The Internal Flow Field Simulation Of Grain Heap By CFD Method

Grain is an important strategic material, and its storage security is related topeople’s basic subsistence, the country’s security and stability. The grain temperatureand its relative humidity are the key factors which are related to the security of grainheap, and the mechanical ventilation is an important guarantee for the storage.Computational Fluid Dynamics (CFD) method is selected and used to simulatethe temperature field under quasi-steady state storage and the pressure field undermechanical ventilation state, Two CFD mathematical models are established by thefluid theory and principles of mass, momentum and energy conservation. One is underquasi-steady state, and the other is under mechanical ventilation state.the mathematicalsimulations are finished by determination of simulation area and boundary conditions,grid division, models selection and calculation. Based on the research of grain storageunder quasi-steady state and mechanical ventilation state, we simulated thetemperature field under quasi-steady state storage and the pressure field undermechanical ventilation state respectively, the following conclusions can be drawn fromthe analysis of simulation results and experimental results.1.Firstly, simulation of small granary and warehouse test under quasi-steady statewere studied, and then we simulated the temperature field under quasi-steady state ofsquat silo and large horizontal bin, the simulation results are almost coincident to theexperimental data, the temperature fields and its changes of different positions indicatethat the initial boundary conditions lead to the differences between simulations andexperiments. It’s proved that the CFD method used to simulate the temperature fieldunder quasi-steady state storage is feasible.2.For the pressure field simulation under mechanical ventilation state, it agreeswith reality, and the result of simulation agrees well with that of experimental. For theerror between simulation results and experimental data, it is related to the simplifiedmodel, experimental error of physical parameters, poor gas tightness of granary and so on.3.The research of internal flow field simulation by using CFD method, which canbe used to optimize the ventilation systems and further simulation.