Numerical Simulation of the Effects of Design Parameters on the Performance of Tractor Powered Flail Choppers

Abstract

Several design parameters of flail chopper were studied under a wide range of field and crop conditions to improve chopper performance. However, the effects of parameters on the internal straw flow characteristics that influence straw chopping and spreading performance are still unknown. In this paper, Computational Fluid Dynamics (CFD) were used to analyze the influence of three operating parameters (rotor speed, forward speed and hood clearance) and two structural parameters (fan blade number and flail tip clearance) on the flow characteristic in the tractor powered flail chopper. The pressure contours, maximum negative pressure and flow rate at the machine inlet were considered in the analysis of feeding performance. Velocity at 21 sampling points, area weighted and maximum velocities at the outlet were also considered for straw spreading performance. Streamlines from three sampling sections were analyzed for straw flow-ability.