Predicting header wheat loss in a combine harvester, a new approach

Abstract

Header loss of wheat in a combine harvester was modelled and evaluated at Badjgah Research Station, Shiraz University, Shiraz, Iran. The main objective was to develop a characteristics dimensionless model to predict the header loss based on Buckingham pi theorem. A conventional New Holland TC5070 combine harvester was monitored in field studies. Parameters like rotational speed of reel (at 21, 25 and 35 rpm), forward speed (at 2, 3 and 4 km h−1) and cutter bar height (at 15, 25 and 35 cm) were considered for field evaluation. Results showed that optimum values for reel index (ratio of forward speed to rotational speed of reel), height of cutter bar, forward speed of combine harvester and rotational speed of reel were 1.38, 15 cm, 4 km h−1 and 21 rpm, respectively. Collected data were used to develop a model for predicting header loss as a function of parameters studied. Results from F-test between predicted and measured data were not significantly difference (p≤0.05) which is a prominent result. Keywords: Buckingham theorem, Dimensional analysis approach, Grain, Head loss, Reel index