Estimation of the Screen Movement Influence on Aerodynamic Flows in the Combine Harvester Cleaning System

Abstract

The paper examines aerodynamic modeling of air flows in the cleaning system of a combine harvester. A methodology has been developed for modeling the cleaning system, taking into account the movement of its elements, such as screens and boards, using the Simcenter Amesim and Ansys Fluent software packages. The main stages of the process of aerodynamic modeling of the cleaning system are considered using the example of the combine harvester produced by OJSC “Gomselmash”. A comparative analysis of air flows in a cleaning system with moving elements and when they are fixed in the middle position in a 2D formulation was performed. The results of numerical modeling of the aerodynamics of air flows are presented in the form of numerical values at control points, and the velocity fields and streamlines of the air flow in the flow area are illustrated. The results of the comparative analysis showed that the discrepancy between the speeds and directions of the air flow at the control points is 50 % and 4.5°, respectively. It is concluded that the movements of the cleaning elements during its aerodynamic modeling must be taken into account in order to obtain a real pattern of the air flows in the flow area. The results of modeling with fixed cleaning elements can act as a preliminary calculation to check the adequacy of the model based on the results of experimental measurements in cleaning also with fixed elements. The developed methodology for modeling the aerodynamics of the cleaning flow area will be used in further studies of the cleaning system of the combine harvester to analyze the combined behavior of air flows and heaps.

Keywords

• cleaning system
• flow area
• kinematic calculation
• aerodynamic modelling
• air flows
• combine harvester