impurities are obtained. As the simulation re-sult shows, firstly, there is two obviously zones, i.e. high speed and low speed, velocity ofthem are about7.9~20.4m/s and1.13~4m/s, respectively. Secondly, trajectory of kernel andimpurities is stochastic and complex under the effect of drag from airflow, collision amongkernels, impurities and wall of cyclone separator cylinder. Based on the simulation analysis,the effects of dimension parameter for different structures, such as, length of cylinder, lengthof cone and diameter of cylinder, are taking into consideration. And the separation efficiencyof the structure aforementioned is given. According to the effects a improved cyclone separa-tor cylinder is presented at the end.