Influence of blade shape on mulcher blade air resistance

摘要

Mulching is an energy-intensive agricultural operation. The efforts to reduce the energy intensity makes the designers explore new solutions which would reduce the energy intensity. One of the possibilities to reduce the energy intensity of mulching is to use a work tool of different shape. The paper introduces comparison of several shapes of blades intended for the mulcher with vertical axis of rotation, where especially the rake and cloth angle is changed. The measurement was performed by means of a laboratory model of a one mulcher rotor and in the field conditions where the mulcher Bednar MZ 6000 with a range of 6 m and three rotors had been used. The measurement was performed particularly from the point of view of the energy loss caused by drag of knives. The measurement done by means of the model of the mulcher has confirmed the hypothesis that larger cloth causes increased resistance of the mulcher and higher rake angle results in decreased mulcher resistance. However, larger cloth may contribute to better work quality in the field conditions.