For the zone of three-directional disturbance, the new model has been developed by modification of previous ones and by assuming that soil disturbance includes the occurrence of Rankin’s zone, while the cutting zone is assumed to be limited by the section of a straight line inclined at an angle resulting from minimization of implement resistance.
It has also been assumed that the effect of inertia forces can be considered negligible because in practice there is a lack of movement of the disturbed lump by the narrow working element of the rotary
subsoiler.
This paper presents a mathematical model of the operation of a narrow working element in soil, enabling the calculation of the required driving torque under various soil conditions and variable design parameters. An empirical verification of the model is also presented.