Modeling of Thresher Capacity and Fuel Consumption Equations Using Dimensional Analysis for Threshing Operation

Threshing capacity and fuel consumption in postharvest operations are the main factors in selecting a thresher. The problem was user was not easily understood the relation thresher capacity and fuel consumption. To easily understand the relationship, a model is needed for the independent and dependent factors. The model was developed for threshing capacity, and fuel consumption depends on parameter factors. The purpose of modeling is to select threshers, estimate thresher capacity, and identify direct and indirect factors. There are nine independent variables. These are: cylinder diameter (d), cylinder length (L), concave clearance (Cc), feed rate (Fr), drum speed (S), moisture content (Mc), crop straw ratio (R), spike/peg length (PL), and crop bulk density (ρ) and The Buckingham, pi theorem is used in basic dimensional. The threshing capacity and fuel consumption were developed. The equation was TC is equal to d2vρ (L*d-1, L*d-1, Fr *d-2Vρ) MC* 𝑆R and for fuel consumption of stationary thresher was Fc is equal to d2v (L*d-1, L*d-1, Fr*d-2Vρ) MC* 𝑆R developed. The performance investigation was conducted at three levels of drum speed (1000, 1100, and 1200 rpm) and feed rate (600, 700, and 800 kg h-1) with split-plot experimental design. The maximum threshing capacity is 234.22 kg h-1 at feed rate 800 kg h-1 and a drum speed of 1200 rpm and it consume 2.245 L h-1. The lowest threshing capacity is 223.20 kg h-1 at drum speed is 1000 rpm and the feed rate is 600 kg h-1 with fuel consumption is 2.00 L h-1. The equation developed contributed to research in that it helped researchers and designers easily understand the relation of thresher performance determinants. Consequently, using a model created by dimensional analysis is the most effective method for comprehending thresher-related parameters as result, as the speed of the drum increases, the thresher capacity increases as fuel consumption increases. Therefore, the developed model is a simple and easy way to choose and design the thresher.