Aerodynamic properties of potato tubers to airflow separation from stones and clods

Abstract

ABSTRACTSeparation of potato (Solanum tuberosum L.) tubers from clods and stones in a potato harvester is difficult. It is necessary to develop a better means of separation of tubers from other like size, shape, or weight objects. The study examined the aerodynamic properties of potato tubers terminal velocity, drag coefficient, Reynolds number, diameter of equivalent sphere, and volume shape factor to design a better air separator mechanism of varieties of potato tubers from stones and clods. The experimental and theoretical aerodynamic properties of potato tubers were determined and compared using a vertical wind tunnel. The tuber size class positively affected geometric mean diameter and mass of tubers. Variety affected tuber density with ‘Sante’ having a greater density than ‘Marfona’. The interaction of tuber size class and variety affected sphericity of tubers with increasing tuber size class causing reduced sphericity. In similar tuber size classes, ‘Marfona’ had greater sphericity compared to ‘Sante’ except for class 3 that opposite was true. Mean values of aerodynamic properties of varieties tested increased with increasing tubers size. Values of terminal velocity obtained for potato tubers were lower than expected for this product compared to other agricultural crops. Airflow can be used to separate tubers from stones and clods.