Simulation and Test of Nozzle Optimization of Residual Film Barrier Device based on Fluent

Abstract

The residual film barrier device is installed at the bottom of the picking head of the cotton picker to block the negative pressure at the hole of removing impurities to suck the residual film, and the nozzle is one of its important working parts. The jet air curtain generated by the nozzle can effectively block the residual film on the surface from being sucked into the picking head through the hole of removing impurities due to negative pressure. The structure of the nozzle is optimized to improve the performance of the air curtain, which in turn improves the residual film blocking effect, reduces the residual film content in cotton and improves the quality of cotton. The optimized nozzle is trapezoidal structure, the upper bottom edge D is 25mm, the velocity inhomogeneity coefficient of opening 1 and opening 2 are 4.82% and 5.25% respectively, the velocity deviation is 0.19, the nozzle flow field characteristics are good. It was found that the average relative errors between the simulated and measured values of velocity on both sides of the nozzle were 1.54% and 2.32%, and the correlation coefficients were 96.0% and 95.4%, respectively, with good correlation and reasonable nozzle optimization results.