Modeling and simulation of grain threshing and separation in threshing units—Part I

This paper presents a comprehensive and unitary stochastic mathematical model of grain threshing and separation in both axial and tangential threshing units. The derived equations describe and quantify the percentages of unthreshed grain, free grain, and separated grain (cumulative and distribution) over the length of the threshing space, be that the rotor or the concave length. Grain threshing and separation losses are also quantified. Two coefficients of the mathematical model can be expressed as functions of functional and design parameters of the threshing unit. The model was validated with data from a large database obtained from extensive testing of various axial and tangential threshing units. Exceptional agreement of predicted and experimental data shows that all equations are highly significant.