Calculation of optimal power and energy saturation of an agricultural tractor

Calculation of the optimum power, operating weight and energy saturation of the agricultural tractor at which the minimum fuel consumption and optimum performance are achieved is an actual task of the tractor theory. The purpose of the study is to determine the optimal power, operating weight and energy saturation of the agricultural tractor at the minimum specific energy consumption - the ratio of energy costs when processing a unit of area to the achieved productivity. Objects of research: combined arable units with wheeled and caterpillar tractors of general purpose. Initial material: nominal traction forces accepted for different traction classes; coefficients that characterize the traction-coupling properties of the tractor; the tractor's power balance equation; skidding function; computer program to minimize the function by the dichotomy method; dependences for dimensionless coefficients that take into account the increase in the specific traction resistance of the unit with an increase in operating speed. The main research method is the calculation using nonlinear programming when the energy saturation is changed by the dichotomy method. When loading with nominal tractive effort, the nominal power of a general-purpose tractor and its maximum energy saturation are determined by the specific energy costs corresponding to the operation of the arable unit with permissible operating speed and slippage. The minimum energy saturation of the tractor is determined by the ratio of the minimum operating power to the maximum operating weight of the tractor corresponding to the maximum traction efficiency. The main conclusions: the specific energy consumption of the tractor on the process operation depends on its type and the dimensionless coefficient, taking into account the increase in the specific traction resistance of the unit with increasing speed and changing in the parabola; the nominal power of the wheeled tractor is in the interval, the lower limit of which determines the minimum specific energy consumption at the maximum traction efficiency, the upper one - the specific energy consumption at the maximum permissible speed and permissible slippage; the rated power of the crawler tractor is determined by the specific energy consumption at the maximum permissible speed and permissible slippage.