Approaches for mathematical modelling of grain separation

Abstract

This paper presents a review of former approaches for mathematical modelling of grain separationin combine harvesters and proposes a new approach on the base of extended exponentialfunctions. The model equations for the remaining unseparated grain versus the separationlength as well as for the cumulative sum of already separated grain based on empirical as wellas on statistical approaches are put together in two tables; one containing single exponentialfunctions, the other approaches with two exponential functions, to better describe the delayedseparation start at the front of the separation unit. In addition to that the extended convectiondiffusion model and an analytical approach are described.<br><br>Experimental data can be reproduced quite well by these equations, fitting the data by properdetermination of the different threshing and separation coefficients. But the influences of cropproperties, design and adjustment of the separation units on these coefficients have to beworked out in the future.