The Research Of The Coupling FLUENT Software With IDEM Software And Its Application

China is a developing agricultural country with a large population. It has vast landresources but only a small proportion of land is arable. Modernization of agriculture hasbecome an inevitable trend to the development of China’s agriculture. The coverage ofagricultural modernization is wide. Precision seeding is a very important part and the onlyway to achieve the modernization of agriculture. Precision planting can sow the seedsquickly, effectively and accurately in the field in accordance of the requirements of aperson by the modern agricultural machinery. It can create the best conditions for the growthand development of the seed, avoid unnecessary waste of a large number of seeds, reduce theplanting labor, guarantee a steady growth of the crop and increase the yield.The requirements of precision sowing machinery to the precision planting operations areurgent. As the core component of precision sowing machinery, the structure of precisionmetering device directly affects the accuracy, speed and cost of sowing as well as theadaptability of seed etc. So the research of precision metering device will further improvethe precision sowing quality and accelerate the pace of development of precision sowing.Currently, most of the researchers are still using the traditional method on the study of themetering device. That is for designing, producing, prototype testing, statistical analysis,re-designing, re-producing and re-testing. It is repeatedly done until it meets therequirements. Many structural parameters of seed metering device rely on the experience ofthe designers on the study. The agricultural experiment is seasonal so at the meantime it is awaste of human and financial resources. It may also not get the best optimization results soobviously, it does not meet the requirements of modern precision sowing.Through the development of science and technology, a new research method was born andthat is the use of the coupling of discrete element with computational fluid dynamics methodto research the pneumatic metering device.Discrete element method (Discrete Element Method, DEM) were proposed by Cundalland others. It uses numerical methods to deal with the mechanical behavior of granularmedia system. The basic idea is to simplify granular group into the collection of particleswith a certain shape and mass. It gives the contact some kind of contact mechanics model,the model parameters between the particles, the particles with contact boundary, considersthe different mechanical physical properties of the contact action between the granular andthe granular with contact boundary.Computational Fluid Dynamics (Computational Fluid Dynamics, CFD) is rapidlydeveloping with the development of technology of computer hardware and software from1960s. It is an emerging branch of fluid mechanics. It uses numerical methods to solve partial differential equations of fluid flow control. It can get the distribution of the flowparameters in the flow field and as the time change by solving these flow control equation.The discrete element software developed by our group can do a good analysis of contactaction between particles and particles with mechanical components and the movement ofparticles. The computing function is gradually mature. It can do the dynamic simulation ofits working process and performance by modifying the CAD model of the mechanicalcomponents, and can analyze the movement of particles in the mechanical components bychanging particles and mechanical models.The software FLUENT is the most popular CFD software in the market. It has a verypowerful fluid calculation, and it takes60%of shares at market in US. It is also the mostwidely used in China based on the online survey. Moreover, it can couple the discreteelement calculation of software IDEM with the fluid calculation of software FLUENT. Thismethod is being used for the simulation analysis of the gas blowing metering device.Obviously, fluid-solid coupling interaction calculation based on the discrete element methodcan be applied in many fields. It provides convenience for the development and optimizationof the mechanical components about particles and fluid.Firstly, this paper studied the operation method of the FLUENT software. On this basis, ittransmitted commands via text document to establish contact IDEM software with theFLUENT software. It can fulfill external operation on FLUENT software from IDEMsoftware. It can set the fluid calculations parameters and choose solver settings. Thus, it canuse the fluid calculation based on FLUENT software.Secondly, this paper studied the secondary development of FLUENT software. It usesself-defined function UDF to output the flow field message which is calculated by FLUENTsoftware to a text document. It controls the calculation of each time step and data transfer inFLUENT software through the figures that change from another text document.This paper researched the method of Coupling CFD with DEM. It tells about a IDEMsoftware interface coupled with FLUENT software. It is used to receive flow fieldinformation which output to a text document by FLUENT software and it can be used fordiscrete element method calculations. It can also control the receiving and the calculationprocess by the change data from the other text document digital change. Furthermore, itachieved the coupling of the FLUENT software with IDEM software.Finally, this coupling program was tested in the case of the flow field and the particlesadded in the flow field. The classic pipeline flow model and the lid-driven model are usedfor testing the situation which is only in the flow field. It compared the results of flow fielddisplay from FLUENT software. The comparison shows that the flow field messageextracted by IDEM software from FLUENT software is correct. Pipeline flow model andelbow model are used for testing the situation which is by adding particles to the flow field.It compares the simulation results from EDEM software coupled with FLUENT softwareand the results display identical. It shows that the coupling calculation from the FLUENTsoftware with IDEM software is feasible and effective. On the basis of the above work, the coupling program is used for the analysis of theprocedure and the performance of the work of a blowing-metering device. It was comparedwith experimental results. We can see that the coupling procedure being used for the researchof blowing metering device is effective and feasible. It establishes a new method for theresearch and design of blowing metering device.