Formation and steady state characteristics of flow field effect in the header of a stripping prior to cutting combine harvester with CFD

Abstract

In order to analyze the formation mechanism of the flow field in the header of a stripping prior to cutting combine harvester and compare the steady characteristics of the flow field generated by flat and concave combs, this study combined bench tests and computational fluid dynamics (CFD) to analyze them. During the formation of the flow field, the airflow produced “bottoming out” and “vortex” and other phenomena. At high speed, the maximum velocity of the airflow generated by the flat comb was 10.39 m s−1 and that of the concave comb was 10.59 m s−1; the flow field generated by the concave comb was better than that generated by the flat comb. Significant pulsation effects were generated in the airflow at the rice inlet and return outlet; the pulsation intensity was positively correlated with the pulsation mean velocity. At the return outlet, the turbulence of the airflow generated by the concave comb rotation was higher than that of the airflow generated by the flat comb rotation for both low and high speed conditions. This study explores the characteristics of stripping loss in the header of a stripping prior to cutting combine harvester from the perspective of flow field, which provides ideas for the structural optimization of a stripping prior to cutting combine harvester and the study of stripping loss reduction in the later stage, and also provides a reference for the rational use of air flow in the rotating domain in engineering applications.