Numerical Simulation And The Experimental Study Of Air Flow Field Of Air-and-screen Cleaning

This paper introduced the researching overview about the combine harvester both at home and abroad, and the development of cleaning device, and analyzed the problem of cleaning system of the current domestic Combine. The air speeds of seventy-five fixed positions were measured, which got the general distribution of airflow field. The cleanness and loss rate of cleaning test with supply were determined, which can offer basis on looking for a suitable distribution of the air flow field for rice's cleaning. Quadratic Response Surface Model between airflow speed of sieve surface and its speed and the angle of Centrifugal fan were set up, which forecast airflow distribution. The model was tested. Quadratic Response Surface Model is effective. Using neural network tools offered by MATLAB, three BP neural network models were set up, one for wind-force factors and the air speeds of seventy-five fixed positions, and the other, for the air speeds of seventy-five fixed positions and the cleaning results, include clean rate and losing rate, the another for wind-force factors and the cleaning results. The prediction results of three models indicated that they are effectual, therefore can be used for predicting or controlling. Using FLUENT, a large-scale fluid project emulation software, a numerical simulation for cleaning air flow field were made, the intact equivalence line chart and vector graph of the air flow speed distribution were obtained, which provide more overall understanding to the cleaning air flow field speed distribution.Through of the trial , researched the relations of wind-force factors and the air speeds of seventy-five, the air speeds of seventy-five fixed positions and the cleaning results, and wind-force factors and the cleaning results. This subject set up quadratic response surface model and BP neural network models of air flow field, which can be used in air flow field prediction and controlling of rice's cleaning and the cleaning results effectively. They may be of certain directive significance to the cleaning device development and the research of rice's combine harvester. Based on the current rice and wheat's Combine, a numerical simulation for cleaning air flow field were made, which offer theoretical guidance for improving the design of Combine cleaning system. Through analyzed speed and the angle of Centrifugal fan, which Impact Combine sieve surface airflow distribution.